National Library of Energy BETA

Sample records for azores clouds aerosol

  1. ARM - Field Campaign - Azores: Clouds, Aerosol and Precipitation in the

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Marine Boundary Layer (CAP-MBL) govCampaignsAzores: Clouds, Aerosol and Precipitation in the Marine Boundary Layer (CAP-MBL) Campaign Links Azores Website Final Campaign Report Related Campaigns Azores: Above-Cloud Radiation Budget near Graciosa Island 2010.04.15, Miller, AMF Azores: Extension to Clouds, Aerosol and Precipitation in the Marine Boundary Layer (CAP-MBL) 2010.01.01, Wood, AMF Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send

  2. Clouds, Aerosol, and Precipitation in the Marine Boundary Layer: Analysis of Results from the ARM Mobile Facility Deployment to the Azores (2009/2010)

    SciTech Connect (OSTI)

    Wood, Robert

    2013-05-31

    The project focuses upon dataset analysis and synthesis of datasets from the AMF deployment entitled “Clouds, Aerosols, and Precipitation in the Marine Boundary Layer (CAP‐MBL)” at Graciosa Island in the Azores. Wood is serving a PI for this AMF deployment.

  3. Clouds, Aerosols and Precipitation in the Marine Boundary Layer (CAP-MBL) AMF Deployment Graciosa Island, Azores, NE Atlantic Ocean May 2009-December 2010

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    the Marine Boundary Layer (CAP-MBL) Graciosa Island, Azores, NE Atlantic Ocean May 2009-December 2010 Rob Wood, University of Washington CAP-MBL Proposal Team AMF Deployment Team Thanks to Mark Miller: AMF Site Scientist Kim Nitschke: AMF Site Manager Importance of Low-Clouds for Climate Imperative that we understand the processes controlling the formation, maintenance and dissipation of low clouds in order to improve their representation in climate models. Which clouds matter for climate

  4. A study of cloud and drizzle properties in the Azores using Doppler...

    Office of Scientific and Technical Information (OSTI)

    in the Azores using Doppler Radar spectra Citation Details In-Document Search Title: A study of cloud and drizzle properties in the Azores using Doppler Radar spectra ...

  5. Marine Boundary Layer Cloud Observations in the Azores (Journal...

    Office of Scientific and Technical Information (OSTI)

    Marine Boundary Layer Cloud Observations in the Azores Citation Details ... Publication Date: 2012-11-01 OSTI Identifier: 1059795 Report Number(s): BNL--98829-2012-JA Journal ID: ISSN ...

  6. ARM - Field Campaign - Azores: Above-Cloud Radiation Budget near Graciosa

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Island Above-Cloud Radiation Budget near Graciosa Island Campaign Links "Clouds, aerosols, and precipitation in the marine boundary layer: An ARM Mobile Facility deployment." Bulletin of the American Meteorological Society, 96(3), doi: 10.1175/bams-d-13-00180.1 ARM Data Discovery Browse Data Related Campaigns Azores: Clouds, Aerosol and Precipitation in the Marine Boundary Layer (CAP-MBL) 2009.05.01, Wood, AMF Comments? We would love to hear from you! Send us a note below or call

  7. A study of cloud and drizzle properties in the Azores using Doppler...

    Office of Scientific and Technical Information (OSTI)

    A study of cloud and drizzle properties in the Azores using Doppler Radar spectra Citation Details In-Document Search Title: A study of cloud and drizzle properties in the Azores using ...

  8. Cloud Property Retrieval Products for Graciosa Island, Azores

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Dong, Xiquan

    The motivation for developing this product was to use the Dong et al. 1998 method to retrieve cloud microphysical properties, such as cloud droplet effective radius, cloud droplets number concentration, and optical thickness. These retrieved properties have been used to validate the satellite retrieval, and evaluate the climate simulations and reanalyses. We had been using this method to retrieve cloud microphysical properties over ARM SGP and NSA sites. We also modified the method for the AMF at Shouxian, China and some IOPs, e.g. ARM IOP at SGP in March, 2000. The ARSCL data from ARM data archive over the SGP and NSA have been used to determine the cloud boundary and cloud phase. For these ARM permanent sites, the ARSCL data was developed based on MMCR measurements, however, there were no data available at the Azores field campaign. We followed the steps to generate this derived product and also include the MPLCMASK cloud retrievals to determine the most accurate cloud boundaries, including the thin cirrus clouds that WACR may under-detect. We use these as input to retrieve the cloud microphysical properties. Due to the different temporal resolutions of the derived cloud boundary heights product and the cloud properties product, we submit them as two separate netcdf files.

  9. Cloud Property Retrieval Products for Graciosa Island, Azores

    SciTech Connect (OSTI)

    Dong, Xiquan

    2014-05-05

    The motivation for developing this product was to use the Dong et al. 1998 method to retrieve cloud microphysical properties, such as cloud droplet effective radius, cloud droplets number concentration, and optical thickness. These retrieved properties have been used to validate the satellite retrieval, and evaluate the climate simulations and reanalyses. We had been using this method to retrieve cloud microphysical properties over ARM SGP and NSA sites. We also modified the method for the AMF at Shouxian, China and some IOPs, e.g. ARM IOP at SGP in March, 2000. The ARSCL data from ARM data archive over the SGP and NSA have been used to determine the cloud boundary and cloud phase. For these ARM permanent sites, the ARSCL data was developed based on MMCR measurements, however, there were no data available at the Azores field campaign. We followed the steps to generate this derived product and also include the MPLCMASK cloud retrievals to determine the most accurate cloud boundaries, including the thin cirrus clouds that WACR may under-detect. We use these as input to retrieve the cloud microphysical properties. Due to the different temporal resolutions of the derived cloud boundary heights product and the cloud properties product, we submit them as two separate netcdf files.

  10. Clouds, Aerosols and Precipitation in

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    the Marine Boundary Layer (CAP-MBL) Graciosa Island, Azores, NE Atlantic Ocean Graciosa Island, Azores, NE Atlantic Ocean May 2009-December 2010 May 2009-December 2010 Rob Wood, University of Washington Rob Wood, University of Washington AMF Deployment Team Thanks to Mark Miller: AMF Site Scientist Mark Miller: AMF Site Scientist Kim Nitschke: AMF Site Manager CAP-MBL Proposal Team Importance of Low-Clouds for Climate Imperative that we understand the processes controlling the formation,

  11. Scanning Cloud Radar Observations at Azores: Preliminary 3D Cloud Products

    SciTech Connect (OSTI)

    Kollias, P.; Johnson, K.; Jo, I.; Tatarevic, A.; Giangrande, S.; Widener, K.; Bharadwaj, N.; Mead, J.

    2010-03-15

    The deployment of the Scanning W-Band ARM Cloud Radar (SWACR) during the AMF campaign at Azores signals the first deployment of an ARM Facility-owned scanning cloud radar and offers a prelude for the type of 3D cloud observations that ARM will have the capability to provide at all the ARM Climate Research Facility sites by the end of 2010. The primary objective of the deployment of Scanning ARM Cloud Radars (SACRs) at the ARM Facility sites is to map continuously (operationally) the 3D structure of clouds and shallow precipitation and to provide 3D microphysical and dynamical retrievals for cloud life cycle and cloud-scale process studies. This is a challenging task, never attempted before, and requires significant research and development efforts in order to understand the radar's capabilities and limitations. At the same time, we need to look beyond the radar meteorology aspects of the challenge and ensure that the hardware and software capabilities of the new systems are utilized for the development of 3D data products that address the scientific needs of the new Atmospheric System Research (ASR) program. The SWACR observations at Azores provide a first look at such observations and the challenges associated with their analysis and interpretation. The set of scan strategies applied during the SWACR deployment and their merit is discussed. The scan strategies were adjusted for the detection of marine stratocumulus and shallow cumulus that were frequently observed at the Azores deployment. Quality control procedures for the radar reflectivity and Doppler products are presented. Finally, preliminary 3D-Active Remote Sensing of Cloud Locations (3D-ARSCL) products on a regular grid will be presented, and the challenges associated with their development discussed. In addition to data from the Azores deployment, limited data from the follow-up deployment of the SWACR at the ARM SGP site will be presented. This effort provides a blueprint for the effort required for the

  12. Cloud Property Retrieval Products for Graciosa Island, Azores...

    Office of Scientific and Technical Information (OSTI)

    We had been using this method to retrieve cloud microphysical properties over ARM SGP and NSA sites. We also modified the method for the AMF at Shouxian, China and some IOPs, e.g. ...

  13. The LANL Cloud-Aerosol Model

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    that incorporates two unique aspects in its formulation. First, the model employs a nonlinear solver that requires cloud-aerosol parameterizations be smooth or contain reasonable...

  14. Clouds, aerosol, and precipitation in the Marine Boundary Layer: An ARM mobile facility deployment

    SciTech Connect (OSTI)

    Wood, Robert; Luke, Ed; Wyant, Matthew; Bretherton, Christopher S.; Remillard, Jasmine; Kollias, Pavlos; Fletcher, Jennifer; Stemmler, Jayson; deSzoeke, S.; Yuter, Sandra; Miller, Matthew; Mechem, David; Tselioudis, George; Chiu, Christine; Mann, Julia; O Connor, Ewan; Hogan, Robin; Dong, Xiquan; Miller, Mark; Ghate, Virendra; Jefferson, Anne; Min, Qilong; Minnis, Patrick; Palinkonda, Rabindra; Albrecht, Bruce; Hannay, Cecile; Lin, Yanluan

    2014-04-27

    The Clouds, Aerosol, and Precipitation in the Marine Boundary Layer (CAP-MBL) deployment at Graciosa Island in the Azores generated a 21-month (April 2009-December 2010) comprehensive dataset documenting clouds, aerosols, and precipitation using the Atmospheric Radiation Measurement Program (ARM) Mobile Facility (AMF). The scientific aim of the deployment is to gain improved understanding of the interactions of clouds, aerosols, and precipitation in the marine boundary layer. Graciosa Island straddles the boundary between the subtropics and midlatitudes in the Northeast Atlantic Ocean and consequently experiences a great diversity of meteorological and cloudiness conditions. Low clouds are the dominant cloud type, with stratocumulus and cumulus occurring regularly. Approximately half of all clouds contained precipitation detectable as radar echoes below the cloud base. Radar and satellite observations show that clouds with tops from 1-11 km contribute more or less equally to surface-measured precipitation at Graciosa. A wide range of aerosol conditions was sampled during the deployment consistent with the diversity of sources as indicated by back-trajectory analysis. Preliminary findings suggest important two-way interactions between aerosols and clouds at Graciosa, with aerosols affecting light precipitation and cloud radiative properties while being controlled in part by precipitation scavenging.The data from Graciosa are being compared with short-range forecasts made with a variety of models. A pilot analysis with two climate and two weather forecast models shows that they reproduce the observed time-varying vertical structure of lower-tropospheric cloud fairly well but the cloud-nucleating aerosol concentrations less well. The Graciosa site has been chosen to be a permanent fixed ARM site that became operational in October 2013.

  15. Clouds, aerosol, and precipitation in the Marine Boundary Layer: An ARM mobile facility deployment

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Wood, Robert; Luke, Ed; Wyant, Matthew; Bretherton, Christopher S.; Remillard, Jasmine; Kollias, Pavlos; Fletcher, Jennifer; Stemmler, Jayson; deSzoeke, S.; Yuter, Sandra; et al

    2014-04-27

    The Clouds, Aerosol, and Precipitation in the Marine Boundary Layer (CAP-MBL) deployment at Graciosa Island in the Azores generated a 21-month (April 2009-December 2010) comprehensive dataset documenting clouds, aerosols, and precipitation using the Atmospheric Radiation Measurement Program (ARM) Mobile Facility (AMF). The scientific aim of the deployment is to gain improved understanding of the interactions of clouds, aerosols, and precipitation in the marine boundary layer. Graciosa Island straddles the boundary between the subtropics and midlatitudes in the Northeast Atlantic Ocean and consequently experiences a great diversity of meteorological and cloudiness conditions. Low clouds are the dominant cloud type, with stratocumulusmore » and cumulus occurring regularly. Approximately half of all clouds contained precipitation detectable as radar echoes below the cloud base. Radar and satellite observations show that clouds with tops from 1-11 km contribute more or less equally to surface-measured precipitation at Graciosa. A wide range of aerosol conditions was sampled during the deployment consistent with the diversity of sources as indicated by back-trajectory analysis. Preliminary findings suggest important two-way interactions between aerosols and clouds at Graciosa, with aerosols affecting light precipitation and cloud radiative properties while being controlled in part by precipitation scavenging.The data from Graciosa are being compared with short-range forecasts made with a variety of models. A pilot analysis with two climate and two weather forecast models shows that they reproduce the observed time-varying vertical structure of lower-tropospheric cloud fairly well but the cloud-nucleating aerosol concentrations less well. The Graciosa site has been chosen to be a permanent fixed ARM site that became operational in October 2013.« less

  16. Clouds, Aerosols, and Precipitation in the Marine Boundary Layer: An Arm Mobile Facility Deployment

    SciTech Connect (OSTI)

    Wood, Robert; Wyant, Matthew; Bretherton, Christopher S.; Rémillard, Jasmine; Kollias, Pavlos; Fletcher, Jennifer; Stemmler, Jayson; de Szoeke, Simone; Yuter, Sandra; Miller, Matthew; Mechem, David; Tselioudis, George; Chiu, J. Christine; Mann, Julian A. L.; O’Connor, Ewan J.; Hogan, Robin J.; Dong, Xiquan; Miller, Mark; Ghate, Virendra; Jefferson, Anne; Min, Qilong; Minnis, Patrick; Palikonda, Rabindra; Albrecht, Bruce; Luke, Ed; Hannay, Cecile; Lin, Yanluan

    2015-03-01

    The Clouds, Aerosol, and Precipitation in the Marine Boundary Layer (CAP-MBL) 38 deployment at Graciosa Island in the Azores generated a 21 month (April 2009-December 2010) 39 comprehensive dataset documenting clouds, aerosols and precipitation using the Atmospheric 40 Radiation Measurement (ARM) Mobile Facility (AMF). The scientific aim of the deployment is 41 to gain improved understanding of the interactions of clouds, aerosols and precipitation in the 42 marine boundary layer. 43 Graciosa Island straddles the boundary between the subtropics and midlatitudes in the 44 Northeast Atlantic Ocean, and consequently experiences a great diversity of meteorological and 45 cloudiness conditions. Low clouds are the dominant cloud type, with stratocumulus and cumulus 46 occurring regularly. Approximately half of all clouds contained precipitation detectable as radar 47 echoes below the cloud base. Radar and satellite observations show that clouds with tops from 1-48 11 km contribute more or less equally to surface-measured precipitation at Graciosa. A wide 49 range of aerosol conditions was sampled during the deployment consistent with the diversity of 50 sources as indicated by back trajectory analysis. Preliminary findings suggest important two-way 51 interactions between aerosols and clouds at Graciosa, with aerosols affecting light precipitation 52 and cloud radiative properties while being controlled in part by precipitation scavenging. 53 The data from at Graciosa are being compared with short-range forecasts made a variety 54 of models. A pilot analysis with two climate and two weather forecast models shows that they 55 reproduce the observed time-varying vertical structure of lower-tropospheric cloud fairly well, 56 but the cloud-nucleating aerosol concentrations less well. The Graciosa site has been chosen to 57 be a long-term ARM site that became operational in October 2013.

  17. ARM: Aerosol Observing System (AOS): cloud condensation nuclei...

    Office of Scientific and Technical Information (OSTI)

    Title: ARM: Aerosol Observing System (AOS): cloud condensation nuclei data Aerosol Observing System (AOS): cloud condensation nuclei data Authors: Scott Smith ; Cynthia Salwen ; ...

  18. Atmospheric Radiation Measurement (ARM) Data from the Eastern North Atlantic Site (ENA), Graciosa Island, Azores

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Wood, Robert

    From May 2009 through December 2010, the ARM Mobile Facility obtained data from a location near the airport on Graciosa Island to support the Clouds, Aerosol, and Precipitation in the Marine Boundary Layer (CAP-MBL) field campaign. The campaign was led by principal investigator Robert Wood. Results from this campaign confirmed that the Azores have the ideal mix of conditions to study how clouds, aerosols, and precipitation interact. This new observation site will have significant enhancements to instruments previously deployed to the Azores, including a Ka-/W-band scanning cloud radar, precipitation radar, and Doppler lidar. It has the full support of the Azorean government and collaborators at the University of the Azores. Los Alamos National Laboratory will operate the site for the ARM Facility.

  19. ARM - Field Campaign - Biogenic Aerosols - Effects on Clouds and Climate

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Climate Campaign Links Final Campaign Summary BAECC Website ARM Data Discovery Browse Data Related Campaigns Biogenic Aerosols - Effects on Clouds and Climate: Cloud OD Sensor TWST 2014.06.15, Scott, AMF Biogenic Aerosols - Effects on Clouds and Climate: Extended Radiosonde IOP 2014.05.01, Nicoll, AMF Biogenic Aerosols - Effects on Clouds and Climate: FIGAERO-ToF-CIMS Instrument in Hyytiala with AMF-2 2014.04.01, Thornton, AMF Biogenic Aerosols - Effects on Clouds and Climate: Snowfall

  20. Biogenic Aerosols-Effects on Clouds and Climate (BAECC) Final...

    Office of Scientific and Technical Information (OSTI)

    Title: Biogenic Aerosols-Effects on Clouds and Climate (BAECC) Final Campaign Summary Atmospheric aerosol particles impact human health in urban environments, while on regional and ...

  1. ARM - Field Campaign - Aerosol and Cloud Experiments in the Eastern...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    horizontal variabilities of aerosol, trace gases, cloud, drizzle, and atmospheric thermodynamics are critically needed for understanding and quantifying the budget of MBL aerosol,...

  2. Cloud Condensation Nuclei Activity of Aerosols during GoAmazon...

    Office of Scientific and Technical Information (OSTI)

    microphysical properties of the aerosol." The Observations and Modeling of the Green Ocean Amazon (GoAmazon 201415) study seeks to understand how aerosol and cloud life cycles ...

  3. Biogenic Aerosols„Effects on Clouds and Climate (BAECC)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Biogenic Aerosols-Effects on Clouds and Climate (BAECC) Final Campaign Summary T Petj ... DOESC-ARM-15-051 Biogenic Aerosols-Effects on Clouds and Climate (BAECC) Final Campaign ...

  4. ARM - Field Campaign - ARM Cloud Aerosol Precipitation Experiment (ACAPEX)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Campaign Links Field Campaign Report ACAPEX Website ARM Data Discovery Browse Data Related Campaigns ARM Cloud Aerosol Precipitation Experiment (ACAPEX): Aerosols and Ocean Science Expedition (AEROSE) 2015.01.14, Morris, AMF ARM Cloud Aerosol Precipitation Experiment (ACAPEX): Ship-Based Ice Nuclei Collections 2015.01.14, DeMott, AMF ARM Cloud Aerosol Precipitation Experiment (ACAPEX): Aerial Observations 2015.01.14, Leung, AAF Comments? We would love to hear from you! Send us a note below or

  5. ARM Cloud-Aerosol-Precipitation Experiment (ACAPEX) Field Campaign...

    Office of Scientific and Technical Information (OSTI)

    2015, a multi-agency field campaign that aims to improve understanding of atmospheric rivers and aerosol sources and transport that influence cloud and precipitation processes. ...

  6. Overview of the COPS Aerosol and Cloud Microphysics (ACM) Subgroup...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    COPS Aerosol and Cloud Microphysics (ACM) Subgroup Activities Dave Turner Space Science ... (ACM) - Chairs: Susanne Crewell, Dave Turner, Stephen Mobbs ACM Scientific Questions * ...

  7. BAECC Biogenic Aerosols - Effects on Clouds and Climate (Technical...

    Office of Scientific and Technical Information (OSTI)

    The main research goal was to understand the role of biogenic aerosols in cloud formation. ... Country of Publication: United States Language: English Subject: 54 ENVIRONMENTAL SCIENCES ...

  8. Understanding the Effect of Aerosol Properties on Cloud Droplet...

    Office of Scientific and Technical Information (OSTI)

    5-055 ENERGY Science Understanding the Effect of Aerosol Properties on Cloud Droplet Formation during TCAP Field Campaign Report D Cziczo May 2016 ARM CLIMATE RESEARCH FACILITY ...

  9. "Lidar Investigations of Aerosol, Cloud, and Boundary Layer Properties...

    Office of Scientific and Technical Information (OSTI)

    Technical Report: "Lidar Investigations of Aerosol, Cloud, and Boundary Layer Properties Over the ARM ACRF Sites" Citation Details In-Document Search Title: "Lidar Investigations ...

  10. The Radiative Role of Free Tropospheric Aerosols and Marine Clouds over the Central North Atlantic

    SciTech Connect (OSTI)

    Mazzoleni, Claudio; Kumar, Sumit; Wright, Kendra; Kramer, Louisa; Mazzoleni, Lynn; Owen, Robert; Helmig, Detlev

    2014-12-09

    The scientific scope of the project was to exploit the unique location of the Pico Mountain Observatory (PMO) located in the summit caldera of the Pico Volcano in Pico Island in the Azores, for atmospheric studies. The observatory, located at 2225m a.s.l., typically samples free tropospheric aerosols laying above the marine low-level clouds and long-range transported from North America. The broad purpose of this research was to provide the scientific community with a better understanding of fundamental physical processes governing the effects of aerosols on radiative forcing and climate; with the ultimate goal of improving our abilities to understand past climate and to predict future changes through numerical models. The project was 'exploratory' in nature, with the plan to demonstrate the feasibility of deploying for the first time, an extensive aerosol research package at PMO. One of the primary activities was to test the deployment of these instruments at the site, to collect data during the 2012 summer season, and to further develop the infrastructure and the knowledge for performing novel research at PMO in follow-up longer-term aerosol-cloud studies. In the future, PMO could provide an elevated research outpost to support the renewed DOE effort in the Azores that was intensified in 2013 with the opening of the new sea-level ARM-DOE Eastern North Atlantic permanent facility at Graciosa Island. During the project period, extensive new data sets were collected for the planned 2012 season. Thanks to other synergistic activities and opportunities, data collection was then successfully extended to 2013 and 2014. Highlights of the scientific findings during this project include: a) biomass burning contribute significantly to the aerosol loading in the North Atlantic free troposphere; however, long-range transported black carbon concentrations decreased substantially in the last decade. b) Single black carbon particles – analyzed off-line at the electron

  11. Surface based remote sensing of aerosol-cloud interactions

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Surface based remote sensing of aerosol-cloud interactions Feingold, Graham NOAA/Environmental Technology Laboratory Frisch, Shelby NOAA/Environmental Technology Laboratory Min, Qilong State University of New York at Albany Category: Cloud Properties We will present an analysis of the effect of aerosol on clouds at the Southern Great Plains ARM site. New methods for retrieving cloud droplet effective radius with radar (MMCR), multifilter rotating shadowband radiometer (MFRSR), and microwave

  12. Impact of aerosol size representation on modeling aerosol-cloud interactions: AEROSOL SIZE REPRESENTATION

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Zhang, Y.; Easter, R. C.; Ghan, S. J.; Abdul-Razzak, H.

    2002-11-07

    We use a 1-D version of a climate-aerosol-chemistry model with both modal and sectional aerosol size representations to evaluate the impact of aerosol size representation on modeling aerosol-cloud interactions in shallow stratiform clouds observed during the 2nd Aerosol Characterization Experiment. Both the modal (with prognostic aerosol number and mass or prognostic aerosol number, surface area and mass, referred to as the Modal-NM and Modal-NSM) and the sectional approaches (with 12 and 36 sections) predict total number and mass for interstitial and activated particles that are generally within several percent of references from a high resolution 108-section approach. The modal approachmore » with prognostic aerosol mass but diagnostic number (referred to as the Modal-M) cannot accurately predict the total particle number and surface areas, with deviations from the references ranging from 7-161%. The particle size distributions are sensitive to size representations, with normalized absolute differences of up to 12% and 37% for the 36- and 12-section approaches, and 30%, 39%, and 179% for the Modal-NSM, Modal-NM, and Modal-M, respectively. For the Modal-NSM and Modal-NM, differences from the references are primarily due to the inherent assumptions and limitations of the modal approach. In particular, they cannot resolve the abrupt size transition between the interstitial and activated aerosol fractions. For the 12- and 36-section approaches, differences are largely due to limitations of the parameterized activation for non-log-normal size distributions, plus the coarse resolution for the 12-section case. Differences are larger both with higher aerosol (i.e., less complete activation) and higher SO2 concentrations (i.e., greater modification of the initial aerosol distribution).« less

  13. ARM - Field Campaign - Cloud, Aerosol, and Complex Terrain Interactions

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    (CACTI) govCampaignsCloud, Aerosol, and Complex Terrain Interactions (CACTI) Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Cloud, Aerosol, and Complex Terrain Interactions (CACTI) 2018.08.15 - 2019.04.30 Lead Scientist : Adam Varble Abstract General circulation models and downscaled regional models exhibit persistent biases in deep convective initiation location and timing, cloud top height, stratiform area and precipitation

  14. ARM - Field Campaign - Biogenic Aerosols - Effects on Clouds and Climate:

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Cloud OD Sensor TWST Cloud OD Sensor TWST Campaign Links Field Campaign Report ARM Data Discovery Browse Data Related Campaigns Biogenic Aerosols - Effects on Clouds and Climate 2014.02.01, Petäjä, AMF Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Biogenic Aerosols - Effects on Clouds and Climate: Cloud OD Sensor TWST 2014.06.15 - 2014.08.31 Lead Scientist : Herman Scott For data sets, see below. Abstract This deployment

  15. Evaluating aerosol indirect effect through marine stratocumulus clouds

    SciTech Connect (OSTI)

    Kogan, Z.N.; Kogan, Y.L.; Lilly, D.K.

    1996-04-01

    During the last decade much attention has been focused on anthropogenic aerosols and their radiative influence on the global climate. Charlson et al. and Penner et al. have demonstrated that tropospheric aerosols and particularly anthropogenic sulfate aerosols may significantly contribute to the radiative forcing exerting a cooling influence on climate (-1 to -2 W/m{sup 2}) which is comparable in magnitude to greenhouse forcing, but opposite in sign. Aerosol particles affect the earth`s radiative budget either directly by scattering and absorption of solar radiation by themselves or indirectly by altering the cloud radiative properties through changes in cloud microstructure. Marine stratocumulus cloud layers and their possible cooling influence on the atmosphere as a result of pollution are of special interest because of their high reflectivity, durability, and large global cover. We present an estimate of thet aerosol indirect effect, or, forcing due to anthropogenic sulfate aerosols.

  16. ARM - Field Campaign - ARM Cloud Aerosol Precipitation Experiment...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    would love to hear from you Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : ARM Cloud Aerosol Precipitation Experiment (ACAPEX): Aerial Observations 2015.01.14...

  17. Holistic Interactions of Shallow Clouds, Aerosols, and Land-Ecosystems

    Office of Scientific and Technical Information (OSTI)

    (HI-SCALE) Science Plan (Program Document) | SciTech Connect Holistic Interactions of Shallow Clouds, Aerosols, and Land-Ecosystems (HI-SCALE) Science Plan Citation Details In-Document Search Title: Holistic Interactions of Shallow Clouds, Aerosols, and Land-Ecosystems (HI-SCALE) Science Plan Cumulus convection is an important component in the atmospheric radiation budget and hydrologic cycle over the Southern Great Plains and over many regions of the world, particularly during the

  18. Evaluating Global Aerosol Models and Aerosol and Water Vapor Properties Near Clouds

    SciTech Connect (OSTI)

    Richard A. Ferrare; David D. Turner

    2011-09-01

    Project goals: (1) Use the routine surface and airborne measurements at the ARM SGP site, and the routine surface measurements at the NSA site, to continue our evaluations of model aerosol simulations; (2) Determine the degree to which the Raman lidar measurements of water vapor and aerosol scattering and extinction can be used to remotely characterize the aerosol humidification factor; (3) Use the high temporal resolution CARL data to examine how aerosol properties vary near clouds; and (4) Use the high temporal resolution CARL and Atmospheric Emitted Radiance Interferometer (AERI) data to quantify entrainment in optically thin continental cumulus clouds.

  19. Indirect and semi-direct aerosol campaign: The impact of Arctic aerosols on clouds

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    McFarquhar, Greg M.; Ghan, Steven; Verlinde, Johannes; Korolev, Alexei; Strapp, J. Walter; Schmid, Beat; Tomlinson, Jason M.; Wolde, Menqistu; Brooks, Sarah D.; Cziczo, Dan; et al

    2011-02-01

    A comprehensive dataset of microphysical and radiative properties of aerosols and clouds in the boundary layer in the vicinity of Barrow, Alaska, was collected in April 2008 during the Indirect and Semi-Direct Aerosol Campaign (ISDAC). ISDAC's primary aim was to examine the effects of aerosols, including those generated by Asian wildfires, on clouds that contain both liquid and ice. ISDAC utilized the Atmospheric Radiation Measurement Pro- gram's permanent observational facilities at Barrow and specially deployed instruments measuring aerosol, ice fog, precipitation, and radiation. The National Research Council of Canada Convair-580 flew 27 sorties and collected data using an unprecedented 41more » stateof- the-art cloud and aerosol instruments for more than 100 h on 12 different days. Aerosol compositions, including fresh and processed sea salt, biomassburning particles, organics, and sulfates mixed with organics, varied between flights. Observations in a dense arctic haze on 19 April and above, within, and below the single-layer stratocumulus on 8 and 26 April are enabling a process-oriented understanding of how aerosols affect arctic clouds. Inhomogeneities in reflectivity, a close coupling of upward and downward Doppler motion, and a nearly constant ice profile in the single-layer stratocumulus suggests that vertical mixing is responsible for its longevity observed during ISDAC. Data acquired in cirrus on flights between Barrow and Fairbanks, Alaska, are improving the understanding of the performance of cloud probes in ice. Furthermore, ISDAC data will improve the representation of cloud and aerosol processes in models covering a variety of spatial and temporal scales, and determine the extent to which surface measurements can provide retrievals of aerosols, clouds, precipitation, and radiative heating.« less

  20. Indirect and Semi-Direct Aerosol Campaign: The Impact of Arctic Aerosols on Clouds

    SciTech Connect (OSTI)

    McFarquhar, Greg; Ghan, Steven J.; Verlinde, J.; Korolev, Alexei; Strapp, J. Walter; Schmid, Beat; Tomlinson, Jason M.; Wolde, Mengistu; Brooks, Sarah D.; Cziczo, Daniel J.; Dubey, Manvendra K.; Fan, Jiwen; Flynn, Connor J.; Gultepe, Ismail; Hubbe, John M.; Gilles, Mary K.; Laskin, Alexander; Lawson, Paul; Leaitch, W. R.; Liu, Peter S.; Liu, Xiaohong; Lubin, Dan; Mazzoleni, Claudio; Macdonald, A. M.; Moffet, Ryan C.; Morrison, H.; Ovchinnikov, Mikhail; Shupe, Matthew D.; Turner, David D.; Xie, Shaocheng; Zelenyuk, Alla; Bae, Kenny; Freer, Matthew; Glen, Andrew

    2011-02-01

    A comprehensive dataset of microphysical and radiative properties of aerosols and clouds in the arctic boundary layer in the vicinity of Barrow, Alaska was collected in April 2008 during the Indirect and Semi-Direct Aerosol Campaign (ISDAC) sponsored by the Department of Energy Atmospheric Radiation Measurement (ARM) and Atmospheric Science Programs. The primary aim of ISDAC was to examine indirect effects of aerosols on clouds that contain both liquid and ice water. The experiment utilized the ARM permanent observational facilities at the North Slope of Alaska (NSA) in Barrow. These include a cloud radar, a polarized micropulse lidar, and an atmospheric emitted radiance interferometer as well as instruments specially deployed for ISDAC measuring aerosol, ice fog, precipitation and spectral shortwave radiation. The National Research Council of Canada Convair-580 flew 27 sorties during ISDAC, collecting data using an unprecedented 42 cloud and aerosol instruments for more than 100 hours on 12 different days. Data were obtained above, below and within single-layer stratus on 8 April and 26 April 2008. These data enable a process-oriented understanding of how aerosols affect the microphysical and radiative properties of arctic clouds influenced by different surface conditions. Observations acquired on a heavily polluted day, 19 April 2008, are enhancing this understanding. Data acquired in cirrus on transit flights between Fairbanks and Barrow are improving our understanding of the performance of cloud probes in ice. Ultimately the ISDAC data will be used to improve the representation of cloud and aerosol processes in models covering a variety of spatial and temporal scales, and to determine the extent to which long-term surface-based measurements can provide retrievals of aerosols, clouds, precipitation and radiative heating in the Arctic.

  1. Posters Cloud Parameterizations in Global Climate Models: The Role of Aerosols

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Posters Cloud Parameterizations in Global Climate Models: The Role of Aerosols J. E. Penner and C. C. Chuang Lawrence Livermore National Laboratory Livermore, California Introduction Aerosols influence warm clouds in two ways. First, they determine initial drop size distributions, thereby influencing the albedo of clouds. Second, they determine the lifetime of clouds, thereby possibly changing global cloud cover statistics. At the present time, neither effect of aerosols on clouds is included

  2. BAECC Biogenic Aerosols - Effects on Clouds and Climate

    SciTech Connect (OSTI)

    Petäjä, Tuukka; Moisseev, Dmitri; Sinclair, Victoria; O'Connor, Ewan J.; Manninen, Antti J.; Levula, Janne; Väänänen, Riikka; Heikkinen, Liine; Äijälä, Mikko; Aalto, Juho; Bäck, Jaana

    2015-11-01

    “Biogenic Aerosols - Effects on Clouds and Climate (BAECC)”, featured the U.S. Department of Energy’s Atmospheric Radiation Measurement (ARM) Program’s 2nd Mobile Facility (AMF2) in Hyytiälä, Finland. It operated for an 8-month intensive measurement campaign from February to September 2014. The main research goal was to understand the role of biogenic aerosols in cloud formation. One of the reasons to perform BAECC study in Hyytiälä was the fact that it hosts SMEAR-II (Station for Measuring Forest Ecosystem-Atmosphere Relations), which is one of the world’s most comprehensive surface in-situ observation sites in a boreal forest environment. The station has been measuring atmospheric aerosols, biogenic emissions and an extensive suite of parameters relevant to atmosphere-biosphere interactions continuously since 1996. The BAECC enables combining vertical profiles from AMF2 with surface-based in-situ SMEAR-II observations and allows the processes at the surface to be directly related to processes occurring throughout the entire tropospheric column. With the inclusion of extensive surface precipitation measurements, and intensive observation periods involving aircraft flights and novel radiosonde launches, the complementary observations of AMF2 and SMEAR-II provide a unique opportunity for investigating aerosol-cloud interactions, and cloud-to-precipitation processes. The BAECC dataset will initiate new opportunities for evaluating and improving models of aerosol sources and transport, cloud microphysical processes, and boundary-layer structures.

  3. Cloud Droplet Spectral Shape Sheds New Light on Aerosol- Cloud-Interaction Regimes

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Droplet Spectral Shape Sheds New Light on Aerosol- Cloud-Interaction Regimes For original submission and image(s), see ARM Research Highlights http://www.arm.gov/science/highlights/ Research Highlight Despite decades of research, aerosol indirect effects remain among the most uncertain climate forcings according to the latest Intergovernmental Panel on Climate Change report. Furthermore, climate models tend to overestimate the cooling of aerosol indirect effects and are more susceptible than

  4. ARM - Field Campaign - Holistic Interactions of Shallow Clouds, Aerosols,

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and Land-Ecosystems (HI-SCALE): Nanoparticle Composition and Precursors Nanoparticle Composition and Precursors Related Campaigns Holistic Interactions of Shallow Clouds, Aerosols, and Land-Ecosystems (HI-SCALE) 2016.04.24, Fast, AAF Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Holistic Interactions of Shallow Clouds, Aerosols, and Land-Ecosystems (HI-SCALE): Nanoparticle Composition and Precursors 2016.08.21 - 2016.09.27 Lead

  5. ARM - Field Campaign - Biogenic Aerosols - Effects on Clouds and Climate:

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Extended Radiosonde IOP Extended Radiosonde IOP ARM Data Discovery Browse Data Related Campaigns Biogenic Aerosols - Effects on Clouds and Climate 2014.02.01, Petäjä, AMF Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Biogenic Aerosols - Effects on Clouds and Climate: Extended Radiosonde IOP 2014.05.01 - 2014.08.31 Lead Scientist : Keri Nicoll For data sets, see below. Abstract Modified meteorological radiosondes have been

  6. ARM - Field Campaign - Biogenic Aerosols - Effects on Clouds and Climate:

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Snowfall Experiment Snowfall Experiment ARM Data Discovery Browse Data Related Campaigns Biogenic Aerosols - Effects on Clouds and Climate 2014.02.01, Petäjä, AMF Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Biogenic Aerosols - Effects on Clouds and Climate: Snowfall Experiment 2014.02.01 - 2014.04.30 Lead Scientist : Dmitri Moisseev For data sets, see below. Abstract The snowfall measurement campaign, took place during AMF2

  7. ARM - Field Campaign - Measurement of Aerosols, Radiation and Clouds over

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    the Southern Ocean (MARCUS: Ice Nucleating Particle Measurements) Ocean (MARCUS: Ice Nucleating Particle Measurements) Related Campaigns Measurement of Aerosols, Radiation and Clouds over the Southern Oceans (MARCUS) 2017.09.01, McFarquhar, AMF Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Measurement of Aerosols, Radiation and Clouds over the Southern Ocean (MARCUS: Ice Nucleating Particle Measurements) 2017.09.01 - 2018.04.30

  8. Impact of aerosol size representation on modeling aerosol-cloud...

    Office of Scientific and Technical Information (OSTI)

    SciTech Connect Search Results Journal Article: Impact of aerosol size representation on ... OSTI Identifier: 15003527 Report Number(s): PNWD-SA--5600 Journal ID: ISSN 0148-0227 ...

  9. Effects of Ocean Ecosystem on Marine Aerosol-Cloud Interaction

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Meskhidze, Nicholas; Nenes, Athanasios

    2010-01-01

    Using smore » atellite data for the surface ocean, aerosol optical depth (AOD), and cloud microphysical parameters, we show that statistically significant positive correlations exist between ocean ecosystem productivity, the abundance of submicron aerosols, and cloud microphysical properties over different parts of the remote oceans. The correlation coefficient for remotely sensed surface chlorophyll a concentration ([Chl- a ]) and liquid cloud effective radii over productive areas of the oceans varies between − 0.2 and − 0.6 . Special attention is given to identifying (and addressing) problems from correlation analysis used in the previous studies that can lead to erroneous conclusions. A new approach (using the difference between retrieved AOD and predicted sea salt aerosol optical depth, AOD diff ) is developed to explore causal links between ocean physical and biological systems and the abundance of cloud condensation nuclei (CCN) in the remote marine atmosphere. We have found that over multiple time periods, 550 nm AOD diff (sensitive to accumulation mode aerosol, which is the prime contributor to CCN) correlates well with [Chl- a ] over the productive waters of the Southern Ocean. Since [Chl- a ] can be used as a proxy of ocean biological productivity, our analysis demonstrates the role of ocean ecology in contributing CCN, thus shaping the microphysical properties of low-level marine clouds.« less

  10. Evaluating Global Aerosol Models and Aerosol and Water Vapor Properties Near Clouds

    SciTech Connect (OSTI)

    Turner, David, D.; Ferrare, Richard, A.

    2011-07-06

    The 'Evaluating Global Aerosol Models and Aerosol and Water Vapor Properties Near Clouds' project focused extensively on the analysis and utilization of water vapor and aerosol profiles derived from the ARM Raman lidar at the Southern Great Plains ARM site. A wide range of different tasks were performed during this project, all of which improved quality of the data products derived from the lidar or advanced the understanding of atmospheric processes over the site. These activities included: upgrading the Raman lidar to improve its sensitivity; participating in field experiments to validate the lidar aerosol and water vapor retrievals; using the lidar aerosol profiles to evaluate the accuracy of the vertical distribution of aerosols in global aerosol model simulations; examining the correlation between relative humidity and aerosol extinction, and how these change, due to horizontal distance away from cumulus clouds; inferring boundary layer turbulence structure in convective boundary layers from the high-time-resolution lidar water vapor measurements; retrieving cumulus entrainment rates in boundary layer cumulus clouds; and participating in a field experiment that provided data to help validate both the entrainment rate retrievals and the turbulent profiles derived from lidar observations.

  11. Biogenic Aerosols - Effects on Climate and Clouds. Cloud Optical...

    Office of Scientific and Technical Information (OSTI)

    A good range of cloud conditions were observed from clear sky to heavy rainfall. Authors: Niple, E. R. 1 ; Scott, H. E. 1 + Show Author Affiliations Aerodyne Research, Inc., ...

  12. Parameterizations of Cloud Microphysics and Indirect Aerosol...

    Office of Scientific and Technical Information (OSTI)

    A recent report published by the National Academy of Science states "The greatest ... 1977 and the "semi-direct" effect on cloud coverage e.g., Ackerman et al., 2000. ...

  13. Impact of aerosol size representation on modeling aerosol-cloud interactions

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Zhang, Y.; Easter, R. C.; Ghan, S. J.; Abdul-Razzak, H.

    2002-11-07

    In this study, we use a 1-D version of a climate-aerosol-chemistry model with both modal and sectional aerosol size representations to evaluate the impact of aerosol size representation on modeling aerosol-cloud interactions in shallow stratiform clouds observed during the 2nd Aerosol Characterization Experiment. Both the modal (with prognostic aerosol number and mass or prognostic aerosol number, surface area and mass, referred to as the Modal-NM and Modal-NSM) and the sectional approaches (with 12 and 36 sections) predict total number and mass for interstitial and activated particles that are generally within several percent of references from a high resolution 108-section approach.more » The modal approach with prognostic aerosol mass but diagnostic number (referred to as the Modal-M) cannot accurately predict the total particle number and surface areas, with deviations from the references ranging from 7-161%. The particle size distributions are sensitive to size representations, with normalized absolute differences of up to 12% and 37% for the 36- and 12-section approaches, and 30%, 39%, and 179% for the Modal-NSM, Modal-NM, and Modal-M, respectively. For the Modal-NSM and Modal-NM, differences from the references are primarily due to the inherent assumptions and limitations of the modal approach. In particular, they cannot resolve the abrupt size transition between the interstitial and activated aerosol fractions. For the 12- and 36-section approaches, differences are largely due to limitations of the parameterized activation for non-log-normal size distributions, plus the coarse resolution for the 12-section case. Differences are larger both with higher aerosol (i.e., less complete activation) and higher SO2 concentrations (i.e., greater modification of the initial aerosol distribution).« less

  14. Parameterizations of Cloud Microphysics and Indirect Aerosol Effects

    SciTech Connect (OSTI)

    Tao, Wei-Kuo

    2014-05-19

    1. OVERVIEW Aerosols and especially their effect on clouds are one of the key components of the climate system and the hydrological cycle [Ramanathan et al., 2001]. Yet, the aerosol effect on clouds remains largely unknown and the processes involved not well understood. A recent report published by the National Academy of Science states "The greatest uncertainty about the aerosol climate forcing - indeed, the largest of all the uncertainties about global climate forcing - is probably the indirect effect of aerosols on clouds [NRC, 2001]." The aerosol effect on clouds is often categorized into the traditional "first indirect (i.e., Twomey)" effect on the cloud droplet sizes for a constant liquid water path [Twomey, 1977] and the "semi-direct" effect on cloud coverage [e.g., Ackerman et al., 2000]. Enhanced aerosol concentrations can also suppress warm rain processes by producing a narrow droplet spectrum that inhibits collision and coalescence processes [e.g., Squires and Twomey, 1961; Warner and Twomey, 1967; Warner, 1968; Rosenfeld, 1999]. The aerosol effect on precipitation processes, also known as the second type of aerosol indirect effect [Albrecht, 1989], is even more complex, especially for mixed-phase convective clouds. Table 1 summarizes the key observational studies identifying the microphysical properties, cloud characteristics, thermodynamics and dynamics associated with cloud systems from high-aerosol continental environments. For example, atmospheric aerosol concentrations can influence cloud droplet size distributions, warm-rain process, cold-rain process, cloud-top height, the depth of the mixed phase region, and occurrence of lightning. In addition, high aerosol concentrations in urban environments could affect precipitation variability by providing an enhanced source of cloud condensation nuclei (CCN). Hypotheses have been developed to explain the effect of urban regions on convection and precipitation [van den Heever and Cotton, 2007 and Shepherd

  15. Aerosols and Clouds: In Cahoots to Change Climate

    SciTech Connect (OSTI)

    Berg, Larry

    2014-03-29

    Key knowledge gaps persist despite advances in the scientific understanding of how aerosols and clouds evolve and affect climate. The Two-Column Aerosol Project, or TCAP, was designed to provide a detailed set of observations to tackle this area of unknowns. Led by PNNL atmospheric scientist Larry Berg, ARM's Climate Research Facility was deployed in Cape Cod, Massachusetts for the 12-month duration of TCAP, which came to a close in June 2013. "We are developing new tools to look at particle chemistry, like our mass spectrometer used in TCAP that can tell us the individual chemical composition of an aerosol," said Berg. "Then, we'll run our models and compare it with the data that we have to make sure we're getting correct answers and make sure our climate models are reflecting the best information."

  16. Aerosols and Clouds: In Cahoots to Change Climate

    ScienceCinema (OSTI)

    Berg, Larry

    2014-06-02

    Key knowledge gaps persist despite advances in the scientific understanding of how aerosols and clouds evolve and affect climate. The Two-Column Aerosol Project, or TCAP, was designed to provide a detailed set of observations to tackle this area of unknowns. Led by PNNL atmospheric scientist Larry Berg, ARM's Climate Research Facility was deployed in Cape Cod, Massachusetts for the 12-month duration of TCAP, which came to a close in June 2013. "We are developing new tools to look at particle chemistry, like our mass spectrometer used in TCAP that can tell us the individual chemical composition of an aerosol," said Berg. "Then, we'll run our models and compare it with the data that we have to make sure we're getting correct answers and make sure our climate models are reflecting the best information."

  17. Cloud/Aerosol Parameterizations: Application and Improvement of General Circulation Models

    SciTech Connect (OSTI)

    Penner, Joyce

    2012-06-30

    One of the biggest uncertainties associated with climate models and climate forcing is the treatment of aerosols and their effects on clouds. The effect of aerosols on clouds can be divided into two components: The first indirect effect is the forcing associated with increases in droplet concentrations; the second indirect effect is the forcing associated with changes in liquid water path, cloud morphology, and cloud lifetime. Both are highly uncertain. This project applied a cloud-resolving model to understand the response of clouds under a variety of conditions to changes in aerosols. These responses are categorized according to the large-scale meteorological conditions that lead to the response. Meteorological conditions were sampled from various fields, which, together with a global aerosol model determination of the change in aerosols from present day to pre-industrial conditions, was used to determine a first order estimate of the response of global cloud fields to changes in aerosols. The response of the clouds in the NCAR CAM3 GCM coupled to our global aerosol model were tested by examining whether the response is similar to that of the cloud resolving model and methods for improving the representation of clouds and cloud/aerosol interactions were examined.

  18. The role of aerosols in cloud drop parameterizations and its applications in global climate models

    SciTech Connect (OSTI)

    Chuang, C.C.; Penner, J.E.

    1996-04-01

    The characteristics of the cloud drop size distribution near cloud base are initially determined by aerosols that serve as cloud condensation nuclei and the updraft velocity. We have developed parameterizations relating cloud drop number concentration to aerosol number and sulfate mass concentrations and used them in a coupled global aerosol/general circulation model (GCM) to estimate the indirect aerosol forcing. The global aerosol model made use of our detailed emissions inventories for the amount of particulate matter from biomass burning sources and from fossil fuel sources as well as emissions inventories of the gas-phase anthropogenic SO{sub 2}. This work is aimed at validating the coupled model with the Atmospheric Radiation Measurement (ARM) Program measurements and assessing the possible magnitude of the aerosol-induced cloud effects on climate.

  19. Efficacy of Aerosol-Cloud Interactions Under Varying Meteorological Conditions: Southern Great Plains Vs. Pt. Reyes

    SciTech Connect (OSTI)

    Dunn, M.; Schwartz, S.; Kim, B.-G.; Miller, M.; Liu, Y.; Min, Q.

    2008-03-10

    Several studies have demonstrated that cloud dynamical processes such as entrainment mixing may be the primary modulator of cloud optical properties in certain situations. For example, entrainment of dry air alters the cloud drop size distribution by enhancing drop evaporation. However, the effect of entrainment mixing and other forms or turbulence is still quite uncertain. Although these factors and aerosol-cloud interactions should be considered together when evaluating the efficacy of aerosol indirect effects, the underlying mechanisms appear to be dependent upon each other. In addition, accounting for them is impossible with the current understanding of aerosol indirect effect. Therefore, careful objective screening and analysis of observations are needed to determine the extent to which mixing related properties affect cloud optical properties, apart from the aerosol first indirect effect. This study addresses the role of aerosol-cloud interactions in the context of varying meteorological conditions based on ARM data obtained at the Southern Great Plains (SGP) site in Oklahoma and at Pt. Reyes, California. Previous analyses of the continental stratiform clouds at the SGP site have shown that the thicker clouds of high liquid water path (LWP) tend to contain sub adiabatic LWPs. These sub adiabatic LWPs, which result from active mixing processes, correspond to a lower susceptibility of the clouds to aerosol-cloud interactions, and, hence, to reduced aerosol indirect effects. In contrast, the consistently steady and thin maritime stratus clouds observed at Pt. Reyes are much closer to adiabatic. These clouds provide an excellent benchmark for the study of the aerosol influence on modified marine clouds relative to continental clouds, since they form in a much more homogeneous meteorological environment than those at the continental site.

  20. ARM: 10-minute Raman Lidar: aerosol depolarization profiles and single layer cloud optical depths from first Turner algorithm

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Chitra Sivaraman; Connor Flynn

    1998-03-01

    10-minute Raman Lidar: aerosol depolarization profiles and single layer cloud optical depths from first Turner algorithm

  1. ARM: 10-minute Raman Lidar: aerosol depolarization profiles and single layer cloud optical depths from first Turner algorithm

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Chitra Sivaraman; Connor Flynn

    10-minute Raman Lidar: aerosol depolarization profiles and single layer cloud optical depths from first Turner algorithm

  2. ARM Cloud Aerosol Precipitation Experiment (ACAPEX) Science Plan

    SciTech Connect (OSTI)

    Leung, L. R.; Prather, K.; Ralph, R.; Rosenfeld, D.; Spackman, R.; DeMott, P.; Fairall, C.; Fan, J.; Hagos, S.; Hughes, M.; Long, C.; Rutledge, S.; Waliser, D.; Wang, H.

    2014-09-01

    The western U.S. receives precipitation predominantly during the cold season when storms approach from the Pacific Ocean. The snowpack that accumulates during winter storms provides about 70-90% of water supply for the region. Understanding and modeling the fundamental processes that govern the large precipitation variability and extremes in the western U.S. is a critical test for the ability of climate models to predict the regional water cycle, including floods and droughts. Two elements of significant importance in predicting precipitation variability in the western U.S. are atmospheric rivers and aerosols. Atmospheric rivers (ARs) are narrow bands of enhanced water vapor associated with the warm sector of extratropical cyclones over the Pacific and Atlantic oceans. Because of the large lower-tropospheric water vapor content, strong atmospheric winds and neutral moist static stability, some ARs can produce heavy precipitation by orographic enhancement during landfall on the U.S. West Coast. While ARs are responsible for a large fraction of heavy precipitation in that region during winter, much of the rest of the orographic precipitation occurs in post-frontal clouds, which are typically quite shallow, with tops just high enough to pass the mountain barrier. Such clouds are inherently quite susceptible to aerosol effects on both warm rain and ice precipitation-forming processes.

  3. Vertical microphysical profiles of convective clouds as a tool for obtaining aerosol cloud-mediated climate forcings

    SciTech Connect (OSTI)

    Rosenfeld, Daniel

    2015-12-23

    Quantifying the aerosol/cloud-mediated radiative effect at a global scale requires simultaneous satellite retrievals of cloud condensation nuclei (CCN) concentrations and cloud base updraft velocities (Wb). Hitherto, the inability to do so has been a major cause of high uncertainty regarding anthropogenic aerosol/cloud-mediated radiative forcing. This can be addressed by the emerging capability of estimating CCN and Wb of boundary layer convective clouds from an operational polar orbiting weather satellite. Our methodology uses such clouds as an effective analog for CCN chambers. The cloud base supersaturation (S) is determined by Wb and the satellite-retrieved cloud base drop concentrations (Ndb), which is the same as CCN(S). Developing and validating this methodology was possible thanks to the ASR/ARM measurements of CCN and vertical updraft profiles. Validation against ground-based CCN instruments at the ARM sites in Oklahoma, Manaus, and onboard a ship in the northeast Pacific showed a retrieval accuracy of ±25% to ±30% for individual satellite overpasses. The methodology is presently limited to boundary layer not raining convective clouds of at least 1 km depth that are not obscured by upper layer clouds, including semitransparent cirrus. The limitation for small solar backscattering angles of <25º restricts the satellite coverage to ~25% of the world area in a single day. This methodology will likely allow overcoming the challenge of quantifying the aerosol indirect effect and facilitate a substantial reduction of the uncertainty in anthropogenic climate forcing.

  4. Development and testing of an aerosol-stratus cloud parameterization scheme for middle and high latitudes

    SciTech Connect (OSTI)

    Olsson, P.Q.; Meyers, M.P.; Kreidenweis, S.; Cotton, W.R.

    1996-04-01

    The aim of this new project is to develop an aerosol/cloud microphysics parameterization of mixed-phase stratus and boundary layer clouds. Our approach is to create, test, and implement a bulk-microphysics/aerosol model using data from Atmospheric Radiation Measurement (ARM) Cloud and Radiation Testbed (CART) sites and large-eddy simulation (LES) explicit bin-resolving aerosol/microphysics models. The primary objectives of this work are twofold. First, we need the prediction of number concentrations of activated aerosol which are transferred to the droplet spectrum, so that the aerosol population directly affects the cloud formation and microphysics. Second, we plan to couple the aerosol model to the gas and aqueous-chemistry module that will drive the aerosol formation and growth. We begin by exploring the feasibility of performing cloud-resolving simulations of Arctic stratus clouds over the North Slope CART site. These simulations using Colorado State University`s regional atmospheric modeling system (RAMS) will be useful in designing the structure of the cloud-resolving model and in interpreting data acquired at the North Slope site.

  5. Holistic Interactions of Shallow Clouds, Aerosols, and Land-Ecosystems (HI-SCALE) Science Plan

    SciTech Connect (OSTI)

    Fast, JD; Berg, LK

    2015-12-01

    Cumulus convection is an important component in the atmospheric radiation budget and hydrologic cycle over the Southern Great Plains and over many regions of the world, particularly during the summertime growing season when intense turbulence induced by surface radiation couples the land surface to clouds. Current convective cloud parameterizations contain uncertainties resulting in part from insufficient coincident data that couples cloud macrophysical and microphysical properties to inhomogeneities in boundary layer and aerosol properties. The Holistic Interactions of Shallow Clouds, Aerosols, and Land-Ecosystems (HI-SCALE) campaign is designed to provide a detailed set of measurements that are needed to obtain a more complete understanding of the life cycle of shallow clouds by coupling cloud macrophysical and microphysical properties to land surface properties, ecosystems, and aerosols. HI-SCALE consists of 2, 4-week intensive observational periods, one in the spring and the other in the late summer, to take advantage of different stages and distribution of “greenness” for various types of vegetation in the vicinity of the Atmospheric Radiation and Measurement (ARM) Climate Research Facility’s Southern Great Plains (SGP) site as well as aerosol properties that vary during the growing season. Most of the proposed instrumentation will be deployed on the ARM Aerial Facility (AAF) Gulfstream 1 (G-1) aircraft, including those that measure atmospheric turbulence, cloud water content and drop size distributions, aerosol precursor gases, aerosol chemical composition and size distributions, and cloud condensation nuclei concentrations. Routine ARM aerosol measurements made at the surface will be supplemented with aerosol microphysical properties measurements. The G-1 aircraft will complete transects over the SGP Central Facility at multiple altitudes within the boundary layer, within clouds, and above clouds.

  6. New understanding and quantification of the regime dependence of aerosol-cloud interaction for studying aerosol indirect effects

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Chen, Jingyi; Liu, Yangang; Zhang, Minghua; Peng, Yiran

    2016-02-28

    In this study, aerosol indirect effects suffer from large uncertainty in climate models and among observations. This study focuses on two plausible factors: regime dependence of aerosol-cloud interactions and the effect of cloud droplet spectral shape. We show, using a new parcel model, that combined consideration of droplet number concentration (Nc) and relative dispersion (ε, ratio of standard deviation to mean radius of the cloud droplet size distribution) better characterizes the regime dependence of aerosol-cloud interactions than considering Nc alone. Given updraft velocity (w), ε increases with increasing aerosol number concentration (Na) in the aerosol-limited regime, peaks in the transitionalmore » regime, and decreases with further increasing Na in the updraft-limited regime. This new finding further reconciles contrasting observations in literature and reinforces the compensating role of dispersion effect. The nonmonotonic behavior of ε further quantifies the relationship between the transitional Na and w that separates the aerosol- and updraft-limited regimes.« less

  7. Science Plan Biogenic Aerosols - Effects on Clouds and Climate...

    Office of Scientific and Technical Information (OSTI)

    In spite of recent advances in the understanding of aerosol formation processes and the links between aerosol dynamics and biosphere-atmosphere-climate interactions, great ...

  8. “Lidar Investigations of Aerosol, Cloud, and Boundary Layer Properties Over the ARM ACRF Sites”

    SciTech Connect (OSTI)

    Ferrare, Richard; Turner, David

    2015-01-13

    Project goals; Characterize the aerosol and ice vertical distributions over the ARM NSA site, and in particular to discriminate between elevated aerosol layers and ice clouds in optically thin scattering layers; Characterize the water vapor and aerosol vertical distributions over the ARM Darwin site, how these distributions vary seasonally, and quantify the amount of water vapor and aerosol that is above the boundary layer; Use the high temporal resolution Raman lidar data to examine how aerosol properties vary near clouds; Use the high temporal resolution Raman lidar and Atmospheric Emitted Radiance Interferometer (AERI) data to quantify entrainment in optically thin continental cumulus clouds; and Use the high temporal Raman lidar data to continue to characterize the turbulence within the convective boundary layer and how the turbulence statistics (e.g., variance, skewness) is correlated with larger scale variables predicted by models.

  9. DE/SC-ARM/TR-130 Aerosol Observing System Cloud Condensation...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    DESC-ARMTR-130 Aerosol Observing System Cloud Condensation Nuclei Average (AOSCCNAVG) Value-Added Product Y Shi A Jefferson C Flynn July 2013 DOESC-ARMTR-130 DISCLAIMER This ...

  10. Investigation of warm-cloud microphysics using a multi-component cloud model: Interactive effects of the aerosol spectrum. Master's thesis

    SciTech Connect (OSTI)

    Zahn, S.G.

    1993-12-01

    Clouds, especially low, warm, boundary-layer clouds, play an important role in regulating the earth's climate due to their significant contribution to the global albedo. The radiative effects of individual clouds are controlled largely by cloud microstructure, which is itself sensitive to the concentration and spectral distribution of the atmospheric aerosol. Increases in aerosol particle concentrations from anthropogenic activity could result in increased cloud albedo and global cloudiness, increasing the amount of reflected solar radiation. However, the effects of increased aerosol particle concentrations could be offset by the presence of giant or ultragiant aerosol particles. A one-dimensional, multi-component microphysical cloud model has been used to demonstrate the effects of aerosol particle spectral variations on the microstructure of warm clouds. Simulations performed with this model demonstrate that the introduction of increased concentrations of giant aerosol particles has a destabilizing effect on the cloud microstructure. Also, it is shown that warm-cloud microphysical processes modify the aerosol particle spectrum, favoring the generation of the largest sized particles via the collision-coalescence process. These simulations provide further evidence that the effect of aerosol particles on cloud microstructure must be addressed when considering global climate forecasts.

  11. Analyzing signatures of aerosol-cloud interactions from satelliteretrievals and the GISS GCM to constrain the aerosol indirecteffect

    SciTech Connect (OSTI)

    Menon, S.; Del Genio, A.D.; Kaufman, Y.; Bennartz, R.; Koch, D.; Loeb, N.; Orlikowski, D.

    2007-10-01

    Evidence of aerosol-cloud interactions are evaluated using satellite data from MODIS, CERES, AMSR-E, reanalysis data from NCEP and data from the NASA Goddard Institute for Space Studies climate model. We evaluate a series of model simulations: (1) Exp N- aerosol direct radiative effects; (2) Exp C- Like Exp N but with aerosol effects on liquid-phase cumulus and stratus clouds; (3) Exp CN- Like Exp C but with model wind fields nudged to reanalysis data. Comparison between satellite-retrieved data and model simulations for June to August 2002, over the Atlantic Ocean indicate the following: a negative correlation between aerosol optical thickness (AOT) and cloud droplet effective radius (R{sub eff}) for all cases and satellite data, except for Exp N; a weak but negative correlation between liquid water path (LWP) and AOT for MODIS and CERES; and a robust increase in cloud cover with AOT for both MODIS and CERES. In all simulations, there is a positive correlation between AOT and both cloud cover and LWP (except in the case of LWP-AOT for Exp CN). The largest slopes are obtained for Exp N, implying that meteorological variability may be an important factor. The main fields associated with AOT variability in NCEP/MODIS data are warmer temperatures and increased subsidence for less clean cases, not well captured by the model. Simulated cloud fields compared with an enhanced data product from MODIS and AMSR-E indicate that model cloud thickness is over-predicted and cloud droplet number is within retrieval uncertainties. Since LWP fields are comparable this implies an under-prediction of R{sub eff} and thus an over-prediction of the indirect effect.

  12. An Observed Signature of Aerosol Effect on Cloud Droplet Radii from a

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Decade of Observations at a Mid-Continental Site An Observed Signature of Aerosol Effect on Cloud Droplet Radii from a Decade of Observations at a Mid-Continental Site Min, Qilong State University of New York at Albany Duan, Minzheng State University of New York at Albany Harrison, Lee State University of New York Joseph, Everette Howard University Category: Aerosols Continuing observations of aerosol and cloud optical property have been made using MFRSR and MWR at the ARM SGP site since

  13. Study of Mechanisms of Aerosol Indirect Effects on Glaciated Clouds: Progress during the Project Final Technical Report

    SciTech Connect (OSTI)

    2013-10-18

    This 3-year project has studied how aerosol pollution influences glaciated clouds. The tool applied has been an 'aerosol-cloud model'. It is a type of Cloud-System Resolving Model (CSRM) modified to include 2-moment bulk microphysics and 7 aerosol species, as described by Phillips et al. (2009, 2013). The study has been done by, first, improving the model and then performing sensitivity studies with validated simulations of a couple of observed cases from ARM. These are namely the Tropical Warm Pool International Cloud Experiment (TWP-ICE) over the tropical west Pacific and the Cloud and Land Surface Interaction Campaign (CLASIC) over Oklahoma. During the project, sensitivity tests with the model showed that in continental clouds, extra liquid aerosols (soluble aerosol material) from pollution inhibited warm rain processes for precipitation production. This promoted homogeneous freezing of cloud droplets and aerosols. Mass and number concentrations of cloud-ice particles were boosted. The mean sizes of cloud-ice particles were reduced by the pollution. Hence, the lifetime of glaciated clouds, especially ice-only clouds, was augmented due to inhibition of sedimentation and ice-ice aggregation. Latent heat released from extra homogeneous freezing invigorated convective updrafts, and raised their maximum cloud-tops, when aerosol pollution was included. In the particular cases simulated in the project, the aerosol indirect effect of glaciated clouds was twice than of (warm) water clouds. This was because glaciated clouds are higher in the troposphere than water clouds and have the first interaction with incoming solar radiation. Ice-only clouds caused solar cooling by becoming more extensive as a result of aerosol pollution. This 'lifetime indirect effect' of ice-only clouds was due to higher numbers of homogeneously nucleated ice crystals causing a reduction in their mean size, slowing the ice-crystal process of snow production and slowing sedimentation. In addition

  14. Observed correlations between aerosol and cloud properties in an Indian Ocean trade cumulus regime

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Pistone, Kristina; Praveen, Puppala S.; Thomas, Rick M.; Ramanathan, Veerabhadran; Wilcox, Eric M.; Bender, Frida A.-M.

    2016-04-27

    There are many contributing factors which determine the micro- and macrophysical properties of clouds, including atmospheric vertical structure, dominant meteorological conditions, and aerosol concentration, all of which may be coupled to one another. In the quest to determine aerosol effects on clouds, these potential relationships must be understood. Here we describe several observed correlations between aerosol conditions and cloud and atmospheric properties in the Indian Ocean winter monsoon season.In the CARDEX (Cloud, Aerosol, Radiative forcing, Dynamics EXperiment) field campaign conducted in February and March 2012 in the northern Indian Ocean, continuous measurements were made of atmospheric precipitable water vapor (PWV)more » and the liquid water path (LWP) of trade cumulus clouds, concurrent with measurements of water vapor flux, cloud and aerosol vertical profiles, meteorological data, and surface and total-column aerosol from instrumentation at a ground observatory and on small unmanned aircraft. We present observations which indicate a positive correlation between aerosol and cloud LWP only when considering cases with low atmospheric water vapor (PWV < 40 kg m–2), a criterion which acts to filter the data to control for the natural meteorological variability in the region.We then use the aircraft and ground-based measurements to explore possible mechanisms behind this observed aerosol–LWP correlation. The increase in cloud liquid water is found to coincide with a lowering of the cloud base, which is itself attributable to increased boundary layer humidity in polluted conditions. High pollution is found to correlate with both higher temperatures and higher humidity measured throughout the boundary layer. A large-scale analysis, using satellite observations and meteorological reanalysis, corroborates these covariations: high-pollution cases are shown to originate as a highly polluted boundary layer air mass approaching the observatory from a

  15. Clouds, Aerosol, and Precipitation in the Marine Boundary Layer (CAP-MBL) Final Campaign Report

    SciTech Connect (OSTI)

    Wood, R.

    2016-01-01

    The extensive coverage of low clouds over the subtropical eastern oceans greatly impacts the current climate. In addition, the response of low clouds to changes in atmospheric greenhouse gases and aerosols is a major source of uncertainty, which thwarts accurate prediction of future climate change. Low clouds are poorly simulated in climate models, partly due to inadequate long-term simultaneous observations of their macrophysical and microphysical structure, radiative effects, and associated aerosol distribution in regions where their impact is greatest. The thickness and extent of subtropical low clouds is dependent on tight couplings between surface fluxes of heat and moisture, radiative cooling, boundary layer turbulence, and precipitation (much of which evaporates before reaching the ocean surface and is closely connected to the abundance of cloud condensation nuclei). These couplings have been documented as a result of past field programs and model studies. However, extensive research is still required to achieve a quantitative understanding sufficient for developing parameterizations, which adequately predict aerosol indirect effects and low cloud response to climate perturbations. This is especially true of the interactions between clouds, aerosol, and precipitation. These processes take place in an ever-changing synoptic environment that can confound interpretation of short time period observations.

  16. Evaluating Clouds, Aerosols, and their Interactions in Three Global Climate Models using COSP and Satellite Observations

    SciTech Connect (OSTI)

    Ban-Weiss, George; Jin, Ling; Bauer, S.; Bennartz, Ralph; Liu, Xiaohong; Zhang, Kai; Ming, Yi; Guo, Huan; Jiang, Jonathan

    2014-09-23

    Accurately representing aerosol-cloud interactions in global climate models is challenging. As parameterizations evolve, it is important to evaluate their performance with appropriate use of observations. In this work we compare aerosols, clouds, and their interactions in three climate models (AM3, CAM5, ModelE) to MODIS satellite observations. Modeled cloud properties were diagnosed using the CFMIP Observations Simulator Package (COSP). Cloud droplet number concentrations (N) were derived using the same algorithm for both satellite-simulated model values and observations. We find that aerosol optical depth tau simulated by models is similar to observations. For N, AM3 and CAM5 capture the observed spatial pattern of higher values in near-coast versus remote ocean regions, though modeled values in general are higher than observed. In contrast, ModelE simulates lower N in most near-coast versus remote regions. Aerosol- cloud interactions were computed as the sensitivity of N to tau for marine liquid clouds off the coasts of South Africa and Eastern Asia where aerosol pollution varies in time. AM3 and CAM5 are in most cases more sensitive than observations, while the sensitivity for ModelE is statistically insignificant. This widely used sensitivity could be subject to misinterpretation due to the confounding influence of meteorology on both aerosols and clouds. A simple framework for assessing the N – tau sensitivity at constant meteorology illustrates that observed sensitivity can change from positive to statistically insignificant when including the confounding influence of relative humidity. Satellite simulated values of N were compared to standard model output and found to be higher with a bias of 83 cm-3.

  17. Process-model Simulations of Cloud Albedo Enhancement by Aerosols in the Arctic

    SciTech Connect (OSTI)

    Kravitz, Benjamin S.; Wang, Hailong; Rasch, Philip J.; Morrison, H.; Solomon, Amy

    2014-11-17

    A cloud-resolving model is used to simulate the effectiveness of Arctic marine cloud brightening via injection of cloud condensation nuclei (CCN). An updated cloud microphysical scheme is employed, with prognostic CCN and cloud particle numbers in both liquid and mixed-phase marine low clouds. Injection of CCN into the marine boundary layer can delay the collapse of the boundary layer and increase low-cloud albedo. Because nearly all of the albedo effects are in the liquid phase due to the removal of ice water by snowfall when ice processes are involved, albedo increases are stronger for pure liquid clouds than mixed-phase clouds. Liquid precipitation can be suppressed by CCN injection, whereas ice precipitation (snow) is affected less; thus the effectiveness of brightening mixed-phase clouds is lower than for liquid-only clouds. CCN injection into a clean regime results in a greater albedo increase than injection into a polluted regime, consistent with current knowledge about aerosol-cloud interactions. Unlike previous studies investigating warm clouds, dynamical changes in circulation due to precipitation changes are small.

  18. A New WRF-Chem Treatment for Studying Regional Scale Impacts of Cloud-Aerosol Interactions in Parameterized Cumuli

    SciTech Connect (OSTI)

    Berg, Larry K.; Shrivastava, ManishKumar B.; Easter, Richard C.; Fast, Jerome D.; Chapman, Elaine G.; Liu, Ying

    2015-01-01

    A new treatment of cloud-aerosol interactions within parameterized shallow and deep convection has been implemented in WRF-Chem that can be used to better understand the aerosol lifecycle over regional to synoptic scales. The modifications to the model to represent cloud-aerosol interactions include treatment of the cloud dropletnumber mixing ratio; key cloud microphysical and macrophysical parameters (including the updraft fractional area, updraft and downdraft mass fluxes, and entrainment) averaged over the population of shallow clouds, or a single deep convective cloud; and vertical transport, activation/resuspension, aqueous chemistry, and wet removal of aerosol and trace gases in warm clouds. Thesechanges have been implemented in both the WRF-Chem chemistry packages as well as the Kain-Fritsch cumulus parameterization that has been modified to better represent shallow convective clouds. Preliminary testing of the modified WRF-Chem has been completed using observations from the Cumulus Humilis Aerosol Processing Study (CHAPS) as well as a high-resolution simulation that does not include parameterized convection. The simulation results are used to investigate the impact of cloud-aerosol interactions on the regional scale transport of black carbon (BC), organic aerosol (OA), and sulfate aerosol. Based on the simulations presented here, changes in the column integrated BC can be as large as -50% when cloud-aerosol interactions are considered (due largely to wet removal), or as large as +35% for sulfate in non-precipitating conditions due to the sulfate production in the parameterized clouds. The modifications to WRF-Chem version 3.2.1 are found to account for changes in the cloud drop number concentration (CDNC) and changes in the chemical composition of cloud-drop residuals in a way that is consistent with observations collected during CHAPS. Efforts are currently underway to port the changes described here to WRF-Chem version 3.5, and it is anticipated that they

  19. ARM - Field Campaign - Cirrus Clouds and Aerosol Properties Campaign

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Lead Scientist : Shadrian Strong For data sets, see below. Abstract Through the National Geospatial-Intelligence Agency Characterization of Cirrus and Aerosol Properties (CCAP) ...

  20. Cloud Condensation Nuclei Activity of Aerosols During GoAmazon...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ... The contrasts between pristine air and the pollution plume provided excellent opportunities to look into how and to what extent different aerosol size and compositions impact the ...

  1. Model analysis of the anthropogenic aerosol effect on clouds over East Asia

    SciTech Connect (OSTI)

    Gao, Yi; Zhang, Meigen; Liu, Xiaohong; Zhao, Chun

    2012-01-16

    A coupled meteorology and aerosol/chemistry model WRF-Chem (Weather Research and Forecast model coupled with Chemistry) was used to conduct a pair of simulations with present-day (PD) and preindustrial (PI) emissions over East Asia to examine the aerosol indirect effect on clouds. As a result of an increase in aerosols in January, the cloud droplet number increased by 650 cm{sup -3} over the ocean and East China, 400 cm{sup -3} over Central and Southwest China, and less than 200 cm{sup -3} over North China. The cloud liquid water path (LWP) increased by 40-60 g m{sup -2} over the ocean and Southeast China and 30 g m{sup -2} over Central China; the LWP increased less than 5 g m{sup -2} or decreased by 5 g m{sup -2} over North China. The effective radius (Re) decreased by more than 4 {mu}m over Southwest, Central, and Southeast China and 2 {mu}m over North China. In July, variations in cloud properties were more uniform; the cloud droplet number increased by approximately 250-400 cm{sup -3}, the LWP increased by approximately 30-50 g m{sup -2}, and Re decreased by approximately 3 {mu}m over most regions of China. In response to cloud property changes from PI to PD, shortwave (SW) cloud radiative forcing strengthened by 30 W m{sup -2} over the ocean and 10 W m{sup -2} over Southeast China, and it weakened slightly by approximately 2-10 W m{sup -2} over Central and Southwest China in January. In July, SW cloud radiative forcing strengthened by 15 W m{sup -2} over Southeast and North China and weakened by 10 W m{sup -2} over Central China. The different responses of SW cloud radiative forcing in different regions was related to cloud feedbacks and natural variability.

  2. Science Plan Biogenic Aerosols – Effects on Clouds and Climate (BAECC)

    SciTech Connect (OSTI)

    Petäjä, T

    2013-12-01

    Atmospheric aerosol particles impact human health in urban environments, while on regional and global scales they can affect climate patterns, the hydrological cycle, and the intensity of radiation that reaches the Earth’s surface. In spite of recent advances in the understanding of aerosol formation processes and the links between aerosol dynamics and biosphere-atmosphere-climate interactions, great challenges remain in the analysis of related processes on a global scale. Boreal forests, situated in a circumpolar belt in the northern latitudes throughout the United States, Canada, Russia and Scandinavia, are among the most active areas of atmospheric aerosol formation among all biomes. The formation of aerosol particles and their growth to the sizes of cloud condensation nuclei in these areas are associated with biogenic volatile organic emissions from vegetation and soil.

  3. Holistic Interactions of Shallow Clouds, Aerosols, and Land-Ecosystems...

    Office of Scientific and Technical Information (OSTI)

    Cumulus convection is an important component in the atmospheric radiation budget and ... when intense turbulence induced by surface radiation couples the land surface to clouds. ...

  4. Biogenic Aerosol - Effect on Clouds and Climate (BAECC-ERI)....

    Office of Scientific and Technical Information (OSTI)

    Modified meteorological radiosondes have been extensively developed at the University of Reading for measuring cloud properties, to allow measurements beyond the traditional ...

  5. Holistic Interactions of Shallow Clouds, Aerosols, and Land-Ecosystems...

    Office of Scientific and Technical Information (OSTI)

    and over many regions of the world, particularly during the summertime growing season when intense turbulence induced by surface radiation couples the land surface to clouds. ...

  6. Lidar Investigation of Tropical Nocturnal Boundary Layer Aerosols and Cloud Macrophysics

    SciTech Connect (OSTI)

    Manoj, M. G.; Devara, PC S.; Taraphdar, Sourav

    2013-10-01

    Observational evidence of two-way association between nocturnal boundary layer aerosols and cloud macrophysical properties under different meteorological conditions is reported in this paper. The study has been conducted during 2008-09 employing a high space-time resolution polarimetric micro-pulse lidar over a tropical urban station in India. Firstly, the study highlights the crucial role of boundary layer aerosols and background meteorology on the formation and structure of low-level stratiform clouds in the backdrop of different atmospheric stability conditions. Turbulent mixing induced by the wind shear at the station, which is associated with a complex terrain, is found to play a pivotal role in the formation and structural evolution of nocturnal boundary layer clouds. Secondly, it is shown that the trapping of energy in the form of outgoing terrestrial radiation by the overlying low-level clouds can enhance the aerosol mixing height associated with the nocturnal boundary layer. To substantiate this, the long-wave heating associated with cloud capping has been quantitatively estimated in an indirect way by employing an Advanced Research Weather Research and Forecasting (WRF-ARW) model version 2.2 developed by National Center for Atmospheric Research (NCAR), Colorado, USA, and supplementary data sets; and differentiated against other heating mechanisms. The present investigation as well establishes the potential of lidar remote-sensing technique in exploring some of the intriguing aspects of the cloud-environment relationship.

  7. Automated retrieval of cloud and aerosol properties from the ARM Raman lidar, part 1: feature detection

    SciTech Connect (OSTI)

    Thorsen, Tyler J.; Fu, Qiang; Newsom, Rob K.; Turner, David D.; Comstock, Jennifer M.

    2015-11-01

    A Feature detection and EXtinction retrieval (FEX) algorithm for the Atmospheric Radiation Measurement (ARM) program’s Raman lidar (RL) has been developed. Presented here is part 1 of the FEX algorithm: the detection of features including both clouds and aerosols. The approach of FEX is to use multiple quantities— scattering ratios derived using elastic and nitro-gen channel signals from two fields of view, the scattering ratio derived using only the elastic channel, and the total volume depolarization ratio— to identify features using range-dependent detection thresholds. FEX is designed to be context-sensitive with thresholds determined for each profile by calculating the expected clear-sky signal and noise. The use of multiple quantities pro-vides complementary depictions of cloud and aerosol locations and allows for consistency checks to improve the accuracy of the feature mask. The depolarization ratio is shown to be particularly effective at detecting optically-thin features containing non-spherical particles such as cirrus clouds. Improve-ments over the existing ARM RL cloud mask are shown. The performance of FEX is validated against a collocated micropulse lidar and observations from the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) satellite over the ARM Darwin, Australia site. While we focus on a specific lidar system, the FEX framework presented here is suitable for other Raman or high spectral resolution lidars.

  8. Impacts of aerosol-cloud interactions on past and future changes in tropospheric composition

    SciTech Connect (OSTI)

    Unger, N.; Menon, S.; Shindell, D. T.; Koch, D. M.

    2009-02-02

    The development of effective emissions control policies that are beneficial to both climate and air quality requires a detailed understanding of all the feedbacks in the atmospheric composition and climate system. We perform sensitivity studies with a global atmospheric composition-climate model to assess the impact of aerosols on tropospheric chemistry through their modification on clouds, aerosol-cloud interactions (ACI). The model includes coupling between both tropospheric gas-phase and aerosol chemistry and aerosols and liquid-phase clouds. We investigate past impacts from preindustrial (PI) to present day (PD) and future impacts from PD to 2050 (for the moderate IPCC A1B scenario) that embrace a wide spectrum of precursor emission changes and consequential ACI. The aerosol indirect effect (AIE) is estimated to be -2.0 Wm{sup -2} for PD-PI and -0.6 Wm{sup -2} for 2050-PD, at the high end of current estimates. Inclusion of ACI substantially impacts changes in global mean methane lifetime across both time periods, enhancing the past and future increases by 10% and 30%, respectively. In regions where pollution emissions increase, inclusion of ACI leads to 20% enhancements in in-cloud sulfate production and {approx}10% enhancements in sulfate wet deposition that is displaced away from the immediate source regions. The enhanced in-cloud sulfate formation leads to larger increases in surface sulfate across polluted regions ({approx}10-30%). Nitric acid wet deposition is dampened by 15-20% across the industrialized regions due to ACI allowing additional re-release of reactive nitrogen that contributes to 1-2 ppbv increases in surface ozone in outflow regions. Our model findings indicate that ACI must be considered in studies of methane trends and projections of future changes to particulate matter air quality.

  9. Coupling Between Oceanic Upwelling and Cloud-aerosol Properties at the AMF Point Reyes Site

    SciTech Connect (OSTI)

    Dunn, M.; Jensen, M.; Miller, M.; Kollias, P.; Bartholomew, M. J.; Turner, D.; Andrews, E.; Jefferson, A.; Daum, P.

    2008-03-10

    Cloud microphysical properties measured at the ARM Mobile Facility site located on the northern coast of California near Point Reyes, during the 2005 Marine Stratus Radiation, Aerosol and Drizzle experiment, were analyzed to determine their relationship to the coastal sea surface temperature (SST) which was characterized using measurements acquired from a National Oceanic and Atmospheric Administration offshore buoy. An increase in SST resulting from a relaxation of upwelling, occurring in the eastern Pacific Ocean off the coast of California in summer is observed to strongly correlate with nearby ground measured cloud microphysical properties and cloud condensation nuclei (CCN) concentrations. Correlations between these atmospheric and oceanic features provide insight into the interplay between the ocean and cloud radiative properties. We present evidence of this robust correlation and examine the factors controlling these features. The marine boundary layer is in direct contact with the sea surface and is strongly influenced by SST. Moisture and vertical motion are crucial ingredients for cloud development and so we examine the role of SST in providing these key components to the atmosphere. Although upwelling of cold subsurface waters is conventionally thought to increase aerosols in the region, thus increasing clouds, here we observed a relaxation of upwelling associated with changes in the structure of marine stratus clouds. As upwelling relaxes, the SST get warmer, thick clouds with high liquid water paths are observed and persist for a few days. This cycle is repeated throughout the summer upwelling season. A concomitant cyclic increase and decrease of CCN concentration is also observed. Forcing mechanisms and large-scale atmospheric features are discussed. Marine stratocumulus clouds are a critical component of the earth's radiation budget and this site provides an excellent opportunity to study the influence of SST on these clouds.

  10. Use of the ARM Measurements of Spectral Zenith Radiance for Better Understanding of 3D Cloud-Radiation Processes & Aerosol-Cloud Interaction

    SciTech Connect (OSTI)

    Chiu, Jui-Yuan Christine

    2014-04-10

    This project focuses on cloud-radiation processes in a general three-dimensional cloud situation, with particular emphasis on cloud optical depth and effective particle size. The proposal has two main parts. Part one exploits the large number of new wavelengths offered by the Atmospheric Radiation Measurement (ARM) zenith-pointing ShortWave Spectrometer (SWS), to develop better retrievals not only of cloud optical depth but also of cloud particle size. We also take advantage of the SWS’ high sampling resolution to study the “twilight zone” around clouds where strong aerosol-cloud interactions are taking place. Part two involves continuing our cloud optical depth and cloud fraction retrieval research with ARM’s 2-channel narrow vield-of-view radiometer and sunphotometer instrument by, first, analyzing its data from the ARM Mobile Facility deployments, and second, making our algorithms part of ARM’s operational data processing.

  11. Aerosol concentration and size distribution measured below, in, and above cloud from the DOE G-1 during VOCALS-REx

    SciTech Connect (OSTI)

    Kleinman L. I.; Daum, P. H.; Lee, Y.-N.; Lewis, E. R.; Sedlacek III, A. J.; Senum, G. I.; Springston, S. R.; Wang, J.; Hubbe, J.; Jayne, J.; Min, Q.; Yum, S. S.; Allen, G.

    2012-01-04

    During the VOCALS Regional Experiment, the DOE G-1 aircraft was used to sample a varying aerosol environment pertinent to properties of stratocumulus clouds over a longitude band extending 800 km west from the Chilean coast at Arica. Trace gas and aerosol measurements are presented as a function of longitude, altitude, and dew point in this study. Spatial distributions are consistent with an upper atmospheric source for O{sub 3} and South American coastal sources for marine boundary layer (MBL) CO and aerosol, most of which is acidic sulfate. Pollutant layers in the free troposphere (FT) can be a result of emissions to the north in Peru or long range transport from the west. At a given altitude in the FT (up to 3 km), dew point varies by 40 C with dry air descending from the upper atmospheric and moist air having a boundary layer (BL) contribution. Ascent of BL air to a cold high altitude results in the condensation and precipitation removal of all but a few percent of BL water along with aerosol that served as CCN. Thus, aerosol volume decreases with dew point in the FT. Aerosol size spectra have a bimodal structure in the MBL and an intermediate diameter unimodal distribution in the FT. Comparing cloud droplet number concentration (CDNC) and pre-cloud aerosol (D{sub p} > 100 nm) gives a linear relation up to a number concentration of {approx}150 cm{sup -3}, followed by a less than proportional increase in CDNC at higher aerosol number concentration. A number balance between below cloud aerosol and cloud droplets indicates that {approx}25 % of aerosol with D{sub p} > 100 nm are interstitial (not activated). A direct comparison of pre-cloud and in-cloud aerosol yields a higher estimate. Artifacts in the measurement of interstitial aerosol due to droplet shatter and evaporation are discussed. Within each of 102 constant altitude cloud transects, CDNC and interstitial aerosol were anti-correlated. An examination of one cloud as a case study shows that the

  12. Investigating ice nucleation in cirrus clouds with an aerosol-enabled Multiscale Modeling Framework

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Zhang, Chengzhu; Wang, Minghuai; Morrison, H.; Somerville, Richard C.; Zhang, Kai; Liu, Xiaohong; Li, J-L F.

    2014-11-06

    In this study, an aerosol-dependent ice nucleation scheme [Liu and Penner, 2005] has been implemented in an aerosol-enabled multi-scale modeling framework (PNNL MMF) to study ice formation in upper troposphere cirrus clouds through both homogeneous and heterogeneous nucleation. The MMF model represents cloud scale processes by embedding a cloud-resolving model (CRM) within each vertical column of a GCM grid. By explicitly linking ice nucleation to aerosol number concentration, CRM-scale temperature, relative humidity and vertical velocity, the new MMF model simulates the persistent high ice supersaturation and low ice number concentration (10 to 100/L) at cirrus temperatures. The low ice numbermore » is attributed to the dominance of heterogeneous nucleation in ice formation. The new model simulates the observed shift of the ice supersaturation PDF towards higher values at low temperatures following homogeneous nucleation threshold. The MMF models predict a higher frequency of midlatitude supersaturation in the Southern hemisphere and winter hemisphere, which is consistent with previous satellite and in-situ observations. It is shown that compared to a conventional GCM, the MMF is a more powerful model to emulate parameters that evolve over short time scales such as supersaturation. Sensitivity tests suggest that the simulated global distribution of ice clouds is sensitive to the ice nucleation schemes and the distribution of sulfate and dust aerosols. Simulations are also performed to test empirical parameters related to auto-conversion of ice crystals to snow. Results show that with a value of 250 μm for the critical diameter, Dcs, that distinguishes ice crystals from snow, the model can produce good agreement to the satellite retrieved products in terms of cloud ice water path and ice water content, while the total ice water is not sensitive to the specification of Dcs value.« less

  13. Investigating ice nucleation in cirrus clouds with an aerosol-enabled Multiscale Modeling Framework

    SciTech Connect (OSTI)

    Zhang, Chengzhu; Wang, Minghuai; Morrison, H.; Somerville, Richard C.; Zhang, Kai; Liu, Xiaohong; Li, J-L F.

    2014-12-01

    In this study, an aerosol-dependent ice nucleation scheme [Liu and Penner, 2005] has been implemented in an aerosol-enabled multi-scale modeling framework (PNNL MMF) to study ice formation in upper troposphere cirrus clouds through both homogeneous and heterogeneous nucleation. The MMF model represents cloud scale processes by embedding a cloud-resolving model (CRM) within each vertical column of a GCM grid. By explicitly linking ice nucleation to aerosol number concentration, CRM-scale temperature, relative humidity and vertical velocity, the new MMF model simulates the persistent high ice supersaturation and low ice number concentration (10 to 100/L) at cirrus temperatures. The low ice number is attributed to the dominance of heterogeneous nucleation in ice formation. The new model simulates the observed shift of the ice supersaturation PDF towards higher values at low temperatures following homogeneous nucleation threshold. The MMF models predict a higher frequency of midlatitude supersaturation in the Southern hemisphere and winter hemisphere, which is consistent with previous satellite and in-situ observations. It is shown that compared to a conventional GCM, the MMF is a more powerful model to emulate parameters that evolve over short time scales such as supersaturation. Sensitivity tests suggest that the simulated global distribution of ice clouds is sensitive to the ice nucleation schemes and the distribution of sulfate and dust aerosols. Simulations are also performed to test empirical parameters related to auto-conversion of ice crystals to snow. Results show that with a value of 250 ?m for the critical diameter, Dcs, that distinguishes ice crystals from snow, the model can produce good agreement to the satellite retrieved products in terms of cloud ice water path and ice water content, while the total ice water is not sensitive to the specification of Dcs value.

  14. Investigating ice nucleation in cirrus clouds with an aerosol-enabled Multiscale Modeling Framework

    SciTech Connect (OSTI)

    Zhang, Chengzhu; Wang, Minghuai; Morrison, H.; Somerville, Richard C.; Zhang, Kai; Liu, Xiaohong; Li, J-L F.

    2014-11-06

    In this study, an aerosol-dependent ice nucleation scheme [Liu and Penner, 2005] has been implemented in an aerosol-enabled multi-scale modeling framework (PNNL MMF) to study ice formation in upper troposphere cirrus clouds through both homogeneous and heterogeneous nucleation. The MMF model represents cloud scale processes by embedding a cloud-resolving model (CRM) within each vertical column of a GCM grid. By explicitly linking ice nucleation to aerosol number concentration, CRM-scale temperature, relative humidity and vertical velocity, the new MMF model simulates the persistent high ice supersaturation and low ice number concentration (10 to 100/L) at cirrus temperatures. The low ice number is attributed to the dominance of heterogeneous nucleation in ice formation. The new model simulates the observed shift of the ice supersaturation PDF towards higher values at low temperatures following homogeneous nucleation threshold. The MMF models predict a higher frequency of midlatitude supersaturation in the Southern hemisphere and winter hemisphere, which is consistent with previous satellite and in-situ observations. It is shown that compared to a conventional GCM, the MMF is a more powerful model to emulate parameters that evolve over short time scales such as supersaturation. Sensitivity tests suggest that the simulated global distribution of ice clouds is sensitive to the ice nucleation schemes and the distribution of sulfate and dust aerosols. Simulations are also performed to test empirical parameters related to auto-conversion of ice crystals to snow. Results show that with a value of 250 ?m for the critical diameter, Dcs, that distinguishes ice crystals from snow, the model can produce good agreement to the satellite retrieved products in terms of cloud ice water path and ice water content, while the total ice water is not sensitive to the specification of Dcs value.

  15. Improved Arctic Cloud and Aerosol Research and Model Parameterizations

    SciTech Connect (OSTI)

    Kenneth Sassen

    2007-03-01

    In this report are summarized our contributions to the Atmospheric Measurement (ARM) program supported by the Department of Energy. Our involvement commenced in 1990 during the planning stages of the design of the ARM Cloud and Radiation Testbed (CART) sites. We have worked continuously (up to 2006) on our ARM research objectives, building on our earlier findings to advance our knowledge in several areas. Below we summarize our research over this period, with an emphasis on the most recent work. We have participated in several aircraft-supported deployments at the SGP and NSA sites. In addition to deploying the Polarization Diversity Lidar (PDL) system (Sassen 1994; Noel and Sassen 2005) designed and constructed under ARM funding, we have operated other sophisticated instruments W-band polarimetric Doppler radar, and midinfrared radiometer for intercalibration and student training purposes. We have worked closely with University of North Dakota scientists, twice co-directing the Citation operations through ground-to-air communications, and serving as the CART ground-based mission coordinator with NASA aircraft during the 1996 SUCCESS/IOP campaign. We have also taken a leading role in initiating case study research involving a number of ARM coinvestigators. Analyses of several case studies from these IOPs have been reported in journal articles, as we show in Table 1. The PDL has also participated in other major field projects, including FIRE II and CRYSTAL-FACE. In general, the published results of our IOP research can be divided into two categories: comprehensive cloud case study analyses to shed light on fundamental cloud processes using the unique CART IOP measurement capabilities, and the analysis of in situ data for the testing of remote sensing cloud retrieval algorithms. One of the goals of the case study approach is to provide sufficiently detailed descriptions of cloud systems from the data-rich CART environment to make them suitable for application to

  16. Aerosol concentration and size distribution measured below, in, and above cloud from the DOE G-1 during VOCALS-REx

    SciTech Connect (OSTI)

    Kleinman, L.I.; Daum, P. H.; Lee, Y.-N.; Lewis, E. R.; Sedlacek III, A. J.; Senum, G. I.; Springston, S. R.; Wang, J.; Hubbe, J.; Jayne, J.; Min, Q.; Yum, S. S.; Allen, G.

    2011-06-21

    During the VOCALS Regional Experiment, the DOE G-1 aircraft was used to sample a varying aerosol environment pertinent to properties of stratocumulus clouds over a longitude band extending 800 km west from the Chilean coast at Arica. Trace gas and aerosol measurements are presented as a function of longitude, altitude, and dew point in this study. Spatial distributions are consistent with an upper atmospheric source for O{sub 3} and South American coastal sources for marine boundary layer (MBL) CO and aerosol, most of which is acidic sulfate in agreement with the dominant pollution source being SO{sub 2} from Cu smelters and power plants. Pollutant layers in the free troposphere (FT) can be a result of emissions to the north in Peru or long range transport from the west. At a given altitude in the FT (up to 3 km), dew point varies by 40 C with dry air descending from the upper atmospheric and moist air having a BL contribution. Ascent of BL air to a cold high altitude results in the condensation and precipitation removal of all but a few percent of BL water along with aerosol that served as CCN. Thus, aerosol volume decreases with dew point in the FT. Aerosol size spectra have a bimodal structure in the MBL and an intermediate diameter unimodal distribution in the FT. Comparing cloud droplet number concentration (CDNC) and pre-cloud aerosol (Dp > 100 nm) gives a linear relation up to a number concentration of {approx}150 cm{sup -3}, followed by a less than proportional increase in CDNC at higher aerosol number concentration. A number balance between below cloud aerosol and cloud droplets indicates that {approx}25% of aerosol in the PCASP size range are interstitial (not activated). One hundred and two constant altitude cloud transects were identified and used to determine properties of interstitial aerosol. One transect is examined in detail as a case study. Approximately 25 to 50% of aerosol with D{sub p} > 110 nm were not activated, the difference between the two

  17. Lidar Investigations of Aerosol, Cloud, and Boundary Layer Properties Over the ARM ACRF Sites

    SciTech Connect (OSTI)

    Turner, David D.; Ferrare, Richard

    2015-01-13

    The systematic and routine measurements of aerosol, water vapor, and clouds in the vertical column above the Atmospheric Radiation Measurement (ARM) sites from surface-based remote sensing systems provides a unique and comprehensive data source that can be used to characterize the boundary layer (i.e., the lowest 3 km of the atmosphere) and its evolution. New algorithms have been developed to provide critical datasets from ARM instruments, and these datasets have been used in long-term analyses to better understand the climatology of water vapor and aerosol over Darwin, the turbulent structure of the boundary layer and its statistical properties over Oklahoma, and to better determine the distribution of ice and aerosol particles over northern Alaska.

  18. Global Distribution and Climate Forcing of Marine Organic Aerosol - Part 2: Effects on Cloud Properties and Radiative Forcing

    SciTech Connect (OSTI)

    Gantt, Brett; Xu, Jun; Meskhidze, N.; Zhang, Yang; Nenes, Athanasios; Ghan, Steven J.; Liu, Xiaohong; Easter, Richard C.; Zaveri, Rahul A.

    2012-07-25

    A series of simulations with the Community Atmosphere Model version 5 (CAM5) with a 7-mode Modal Aerosol Model were conducted to assess the changes in cloud microphysical properties and radiative forcing resulting from marine organic aerosols. Model simulations show that the anthropogenic aerosol indirect forcing (AIF) predicted by CAM5 is decreased in absolute magnitude by up to 0.09 Wm{sup -2} (7 %) when marine organic aerosols are included. Changes in the AIF from marine organic aerosols are associated with small global increases in low-level incloud droplet number concentration and liquid water path of 1.3 cm{sup -3} (1.5 %) and 0.22 gm{sup -2} (0.5 %), respectively. Areas especially sensitive to changes in cloud properties due to marine organic aerosol include the Southern Ocean, North Pacific Ocean, and North Atlantic Ocean, all of which are characterized by high marine organic emission rates. As climate models are particularly sensitive to the background aerosol concentration, this small but non-negligible change in the AIF due to marine organic aerosols provides a notable link for ocean-ecosystem marine low-level cloud interactions and may be a candidate for consideration in future earth system models.

  19. Aerosol, Cloud, and Climate: From Observation to Model (457th Brookhaven Lecture)

    ScienceCinema (OSTI)

    Wang, Jian [Ph.D., Environmental Sciences Department

    2010-09-01

    In the last 100 years, the Earth has warmed by about 1ºF, glaciers and sea ice have been melting more quickly than previously, especially during the past decade, and the level of the sea has risen about 6-8 inches worldwide. Scientists have long been investigating this phenomenon of ?global warming,? which is believed to be at least partly due to the increased carbon dioxide (CO2) concentration in the air from burning fossil fuels. Funded by DOE, teams of researchers from BNL and other national labs have been gathering data in the U.S. and internationally to build computer models of climate and weather to help in understanding general patterns, causes, and perhaps, solutions. Among many findings, researchers observed that atmospheric aerosols, minute particles in the atmosphere, can significantly affect global energy balance and climate. Directly, aerosols scatter and absorb sunlight. Indirectly, increased aerosol concentration can lead to smaller cloud droplets, changing clouds in ways that tend to cool global climate and potentially mask overall warming from man-made CO2.

  20. Aerosol, Cloud, and Climate: From Observation to Model (457th Brookhaven Lecture)

    SciTech Connect (OSTI)

    Wang, Jian

    2010-05-12

    In the last 100 years, the Earth has warmed by about 1F, glaciers and sea ice have been melting more quickly than previously, especially during the past decade, and the level of the sea has risen about 6-8 inches worldwide. Scientists have long been investigating this phenomenon of global warming, which is believed to be at least partly due to the increased carbon dioxide (CO2) concentration in the air from burning fossil fuels. Funded by DOE, teams of researchers from BNL and other national labs have been gathering data in the U.S. and internationally to build computer models of climate and weather to help in understanding general patterns, causes, and perhaps, solutions. Among many findings, researchers observed that atmospheric aerosols, minute particles in the atmosphere, can significantly affect global energy balance and climate. Directly, aerosols scatter and absorb sunlight. Indirectly, increased aerosol concentration can lead to smaller cloud droplets, changing clouds in ways that tend to cool global climate and potentially mask overall warming from man-made CO2.

  1. Determining Best Estimates and Uncertainties in Cloud Microphysical Parameters from ARM Field Data: Implications for Models, Retrieval Schemes and Aerosol-Cloud-Radiation Interactions

    SciTech Connect (OSTI)

    McFarquhar, Greg

    2015-12-28

    We proposed to analyze in-situ cloud data collected during ARM/ASR field campaigns to create databases of cloud microphysical properties and their uncertainties as needed for the development of improved cloud parameterizations for models and remote sensing retrievals, and for evaluation of model simulations and retrievals. In particular, we proposed to analyze data collected over the Southern Great Plains (SGP) during the Mid-latitude Continental Convective Clouds Experiment (MC3E), the Storm Peak Laboratory Cloud Property Validation Experiment (STORMVEX), the Small Particles in Cirrus (SPARTICUS) Experiment and the Routine AAF Clouds with Low Optical Water Depths (CLOWD) Optical Radiative Observations (RACORO) field campaign, over the North Slope of Alaska during the Indirect and Semi-Direct Aerosol Campaign (ISDAC) and the Mixed-Phase Arctic Cloud Experiment (M-PACE), and over the Tropical Western Pacific (TWP) during The Tropical Warm Pool International Cloud Experiment (TWP-ICE), to meet the following 3 objectives; derive statistical databases of single ice particle properties (aspect ratio AR, dominant habit, mass, projected area) and distributions of ice crystals (size distributions SDs, mass-dimension m-D, area-dimension A-D relations, mass-weighted fall speeds, single-scattering properties, total concentrations N, ice mass contents IWC), complete with uncertainty estimates; assess processes by which aerosols modulate cloud properties in arctic stratus and mid-latitude cumuli, and quantify aerosol’s influence in context of varying meteorological and surface conditions; and determine how ice cloud microphysical, single-scattering and fall-out properties and contributions of small ice crystals to such properties vary according to location, environment, surface, meteorological and aerosol conditions, and develop parameterizations of such effects.In this report we describe the accomplishments that we made on all 3 research objectives.

  2. Global and regional modeling of clouds and aerosols in the marine boundary layer during VOCALS: the VOCA intercomparison

    SciTech Connect (OSTI)

    Wyant, M. C.; Bretherton, Christopher S.; Wood, Robert; Carmichael, Gregory; Clarke, A. D.; Fast, Jerome D.; George, R.; Gustafson, William I.; Hannay, Cecile; Lauer, Axel; Lin, Yanluan; Morcrette, J. -J.; Mulcahay, Jane; Saide, Pablo; Spak, S. N.; Yang, Qing

    2015-01-09

    A diverse collection of models are used to simulate the marine boundary layer in the southeast Pacific region during the period of the October–November 2008 VOCALS REx (VAMOS Ocean Cloud Atmosphere Land Study Regional Experiment) field campaign. Regional models simulate the period continuously in boundary-forced free-running mode, while global forecast models and GCMs (general circulation models) are run in forecast mode. The models are compared to extensive observations along a line at 20° S extending westward from the South American coast. Most of the models simulate cloud and aerosol characteristics and gradients across the region that are recognizably similar to observations, despite the complex interaction of processes involved in the problem, many of which are parameterized or poorly resolved. Some models simulate the regional low cloud cover well, though many models underestimate MBL (marine boundary layer) depth near the coast. Most models qualitatively simulate the observed offshore gradients of SO2, sulfate aerosol, CCN (cloud condensation nuclei) concentration in the MBL as well as differences in concentration between the MBL and the free troposphere. Most models also qualitatively capture the decrease in cloud droplet number away from the coast. However, there are large quantitative intermodel differences in both means and gradients of these quantities. Many models are able to represent episodic offshore increases in cloud droplet number and aerosol concentrations associated with periods of offshore flow. Most models underestimate CCN (at 0.1% supersaturation) in the MBL and free troposphere. The GCMs also have difficulty simulating coastal gradients in CCN and cloud droplet number concentration near the coast. The overall performance of the models demonstrates their potential utility in simulating aerosol–cloud interactions in the MBL, though quantitative estimation of aerosol–cloud interactions and aerosol indirect effects of MBL

  3. Global and regional modeling of clouds and aerosols in the marine boundary layer during VOCALS: the VOCA intercomparison

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Wyant, M. C.; Bretherton, Christopher S.; Wood, Robert; Carmichael, Gregory; Clarke, A. D.; Fast, Jerome D.; George, R.; Gustafson, William I.; Hannay, Cecile; Lauer, Axel; et al

    2015-01-09

    A diverse collection of models are used to simulate the marine boundary layer in the southeast Pacific region during the period of the October–November 2008 VOCALS REx (VAMOS Ocean Cloud Atmosphere Land Study Regional Experiment) field campaign. Regional models simulate the period continuously in boundary-forced free-running mode, while global forecast models and GCMs (general circulation models) are run in forecast mode. The models are compared to extensive observations along a line at 20° S extending westward from the South American coast. Most of the models simulate cloud and aerosol characteristics and gradients across the region that are recognizably similar tomore » observations, despite the complex interaction of processes involved in the problem, many of which are parameterized or poorly resolved. Some models simulate the regional low cloud cover well, though many models underestimate MBL (marine boundary layer) depth near the coast. Most models qualitatively simulate the observed offshore gradients of SO2, sulfate aerosol, CCN (cloud condensation nuclei) concentration in the MBL as well as differences in concentration between the MBL and the free troposphere. Most models also qualitatively capture the decrease in cloud droplet number away from the coast. However, there are large quantitative intermodel differences in both means and gradients of these quantities. Many models are able to represent episodic offshore increases in cloud droplet number and aerosol concentrations associated with periods of offshore flow. Most models underestimate CCN (at 0.1% supersaturation) in the MBL and free troposphere. The GCMs also have difficulty simulating coastal gradients in CCN and cloud droplet number concentration near the coast. The overall performance of the models demonstrates their potential utility in simulating aerosol–cloud interactions in the MBL, though quantitative estimation of aerosol–cloud interactions and aerosol indirect effects of MBL clouds

  4. ARM - 2016 AMS Ninth Symposium on Aerosol-Cloud-Climate Interactions

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Abstracts Ninth Symposium on Aerosol-Cloud-Climate Interactions Abstracts Media Contact Hanna Goss hanna-dot-goss-at-pnnl-dot-gov @armnewsteam Field Notes Blog Topics Field Notes117 AGU 3 AMIE 10 ARM Aerial Facility 2 ARM Mobile Facility 1 7 ARM Mobile Facility 2 47 ARM Mobile Facility 3 1 BAECC 1 BBOP 4 CARES 1 Data Quality Office 2 ENA 2 GOAMAZON 7 HI-SCALE 4 LASIC 3 MAGIC 15 MC3E 17 PECAN 3 SGP 8 STORMVEX 29 TCAP 3 Search News Search Blog News Center All Categories What's this? Social

  5. Chemical and physical influences on aerosol activation in liquid clouds: a study based on observations from the Jungfraujoch, Switzerland

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Hoyle, Christopher R.; Webster, Clare S.; Rieder, Harald E.; Nenes, Athanasios; Hammer, Emanuel; Herrmann, Erik; Gysel, Martin; Bukowiecki, Nicolas; Weingartner, Ernest; Steinbacher, Martin; et al

    2016-03-29

    In this study, a simple statistical model to predict the number of aerosols which activate to form cloud droplets in warm clouds has been established, based on regression analysis of data from four summertime Cloud and Aerosol Characterisation Experiments (CLACE) at the high-altitude site Jungfraujoch (JFJ). It is shown that 79 % of the observed variance in droplet numbers can be represented by a model accounting only for the number of potential cloud condensation nuclei (defined as number of particles larger than 80 nm in diameter), while the mean errors in the model representation may be reduced by the additionmore » of further explanatory variables, such as the mixing ratios of O3, CO, and the height of the measurements above cloud base. The statistical model has a similar ability to represent the observed droplet numbers in each of the individual years, as well as for the two predominant local wind directions at the JFJ (northwest and southeast). Given the central European location of the JFJ, with air masses in summer being representative of the free troposphere with regular boundary layer in-mixing via convection, we expect that this statistical model is generally applicable to warm clouds under conditions where droplet formation is aerosol limited (i.e. at relatively high updraught velocities and/or relatively low aerosol number concentrations). Finally, a comparison between the statistical model and an established microphysical parametrization shows good agreement between the two and supports the conclusion that cloud droplet formation at the JFJ is predominantly controlled by the number concentration of aerosol particles.« less

  6. CLOUDS, AEROSOLS, RADIATION AND THE AIR-SEA INTERFACE OF THE SOUTHERN OCEAN: ESTABLISHING DIRECTIONS FOR FUTURE RESEARCH

    SciTech Connect (OSTI)

    Wood, Robert; Bretherton, Chris; McFarquhar, Greg; Protat, Alain; Quinn, Patricia; Siems, Steven; Jakob, Christian; Alexander, Simon; Weller, Bob

    2014-09-29

    A workshop sponsored by the Department of Energy was convened at the University of Washington to discuss the state of knowledge of clouds, aerosols and air-sea interaction over the Southern Ocean and to identify strategies for reducing uncertainties in their representation in global and regional models. The Southern Ocean plays a critical role in the global climate system and is a unique pristine environment, yet other than from satellite, there have been sparse observations of clouds, aerosols, radiation and the air-sea interface in this region. Consequently, much is unknown about atmospheric and oceanographic processes and their linkage in this region. Approximately 60 scientists, including graduate students, postdoctoral fellows and senior researchers working in atmospheric and oceanic sciences at U.S. and foreign universities and government laboratories, attended the Southern Ocean Workshop. It began with a day of scientific talks, partly in plenary and partly in two parallel sessions, discussing the current state of the science for clouds, aerosols and air-sea interaction in the Southern Ocean. After the talks, attendees broke into two working groups; one focused on clouds and meteorology, and one focused on aerosols and their interactions with clouds. This was followed by more plenary discussion to synthesize the two working group discussions and to consider possible plans for organized activities to study clouds, aerosols and the air-sea interface in the Southern Ocean. The agenda and talk slides, including short summaries of the highlights of the parallel session talks developed by the session chars, are available at http://www.atmos.washington.edu/socrates/presentations/SouthernOceanPresentations/.

  7. Improvement in Clouds and the Earth's Radiant Energy System/Surface and Atmosphere Radiation Budget Dust Aerosol Properties, Effects on Surface Validation of Clouds and Radiative Swath

    SciTech Connect (OSTI)

    Rutan, D.; Rose, F.; Charlock, T.P.

    2005-03-18

    Within the Clouds and the Earth's Radiant Energy System (CERES) science team (Wielicki et al. 1996), the Surface and Atmospheric Radiation Budget (SARB) group is tasked with calculating vertical profiles of heating rates, globally, and continuously, beneath CERES footprint observations of Top of Atmosphere (TOA) fluxes. This is accomplished using a fast radiative transfer code originally developed by Qiang Fu and Kuo-Nan Liou (Fu and Liou 1993) and subsequently highly modified by the SARB team. Details on the code and its inputs can be found in Kato et al. (2005) and Rose and Charlock (2002). Among the many required inputs is characterization of the vertical column profile of aerosols beneath each footprint. To do this SARB combines aerosol optical depth information from the moderate-resolution imaging spectroradiometer (MODIS) instrument along with aerosol constituents specified by the Model for Atmosphere and Chemical Transport (MATCH) of Collins et al. (2001), and aerosol properties (e.g. single scatter albedo and asymmetry parameter) from Tegen and Lacis (1996) and OPAC (Hess et al. 1998). The publicly available files that include these flux profiles, called the Clouds and Radiative Swath (CRS) data product, available from the Langley Atmospheric Sciences Data Center (http://eosweb.larc.nasa.gov/). As various versions of the code are completed, publishable results are named ''Editions.'' After CRS Edition 2A was finalized it was found that dust aerosols were too absorptive. Dust aerosols have subsequently been modified using a new set of properties developed by Andy Lacis and results have been released in CRS Edition 2B. This paper discusses the effects of changing desert dust aerosol properties, which can be significant for the radiation budget in mid ocean, a few thousand kilometers from the source regions. Resulting changes are validated via comparison of surface observed fluxes from the Saudi Solar Village surface site (Myers et al. 1999), and the E13 site

  8. ARM - PI Product - Cloud Property Retrieval Products for Graciosa Island,

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Azores ProductsCloud Property Retrieval Products for Graciosa Island, Azores ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send PI Product : Cloud Property Retrieval Products for Graciosa Island, Azores [ research data - ASR funded ] The motivation for developing this product was to use the Dong et al. 1998 method to retrieve cloud microphysical properties, such as cloud droplet effective radius, cloud droplets

  9. Saharan dust as a causal factor of hemispheric asymmetry in aerosols and cloud cover over the tropical Atlantic Ocean

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Kishcha, Pavel; Da Sliva, Arlindo; Starobinets, Boris; Long, Charles N.; Kalashnikova, Olga; Alpert, Pinhas

    2015-07-09

    Meridional distribution of aerosol optical thickness (AOT) over the tropical Atlantic Ocean (30°N – 30°S) was analyzed to assess seasonal variations of meridional AOT asymmetry. Ten-year MERRA Aerosol Reanalysis (MERRAero) data (July 2002 – June 2012) confirms that the Sahara desert emits a significant amount of dust into the atmosphere over the Atlantic Ocean. Only over the Atlantic Ocean did MERRAero show that desert dust dominates other aerosol species and is responsible for meridional aerosol asymmetry between the tropical North and South Atlantic. Over the 10-year period under consideration, both MISR measurements and MERRAero data showed a pronounced meridional AOTmore » asymmetry. The meridional AOT asymmetry, characterized by the hemispheric ratio (RAOT) of AOT averaged separately over the North and over the South Atlantic, was about 1.7. Seasonally, meridional AOT asymmetry over the Atlantic was the most pronounced between March and July, when dust presence is maximal (RAOT ranged from 2 to 2.4). There was no noticeable meridional aerosol asymmetry in total AOT from September to October. During this period the contribution of carbonaceous aerosols to total AOT in the South Atlantic was comparable to the contribution of dust aerosols to total AOT in the North Atlantic. During the same 10-year period, MODIS cloud fraction (CF) data showed that there was no noticeable asymmetry in meridional CF distribution in different seasons (the hemispheric ratio of CF ranged from 1.0 to 1.2). MODIS CF data illustrated significant cloud cover (CF of 0.7 – 0.9) with limited precipitation ability along the Saharan Air Layer.« less

  10. Saharan dust as a causal factor of hemispheric asymmetry in aerosols and cloud cover over the tropical Atlantic Ocean

    SciTech Connect (OSTI)

    Kishcha, Pavel; Da Sliva, Arlindo; Starobinets, Boris; Long, Charles N.; Kalashnikova, Olga; Alpert, Pinhas

    2015-07-09

    Meridional distribution of aerosol optical thickness (AOT) over the tropical Atlantic Ocean (30°N – 30°S) was analyzed to assess seasonal variations of meridional AOT asymmetry. Ten-year MERRA Aerosol Reanalysis (MERRAero) data (July 2002 – June 2012) confirms that the Sahara desert emits a significant amount of dust into the atmosphere over the Atlantic Ocean. Only over the Atlantic Ocean did MERRAero show that desert dust dominates other aerosol species and is responsible for meridional aerosol asymmetry between the tropical North and South Atlantic. Over the 10-year period under consideration, both MISR measurements and MERRAero data showed a pronounced meridional AOT asymmetry. The meridional AOT asymmetry, characterized by the hemispheric ratio (RAOT) of AOT averaged separately over the North and over the South Atlantic, was about 1.7. Seasonally, meridional AOT asymmetry over the Atlantic was the most pronounced between March and July, when dust presence is maximal (RAOT ranged from 2 to 2.4). There was no noticeable meridional aerosol asymmetry in total AOT from September to October. During this period the contribution of carbonaceous aerosols to total AOT in the South Atlantic was comparable to the contribution of dust aerosols to total AOT in the North Atlantic. During the same 10-year period, MODIS cloud fraction (CF) data showed that there was no noticeable asymmetry in meridional CF distribution in different seasons (the hemispheric ratio of CF ranged from 1.0 to 1.2). MODIS CF data illustrated significant cloud cover (CF of 0.7 – 0.9) with limited precipitation ability along the Saharan Air Layer.

  11. A New Approach to Modeling Aerosol Effects on East Asian Climate: Parametric Uncertainties Associated with Emissions, Cloud Microphysics and their Interactions

    SciTech Connect (OSTI)

    Yan, Huiping; Qian, Yun; Zhao, Chun; Wang, Hailong; Wang, Minghuai; Yang, Ben; Liu, Xiaohong; Fu, Qiang

    2015-09-16

    In this study, we adopt a parametric sensitivity analysis framework that integrates the quasi-Monte Carlo parameter sampling approach and a surrogate model to examine aerosol effects on the East Asian Monsoon climate simulated in the Community Atmosphere Model (CAM5). A total number of 256 CAM5 simulations are conducted to quantify the model responses to the uncertain parameters associated with cloud microphysics parameterizations and aerosol (e.g., sulfate, black carbon (BC), and dust) emission factors and their interactions. Results show that the interaction terms among parameters are important for quantifying the sensitivity of fields of interest, especially precipitation, to the parameters. The relative importance of cloud-microphysics parameters and emission factors (strength) depends on evaluation metrics or the model fields we focused on, and the presence of uncertainty in cloud microphysics imposes an additional challenge in quantifying the impact of aerosols on cloud and climate. Due to their different optical and microphysical properties and spatial distributions, sulfate, BC, and dust aerosols have very different impacts on East Asian Monsoon through aerosol-cloud-radiation interactions. The climatic effects of aerosol do not always have a monotonic response to the change of emission factors. The spatial patterns of both sign and magnitude of aerosol-induced changes in radiative fluxes, cloud, and precipitation could be different, depending on the aerosol types, when parameters are sampled in different ranges of values. We also identify the different cloud microphysical parameters that show the most significant impact on climatic effect induced by sulfate, BC and dust, respectively, in East Asia.

  12. A new WRF-Chem treatment for studying regional-scale impacts of cloud processes on aerosol and trace gases in parameterized cumuli

    SciTech Connect (OSTI)

    Berg, L. K.; Shrivastava, M.; Easter, R. C.; Fast, J. D.; Chapman, E. G.; Liu, Y.; Ferrare, R. A.

    2015-02-24

    A new treatment of cloud effects on aerosol and trace gases within parameterized shallow and deep convection, and aerosol effects on cloud droplet number, has been implemented in the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) version 3.2.1 that can be used to better understand the aerosol life cycle over regional to synoptic scales. The modifications to the model include treatment of the cloud droplet number mixing ratio; key cloud microphysical and macrophysical parameters (including the updraft fractional area, updraft and downdraft mass fluxes, and entrainment) averaged over the population of shallow clouds, or a single deep convective cloud; and vertical transport, activation/resuspension, aqueous chemistry, and wet removal of aerosol and trace gases in warm clouds. These changes have been implemented in both the WRF-Chem chemistry packages as well as the Kain–Fritsch (KF) cumulus parameterization that has been modified to better represent shallow convective clouds. Testing of the modified WRF-Chem has been completed using observations from the Cumulus Humilis Aerosol Processing Study (CHAPS). The simulation results are used to investigate the impact of cloud–aerosol interactions on regional-scale transport of black carbon (BC), organic aerosol (OA), and sulfate aerosol. Based on the simulations presented here, changes in the column-integrated BC can be as large as –50% when cloud–aerosol interactions are considered (due largely to wet removal), or as large as +40% for sulfate under non-precipitating conditions due to sulfate production in the parameterized clouds. The modifications to WRF-Chem are found to account for changes in the cloud droplet number concentration (CDNC) and changes in the chemical composition of cloud droplet residuals in a way that is consistent with observations collected during CHAPS. Efforts are currently underway to port the changes described here to the latest version of WRF-Chem, and it is

  13. A new WRF-Chem treatment for studying regional-scale impacts of cloud processes on aerosol and trace gases in parameterized cumuli

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Berg, L. K.; Shrivastava, M.; Easter, R. C.; Fast, J. D.; Chapman, E. G.; Liu, Y.; Ferrare, R. A.

    2015-02-24

    A new treatment of cloud effects on aerosol and trace gases within parameterized shallow and deep convection, and aerosol effects on cloud droplet number, has been implemented in the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) version 3.2.1 that can be used to better understand the aerosol life cycle over regional to synoptic scales. The modifications to the model include treatment of the cloud droplet number mixing ratio; key cloud microphysical and macrophysical parameters (including the updraft fractional area, updraft and downdraft mass fluxes, and entrainment) averaged over the population of shallow clouds, or a single deep convectivemore » cloud; and vertical transport, activation/resuspension, aqueous chemistry, and wet removal of aerosol and trace gases in warm clouds. These changes have been implemented in both the WRF-Chem chemistry packages as well as the Kain–Fritsch (KF) cumulus parameterization that has been modified to better represent shallow convective clouds. Testing of the modified WRF-Chem has been completed using observations from the Cumulus Humilis Aerosol Processing Study (CHAPS). The simulation results are used to investigate the impact of cloud–aerosol interactions on regional-scale transport of black carbon (BC), organic aerosol (OA), and sulfate aerosol. Based on the simulations presented here, changes in the column-integrated BC can be as large as –50% when cloud–aerosol interactions are considered (due largely to wet removal), or as large as +40% for sulfate under non-precipitating conditions due to sulfate production in the parameterized clouds. The modifications to WRF-Chem are found to account for changes in the cloud droplet number concentration (CDNC) and changes in the chemical composition of cloud droplet residuals in a way that is consistent with observations collected during CHAPS. Efforts are currently underway to port the changes described here to the latest version of WRF-Chem, and it

  14. ARM - Midlatitude Continental Convective Clouds - Ultra High Sensitivity Aerosol Spectrometer(tomlinson-uhsas)

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Tomlinson, Jason; Jensen, Mike

    2012-02-28

    Ultra High Sensitivity Aerosol Spectrometer (UHSASA) A major component of the Mid-latitude Continental Convective Clouds Experiment (MC3E) field campaign was the deployment of an enhanced radiosonde array designed to capture the vertical profile of atmospheric state variables (pressure, temperature, humidity wind speed and wind direction) for the purpose of deriving the large-scale forcing for use in modeling studies. The radiosonde array included six sites (enhanced Central Facility [CF-1] plus five new sites) launching radiosondes at 3-6 hour sampling intervals. The network will cover an area of approximately (300)2 km2 with five outer sounding launch sites and one central launch location. The five outer sounding launch sites are: S01 Pratt, KS [ 37.7oN, 98.75oW]; S02 Chanute, KS [37.674, 95.488]; S03 Vici, Oklahoma [36.071, -99.204]; S04 Morris, Oklahoma [35.687, -95.856]; and S05 Purcell, Oklahoma [34.985, -97.522]. Soundings from the SGP Central Facility during MC3E can be retrieved from the regular ARM archive. During routine MC3E operations 4 radiosondes were launched from each of these sites (approx. 0130, 0730, 1330 and 1930 UTC). On days that were forecast to be convective up to four additional launches were launched at each site (approx. 0430, 1030, 1630, 2230 UTC). There were a total of approximately 14 of these high frequency launch days over the course of the experiment. These files contain brightness temperatures observed at Purcell during MC3E. The measurements were made with a 5 channel (22.235, 23.035, 23.835, 26.235, 30.000GHz) microwave radiometer at one minute intervals. The results have been separated into daily files and the day of observations is indicated in the file name. All observations were zenith pointing. Included in the files are the time variables base_time and time_offset. These follow the ARM time conventions. Base_time is the number seconds since January 1, 1970 at 00:00:00 for the first data point of the file and time_offset is

  15. An Audio-Magnetotelluric Investigation In Terceira Island (Azores...

    Open Energy Info (EERE)

    Audio-Magnetotelluric Investigation In Terceira Island (Azores) Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: An Audio-Magnetotelluric...

  16. Chemical aging of single and multicomponent biomass burning aerosol surrogate-particles by OH: implications for cloud condensation nucleus activity

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Slade, J. H.; Thalman, R.; Wang, J.; Knopf, D. A.

    2015-03-06

    Multiphase OH and O3 oxidation reactions with atmospheric organic aerosol (OA) can influence particle physicochemical properties including composition, morphology, and lifetime. Chemical aging of initially insoluble or low soluble single-component OA by OH and O3 can increase their water-solubility and hygroscopicity, making them more active as cloud condensation nuclei (CCN) and susceptible to wet deposition. However, an outstanding problem is whether the effects of chemical aging on their CCN activity are preserved when mixed with other organic or inorganic compounds exhibiting greater water-solubility. In this work, the CCN activity of laboratory-generated biomass burning aerosol (BBA) surrogate-particles exposed to OH andmore » O3 is evaluated by determining the hygroscopicity parameter, κ, as a function of particle type, mixing state, and OH/O3 exposure applying a CCN counter (CCNc) coupled to an aerosol flow reactor (AFR). Levoglucosan (LEV), 4-methyl-5-nitrocatechol (MNC), and potassium sulfate (KS) serve as representative BBA compounds that exhibit different hygroscopicity, water solubility, chemical functionalities, and reactivity with OH radicals, and thus exemplify the complexity of mixed inorganic/organic aerosol in the atmosphere. The CCN activities of all of the particles were unaffected by O3 exposure. Following exposure to OH, κ of MNC was enhanced by an order of magnitude, from 0.009 to ~0.1, indicating that chemically-aged MNC particles are better CCN and more prone to wet deposition than pure MNC particles. No significant enhancement in κ was observed for pure LEV particles following OH exposure. κ of the internally-mixed particles was not affected by OH oxidation. Furthermore, the CCN activity of OH exposed MNC-coated KS particles is similar to the OH unexposed atomized 1 : 1 by mass MNC : KS binary-component particles. Our results strongly suggest that when OA is dominated by water-soluble organic carbon (WSOC) or inorganic ions, chemical

  17. Chemical aging of single and multicomponent biomass burning aerosol surrogate particles by OH: implications for cloud condensation nucleus activity

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Slade, J. H.; Thalman, R.; Wang, J.; Knopf, D. A.

    2015-09-14

    Multiphase OH and O3 oxidation reactions with atmospheric organic aerosol (OA) can influence particle physicochemical properties including composition, morphology, and lifetime. Chemical aging of initially insoluble or low-soluble single-component OA by OH and O3 can increase their water solubility and hygroscopicity, making them more active as cloud condensation nuclei (CCN) and susceptible to wet deposition. However, an outstanding problem is whether the effects of chemical aging on their CCN activity are preserved when mixed with other organic or inorganic compounds exhibiting greater water solubility. In this work, the CCN activity of laboratory-generated biomass burning aerosol (BBA) surrogate particles exposed tomore » OH and O3 is evaluated by determining the hygroscopicity parameter, κ, as a function of particle type, mixing state, and OH and O3 exposure applying a CCN counter (CCNc) coupled to an aerosol flow reactor (AFR). Levoglucosan (LEV), 4-methyl-5-nitrocatechol (MNC), and potassium sulfate (KS) serve as representative BBA compounds that exhibit different hygroscopicity, water solubility, chemical functionalities, and reactivity with OH radicals, and thus exemplify the complexity of mixed inorganic/organic aerosol in the atmosphere. The CCN activities of all of the particles were unaffected by O3 exposure. Following exposure to OH, κ of MNC was enhanced by an order of magnitude, from 0.009 to ~ 0.1, indicating that chemically aged MNC particles are better CCN and more prone to wet deposition than pure MNC particles. No significant enhancement in κ was observed for pure LEV particles following OH exposure. κ of the internally mixed particles was not affected by OH oxidation. Furthermore, the CCN activity of OH-exposed MNC-coated KS particles is similar to the OH unexposed atomized 1 : 1 by mass MNC : KS binary-component particles. Our results strongly suggest that when OA is dominated by water-soluble organic carbon (WSOC) or inorganic ions

  18. Evaluation of aerosol-cloud interaction in the GISS ModelE using...

    Office of Scientific and Technical Information (OSTI)

    Sponsoring Org: USDOE SC OFFICE OF SCIENCE (SC) Country of Publication: United States Language: English Subject: 54 ENVIRONMENTAL SCIENCES Word Cloud More Like This Full Text ...

  19. Next generation aerosol-cloud microphysics for advanced high-resolution climate predictions

    SciTech Connect (OSTI)

    Bennartz, Ralf; Hamilton, Kevin P; Phillips, Vaughan T.J.; Wang, Yuqing; Brenguier, Jean-Louis

    2013-01-14

    The three top-level project goals are: -We proposed to develop, test, and run a new, physically based, scale-independent microphysical scheme for those cloud processes that most strongly affect greenhouse gas scenarios, i.e. warm cloud microphysics. In particular, we propsed to address cloud droplet activation, autoconversion, and accretion. -The new, unified scheme was proposed to be derived and tested using the University of Hawaii's IPRC Regional Atmospheric Model (iRAM). -The impact of the new parameterizations on climate change scenarios will be studied. In particular, the sensitivity of cloud response to climate forcing from increased greenhouse gas concentrations will be assessed.

  20. Aerosol Impacts on California Winter Clouds and Precipitation during CalWater 2011: Local Pollution versus Long-Range Transported Dust

    SciTech Connect (OSTI)

    Fan, Jiwen; Leung, Lai-Yung R.; DeMott, Paul J.; Comstock, Jennifer M.; Singh, Balwinder; Rosenfeld, Daniel; Tomlinson, Jason M.; White, Allen B.; Prather, Kimberly; Minnis, Patrick; Ayers, J. K.; Min, Qilong

    2014-01-03

    Mineral dust aerosols often observed over California in winter and spring, associated with long-range transport from Asia and Sahara, have been linked to enhanced precipitation based on observations. Local anthropogenic pollution, on the other hand, was shown in previous observational and modeling studies to reduce precipitation. Here we incorporate recent developments in ice nucleation parameterizations to link aerosols with ice crystal formation in a spectral-bin cloud microphysical model coupled with the Weather Research and Forecasting (WRF) model, to examine the relative and combined impacts of dust and local pollution particles on cloud properties and precipitation type and intensity. Simulations are carried out for two cloud cases with contrasting meteorology and cloud dynamics that occurred on February 16 (FEB16) and March 02 (MAR02) from the CalWater 2011 field campaign. In both cases, observations show the presence of dust and biological particles in a relative pristine environment. The simulated cloud microphysical properties and precipitation show reasonable agreement with aircraft and surface measurements. Model sensitivity experiments indicate that in the pristine environment, the dust and biological aerosol layers increase the accumulated precipitation by 10-20% from the Central Valley to the Sierra Nevada Mountains for both FEB16 and MAR02 due to a ~40% increase in snow formation, validating the observational hypothesis. Model results show that local pollution increases precipitation over the windward slope of the mountains by few percent due to increased snow formation when dust is present but reduces precipitation by 5-8% if dust is removed on FEB16. The effects of local pollution on cloud microphysics and precipitation strongly depend on meteorology including the strength of the Sierra Barrier Jet, and cloud dynamics. This study further underscores the importance of the interactions between local pollution, dust, and environmental conditions for

  1. Eastern North Atlantic Site, Graciosa Island, Azores

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    govSitesEastern North Atlantic ENA Related Links Facilities and Instruments ES&H Guidance Statement Operations Science Field Campaigns Visiting the Site ENA Fact Sheet (PDF, 512KB) Images Information for Guest Scientists Contacts Eastern North Atlantic This view shows Graciosa Island, Azores, Eastern North Atlantic Facility. Graciosa Island: 39° 5' 29.68" N, 28° 1' 32.34" W Altitude: 30.48 meters The new ENA observations site will be situated near the previous AMF deployment. The

  2. ARM - Measurement - Cloud condensation nuclei

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AOS : Aerosol Observing System CCN : Cloud Condensation Nuclei Particle Counter TDMA : Tandem Differential Mobility Analyzer Field Campaign Instruments AMT : Aerosol Modeling...

  3. ARM - Field Campaign - Measurement of Aerosols, Radiation and...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    the Southern Ocean Clouds Radiation Transport Aerosol Transport Experimental Study (SOCRATES) has been proposed to improve our understanding of clouds, aerosols, air-sea...

  4. Ground-based remote sensing scheme for monitoring aerosol–cloud interactions

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Sarna, Karolina; Russchenberg, Herman W. J.

    2016-03-14

    A new method for continuous observation of aerosol–cloud interactions with ground-based remote sensing instruments is presented. The main goal of this method is to enable the monitoring of the change of the cloud droplet size due to the change in the aerosol concentration. We use high-resolution measurements from a lidar, a radar and a radiometer, which allow us to collect and compare data continuously. This method is based on a standardised data format from Cloudnet and can be implemented at any observatory where the Cloudnet data set is available. Two example case studies were chosen from the Atmospheric Radiation Measurementmore » (ARM) Program deployment on Graciosa Island, Azores, Portugal, in 2009 to present the method. We use the cloud droplet effective radius (re) to represent cloud microphysical properties and an integrated value of the attenuated backscatter coefficient (ATB) below the cloud to represent the aerosol concentration. All data from each case study are divided into bins of the liquid water path (LWP), each 10 g m–2 wide. For every LWP bin we present the correlation coefficient between ln re and ln ATB, as well as ACIr (defined as ACIr = –d ln re/d ln ATB, change in cloud droplet effective radius with aerosol concentration). Obtained values of ACIr are in the range 0.01–0.1. Lastly, we show that ground-based remote sensing instruments used in synergy can efficiently and continuously monitor aerosol–cloud interactions.« less

  5. Aerosol transport and wet scavenging in deep convective clouds: a case study and model evaluation using a multiple passive tracer analysis approach

    SciTech Connect (OSTI)

    Yang, Qing; Easter, Richard C.; Campuzano-Jost, Pedro; Jimenez, Jose L.; Fast, Jerome D.; Ghan, Steven J.; Wang, Hailong; Berg, Larry K.; Barth, Mary; Liu, Ying; Shrivastava, ManishKumar B.; Singh, Balwinder; Morrison, H.; Fan, Jiwen; Ziegler, Conrad L.; Bela, Megan; Apel, Eric; Diskin, G. S.; Mikoviny, Tomas; Wisthaler, Armin

    2015-08-20

    The effect of wet scavenging on ambient aerosols in deep, continental convective clouds in the mid-latitudes is studied for a severe storm case in Oklahoma during the Deep Convective Clouds and Chemistry (DC3) field campaign. A new passive-tracer based transport analysis framework is developed to characterize the convective transport based on the vertical distribution of several slowly reacting and nearly insoluble trace gases. The passive gas concentration in the upper troposphere convective outflow results from a mixture of 47% from the lower level (0-3 km), 21% entrained from the upper troposphere, and 32% from mid-atmosphere based on observations. The transport analysis framework is applied to aerosols to estimate aerosol transport and wet-scavenging efficiency. Observations yield high overall scavenging efficiencies of 81% and 68% for aerosol mass (Dp < 1μm) and aerosol number (0.03< Dp < 2.5μm), respectively. Little chemical selectivity to wet scavenging is seen among observed submicron sulfate (84%), organic (82%), and ammonium (80%) aerosols, while nitrate has a much lower scavenging efficiency of 57% likely due to the uptake of nitric acid. Observed larger size particles (0.15 - 2.5μm) are scavenged more efficiently (84%) than smaller particles (64%; 0.03 - 0.15μm). The storm is simulated using the chemistry version of the WRF model. Compared to the observation based analysis, the standard model underestimates the wet scavenging efficiency for both mass and number concentrations with low biases of 31% and 40%, respectively. Adding a new treatment of secondary activation significantly improves simulation results, so that the bias in scavenging efficiency in mass and number concentrations is reduced to <10%. This supports the hypothesis that secondary activation is an important process for wet removal of aerosols in deep convective storms.

  6. Effective Radius of Cloud Droplets Derived from Ground-based...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    which could eventually facilitate aerosol-cloud interactions. (Kim, Klein, Norris, JGR, 2005) SD z (m) SD LWP (g m -2 ) Efficacy of Aerosol-Cloud Interactions - ...

  7. How do A-train Sensors Intercompare in the Retrieval of Above-Cloud Aerosol Optical Depth? A Case Study-based Assessment

    SciTech Connect (OSTI)

    Jethva, Hiren T.; Torres, Omar; Waquet, Fabien; Chand, Duli; Hu, Yong X.

    2014-01-15

    We inter-compare the above-cloud aerosol optical depth (ACAOD) of biomass burning plumes retrieved from different A-train sensors, i.e., MODIS, CALIOP, POLDER, and OMI. These sensors have shown independent capabilities to detect and retrieve aerosol loading above marine boundary layer clouds--a kind of situation often found over the Southeast Atlantic Ocean during dry burning season. A systematic one-to-one comparison reveals that, in general, all passive sensors and CALIOP-based research methods derive comparable ACAOD with differences mostly within 0.2 over homogeneous cloud fields. The 532-nm ACAOD retrieved by CALIOP operational algorithm is largely underestimated; however, it’s 1064-nm AOD when converted to 500 nm shows closer agreement to the passive sensors. Given the different types of sensor measurements processed with different algorithms, the close agreement between them is encouraging. Due to lack of adequate direct measurements above cloud, the validation of satellite-based ACAOD retrievals remains an open challenge. The inter-satellite comparison, however, can be useful for the relative evaluation and consistency check.

  8. ARM - Campaign Instrument - aerosol-tower-eml

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    (AEROSOL-TOWER-EML) Instrument Categories Aerosols Campaigns Remote Cloud Sensing (RCS) Field Evaluation Download Data Southern Great Plains, 1994.04.01 - 1994.05.31...

  9. Aerosol measurements at 60 m during April 1994 remote cloud study intensive operating period (RCS/IOP)

    SciTech Connect (OSTI)

    Leifer, R.; Albert, B.; Lee, N.; Knuth, R.H.

    1996-04-01

    Aerosol measurements were made at the Southern Great Plains Site of the Atmospheric Radiation Measurement (ARM) program. Many types of air masses pass over this area, and on the data acquisition day, extremly low aerosol scattering coefficients were seen. A major effort was placed on providing some characterization of the aerosol size distribution. Data is currently available from the experimental center.

  10. Cloud and aerosol characterization for the ARM central facility: Multiple remote sensor techniques development

    SciTech Connect (OSTI)

    Sassen, K.

    1992-04-30

    This research project designed to investigate how atmospheric remote sensing technology can best be applied to the characterization of the cloudy atmosphere. Our research program addresses basic atmospheric remote sensing questions, but at the same time is clearly directed toward providing information crucial to the ARM (Atmospheric Remote Sensing) program and for application to the Clouds and Radiation Testbed (CART). The instrumentation that is being brought into play includes a variety of art-of-the-art sensors. Available at NOAA WPL are polarization Doppler K{sub a}-band (0.86 mm) and X-band (3.2 cm) radars, a C0{sub 2}(10.6 {mu}m) Doppler lidar with sequential ' polarization measurement capabilities, a three-channel (20.6, 31.65 and 90 GHz) microwave radiometer, and variety of visible and infrared radiometers. Instrumentation at the University of Utah Facility for Atmospheric Remote Sensing (FARS) includes a polarization ruby (0.643 {mu}m) lidar, a narrow-beam (0.14{degree}) mid-infrared (9.5--11.5 {mu}m) radiometer coaligned with the lidar, several other radiometers in the visible and infrared spectral regions, and an advanced two-color (1.06 and 0.532 {mu}m), four-channel Polarization Diversity Lidar (PDL) and all-sky video imaging system that have only recently been developed under the ARM IDP.

  11. Vertical microphysical profiles of convective clouds as a tool for

    Office of Scientific and Technical Information (OSTI)

    obtaining aerosol cloud-mediated climate forcings (Technical Report) | SciTech Connect Vertical microphysical profiles of convective clouds as a tool for obtaining aerosol cloud-mediated climate forcings Citation Details In-Document Search Title: Vertical microphysical profiles of convective clouds as a tool for obtaining aerosol cloud-mediated climate forcings Quantifying the aerosol/cloud-mediated radiative effect at a global scale requires simultaneous satellite retrievals of cloud

  12. Aerosol Indirect Effect on the Grid-scale Clouds in the Two-way Coupled WRF-CMAQ: Model Description, Development, Evaluation and Regional Analysis

    SciTech Connect (OSTI)

    Yu, Shaocai; Mathur, Rohit; Pleim, Jonathan; Wong, David; Gilliam, R.; Alapaty, Kiran; Zhao, Chun; Liu, Xiaohong

    2014-10-24

    This study implemented first, second and glaciations aerosol indirect effects (AIE) on resolved clouds in the two-way coupled WRF-CMAQ modeling system by including parameterizations for both cloud drop and ice number concentrations on the basis of CMAQpredicted aerosol distributions and WRF meteorological conditions. The performance of the newly-developed WRF-CMAQ model, with alternate CAM and RRTMG radiation schemes, was evaluated with the observations from the CERES satellite and surface monitoring networks (AQS, IMPROVE, CASTNet, STN, and PRISM) over the continental U.S. (CONUS) (12-km resolution) and eastern Texas (4-km resolution) during August and September of 2006. The results at the AQS surface sites show that in August, the NMB values for PM2.5 over the eastern/western U.S (EUS/WUS) and western U.S. (WUS) are 5.3% (?0.1%) and 0.4% (-5.2%) for WRF-CMAQ/CAM (WRF-CMAQ/RRTMG), respectively. The evaluation of PM2.5 chemical composition reveals that in August, WRF-CMAQ/CAM (WRF-CMAQ/RRTMG) consistently underestimated the observed SO4 2? by -23.0% (-27.7%), -12.5% (-18.9%) and -7.9% (-14.8%) over the EUS at the CASTNet, IMPROVE and STN sites, respectively. Both models (WRF-CMAQ/CAM, WRF-CMAQ/RRTMG) overestimated the observed mean OC, EC and TC concentrations over the EUS in August at the IMPROVE sites. Both models generally underestimated the cloud field (SWCF) over the CONUS in August due to the fact that the AIE on the subgrid convective clouds was not considered when the model simulations were run at the 12 km resolution. This is in agreement with the fact that both models captured SWCF and LWCF very well for the 4-km simulation over the eastern Texas when all clouds were resolved by the finer domain. Both models generally overestimated the observed precipitation by more than 40% mainly because of significant overestimation in the southern part of the CONUS in August. The simulations of WRF-CMAQ/CAM and WRF-CMAQ/RRTMG show dramatic improvements for SWCF, LWCF

  13. The Indirect and Semi-Direct Aerosol Campaign

    SciTech Connect (OSTI)

    Ghan, Steve

    2014-03-24

    Research projects like the Indirect and Semi-Direct Aerosol Campaign, or ISDAC, increase our knowledge of atmospheric aerosol particles and cloud physics.

  14. The Indirect and Semi-Direct Aerosol Campaign

    ScienceCinema (OSTI)

    Ghan, Steve

    2014-06-12

    Research projects like the Indirect and Semi-Direct Aerosol Campaign, or ISDAC, increase our knowledge of atmospheric aerosol particles and cloud physics.

  15. Natural Aerosols Explain Seasonal and Spatial Patterns of Southern...

    Office of Scientific and Technical Information (OSTI)

    Natural Aerosols Explain Seasonal and Spatial Patterns of Southern Ocean Cloud Albedo Citation Details In-Document Search Title: Natural Aerosols Explain Seasonal and Spatial ...

  16. Discrimination between thin cirrus and and tropospheric aerosol...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Discrimination between thin cirrus and and tropospheric aerosol using multiple measurements from Darwin ARCS Mitchell, Ross CSIRO Category: Aerosols Thin cirrus cloud occurs...

  17. Studies of Emissions and Atmospheric Composition, Clouds, and...

    Office of Scientific and Technical Information (OSTI)

    and aerosols in deep convective outflow, and the influences and feedbacks of aerosol particles from anthropogenic pollution and biomass burning on meteorology, clouds, and climate. ...

  18. Final Technical Report for "Ice nuclei relation to aerosol properties: Data analysis and model parameterization for IN in mixed-phase clouds" (DOE/SC00002354)

    SciTech Connect (OSTI)

    Paul J. DeMott, Anthony J. Prenni; Sonia M. Kreidenweis

    2012-09-28

    Clouds play an important role in weather and climate. In addition to their key role in the hydrologic cycle, clouds scatter incoming solar radiation and trap infrared radiation from the surface and lower atmosphere. Despite their importance, feedbacks involving clouds remain as one of the largest sources of uncertainty in climate models. To better simulate cloud processes requires better characterization of cloud microphysical processes, which can affect the spatial extent, optical depth and lifetime of clouds. To this end, we developed a new parameterization to be used in numerical models that describes the variation of ice nuclei (IN) number concentrations active to form ice crystals in mixed-phase (water droplets and ice crystals co-existing) cloud conditions as these depend on existing aerosol properties and temperature. The parameterization is based on data collected using the Colorado State University continuous flow diffusion chamber in aircraft and ground-based campaigns over a 14-year period, including data from the DOE-supported Mixed-Phase Arctic Cloud Experiment. The resulting relationship is shown to more accurately represent the variability of ice nuclei distributions in the atmosphere compared to currently used parameterizations based on temperature alone. When implemented in one global climate model, the new parameterization predicted more realistic annually averaged cloud water and ice distributions, and cloud radiative properties, especially for sensitive higher latitude mixed-phase cloud regions. As a test of the new global IN scheme, it was compared to independent data collected during the 2008 DOE-sponsored Indirect and Semi-Direct Aerosol Campaign (ISDAC). Good agreement with this new data set suggests the broad applicability of the new scheme for describing general (non-chemically specific) aerosol influences on IN number concentrations feeding mixed-phase Arctic stratus clouds. Finally, the parameterization was implemented into a regional

  19. The Fertilizing Role of African Dust in the Amazon Rainforest. A First Multiyear Assessment Based on Data from Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations

    SciTech Connect (OSTI)

    Yu, Hongbin; Chin, Mian; Yuan, Tianle; Bian, Huisheng; Remer, L. A.; Prospero, J.; Omar, Ali; Winker, D.; Yang, Yuekui; Zhang, Yan; Zhang, Zhibo; Zhao, Chun

    2015-03-18

    The productivity of the Amazon rainforest is constrained by the availability of nutrients, in particular phosphorus (P). Deposition of long-range transported African dust is recognized as a potentially important but poorly quantified source of phosphorus. This study provides a first multiyear satellite-based estimate of dust deposition into the Amazon Basin using three dimensional (3D) aerosol measurements over 2007-2013 from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP). The 7-year average of dust deposition into the Amazon Basin is estimated to be 28 (8~48) Tg a-1 or 29 (8~50) kg ha-1 a-1. The dust deposition shows significant interannual variation that is negatively correlated with the prior-year rainfall in the Sahel. The CALIOP-based multi-year mean estimate of dust deposition matches better with estimates from in-situ measurements and model simulations than a previous satellite-based estimate does. The closer agreement benefits from a more realistic geographic definition of the Amazon Basin and inclusion of meridional dust transport calculation in addition to the 3D nature of CALIOP aerosol measurements. The imported dust could provide about 0.022 (0.006~0.037) Tg P of phosphorus per year, equivalent to 23 (7~39) g P ha-1 a-1 to fertilize the Amazon rainforest. This out-of-Basin P input is comparable to the hydrological loss of P from the Basin, suggesting an important role of African dust in preventing phosphorus depletion on time scales of decades to centuries.

  20. The dependence of cloud particle size and precipitation probability...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    effect Hongfei Shao and Guosheng Liu Meteorology Department, Florida State University INTRODUCTION INTRODUCTION Anthropogenic aerosols enhance cloud reflectance of solar...

  1. A Sensitivity Study of Radiative Fluxes at the Top of Atmosphere to Cloud-Microphysics and Aerosol Parameters in the Community Atmosphere Model CAM5

    SciTech Connect (OSTI)

    Zhao, Chun; Liu, Xiaohong; Qian, Yun; Yoon, Jin-Ho; Hou, Zhangshuan; Lin, Guang; McFarlane, Sally A.; Wang, Hailong; Yang, Ben; Ma, Po-Lun; Yan, Huiping; Bao, Jie

    2013-11-08

    In this study, we investigated the sensitivity of net radiative fluxes (FNET) at the top of atmosphere (TOA) to 16 selected uncertain parameters mainly related to the cloud microphysics and aerosol schemes in the Community Atmosphere Model version 5 (CAM5). We adopted a quasi-Monte Carlo (QMC) sampling approach to effectively explore the high dimensional parameter space. The output response variables (e.g., FNET) were simulated using CAM5 for each parameter set, and then evaluated using generalized linear model analysis. In response to the perturbations of these 16 parameters, the CAM5-simulated global annual mean FNET ranges from -9.8 to 3.5 W m-2 compared to the CAM5-simulated FNET of 1.9 W m-2 with the default parameter values. Variance-based sensitivity analysis was conducted to show the relative contributions of individual parameter perturbation to the global FNET variance. The results indicate that the changes in the global mean FNET are dominated by those of cloud forcing (CF) within the parameter ranges being investigated. The size threshold parameter related to auto-conversion of cloud ice to snow is confirmed as one of the most influential parameters for FNET in the CAM5 simulation. The strong heterogeneous geographic distribution of FNET variation shows parameters have a clear localized effect over regions where they are acting. However, some parameters also have non-local impacts on FNET variance. Although external factors, such as perturbations of anthropogenic and natural emissions, largely affect FNET variations at the regional scale, their impact is weaker than that of model internal parameters in terms of simulating global mean FNET in this study. The interactions among the 16 selected parameters contribute a relatively small portion of the total FNET variations over most regions of the globe. This study helps us better understand the CAM5 model behavior associated with parameter uncertainties, which will aid the next step of reducing model

  2. Potential Aerosol Indirect Effects on Atmospheric Circulation...

    Office of Scientific and Technical Information (OSTI)

    the complex processes involved are poorly understood and represented in climate models. Here we report that aerosol indirect effect on deep convective cloud systems can lead ...

  3. Aerosol indirect effects - general circulation model intercomparison...

    Office of Scientific and Technical Information (OSTI)

    We compute statistical relationships between aerosol optical depth (a) and various cloud ... Nevertheless, the strengths of the statistical relationships are good predictors for the ...

  4. Aerosol Observing System (AOS) Handbook

    SciTech Connect (OSTI)

    Jefferson, A

    2011-01-17

    The Aerosol Observing System (AOS) is a suite of in situ surface measurements of aerosol optical and cloud-forming properties. The instruments measure aerosol properties that influence the earths radiative balance. The primary optical measurements are those of the aerosol scattering and absorption coefficients as a function of particle size and radiation wavelength and cloud condensation nuclei (CCN) measurements as a function of percent supersaturation. Additional measurements include those of the particle number concentration and scattering hygroscopic growth. Aerosol optical measurements are useful for calculating parameters used in radiative forcing calculations such as the aerosol single-scattering albedo, asymmetry parameter, mass scattering efficiency, and hygroscopic growth. CCN measurements are important in cloud microphysical models to predict droplet formation.

  5. Cloud and aerosol characterization for the ARM central facility: Multiple remote sensor techniques development. Technical progress report

    SciTech Connect (OSTI)

    Sassen, K.

    1992-04-30

    This research project designed to investigate how atmospheric remote sensing technology can best be applied to the characterization of the cloudy atmosphere. Our research program addresses basic atmospheric remote sensing questions, but at the same time is clearly directed toward providing information crucial to the ARM (Atmospheric Remote Sensing) program and for application to the Clouds and Radiation Testbed (CART). The instrumentation that is being brought into play includes a variety of art-of-the-art sensors. Available at NOAA WPL are polarization Doppler K{sub a}-band (0.86 mm) and X-band (3.2 cm) radars, a C0{sub 2}(10.6 {mu}m) Doppler lidar with sequential ` polarization measurement capabilities, a three-channel (20.6, 31.65 and 90 GHz) microwave radiometer, and variety of visible and infrared radiometers. Instrumentation at the University of Utah Facility for Atmospheric Remote Sensing (FARS) includes a polarization ruby (0.643 {mu}m) lidar, a narrow-beam (0.14{degree}) mid-infrared (9.5--11.5 {mu}m) radiometer coaligned with the lidar, several other radiometers in the visible and infrared spectral regions, and an advanced two-color (1.06 and 0.532 {mu}m), four-channel Polarization Diversity Lidar (PDL) and all-sky video imaging system that have only recently been developed under the ARM IDP.

  6. ARM - Field Campaign - Cloud Radar IOP

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    of aerosol properties during clear-sky conditions. The ETL Radar Meteorology and Oceanography Division will field their NOAAK scanning cloud radar near the new ARM millimeter...

  7. ARM Cloud Properties Working Group: Meeting Logistics

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    to 1630: J. Comstock - Clouds with Low Optical Water Depth (CLOWD) 1630 to 1645: B. Albrecht - Clouds, Aerosol, and Precipitation in the Marine Boundary Layer (CLAP-MBL) 1645 to ...

  8. Atmospheric Rivers Coming to a Cloud Near You (Other) | SciTech...

    Office of Scientific and Technical Information (OSTI)

    Title: Atmospheric Rivers Coming to a Cloud Near You Learn about the ARM Cloud Aerosol ... Country of Publication: United States Language: English Subject: 54 ENVIRONMENTAL SCIENCES ...

  9. AERONET: The Aerosol Robotic Network

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    AERONET collaboration provides globally distributed observations of spectral aerosol optical Depth (AOD), inversion products, and precipitable water in diverse aerosol regimes. Aerosol optical depth data are computed for three data quality levels: Level 1.0 (unscreened), Level 1.5 (cloud-screened), and Level 2.0 (cloud screened and quality-assured). Inversions, precipitable water, and other AOD-dependent products are derived from these levels and may implement additional quality checks.[Copied from http://aeronet.gsfc.nasa.gov/new_web/system_descriptions.html

  10. ARM Cloud Aerosol Precipitation Experiment

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Experiment a NOAA ship in the Pacific Ocean and on a DOE- sponsored plane over land and sea. These researchers will study: (1) water sources, evolution and structure of...

  11. ARM - Field Campaign - Two-Column Aerosol Project (TCAP)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Browse Data Related Campaigns Two-Column Aerosol Project (TCAP): Field Evaluation of Real-time Cloud OD Sensor TWST 2013.04.15, Scott, AMF Two-Column Aerosol Project (TCAP): Winter ...

  12. Marine ARM GPCI Investigation of Clouds (MAGIC) Science Objectives and Significance

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ARM GPCI Investigation of Clouds (MAGIC) Science Objectives and Significance Every cloud in the sky begins as a tiny droplet, which forms around an even smaller particle called an aerosol particle. Some clouds produce precipitation, and some don't. The relationship between clouds, precipitation, and aerosols is very complex and very important. Scientists use data about clouds, precipitation, and aerosols to develop computer codes, or models, that simulate what's happening in the atmosphere and

  13. Research Highlight

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    MBL Aerosol Properties and Their Impact on CCN at the Azores-AMF Site Download a printable PDF Submitter: Dong, X., University of Arizona Area of Research: Aerosol Properties Working Group(s): Cloud-Aerosol-Precipitation Interactions Journal Reference: Logan T, B Xi, and X Dong. 2014. "Aerosol properties and their influences on marine boundary layer cloud condensation nuclei at the ARM mobile facility over the Azores." Journal of Geophysical Research - Atmospheres, 119(8),

  14. Final Report for Research Conducted at The Scripps Institution of Oceanography, University of California San Diego from 2/2002 to 8/2003 for ''Aerosol and Cloud-Field Radiative Effects in the Tropical Western Pacific: Analyses and General Circulation Model Parameterizations''

    SciTech Connect (OSTI)

    Vogelmann, A. M.

    2004-01-27

    OAK-B135 Final report from the University of California San Diego for an ongoing research project that was moved to Brookhaven National Laboratory where proposed work will be completed. The research uses measurements made by the Atmospheric Radiation Measurement (ARM) Program to quantify the effects of aerosols and clouds on the Earth's energy balance in the climatically important Tropical Western Pacific.

  15. ARM - Field Campaign - Two-Column Aerosol Project (TCAP): Winter...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    on atmospheric particulate matter. The effect of aerosol properties such as size, morphology and composition on cloud droplet formation has been studied theoretically as well as...

  16. Direct Aerosol Forcing: Calculation from Observables and Sensitivities...

    Office of Scientific and Technical Information (OSTI)

    ... Language: English Subject: 54 ENVIRONMENTAL SCIENCES; AEROSOLS; ... SOLAR RADIATION; MATHEMATICAL MODELS Word Cloud More Like This Full Text Journal Articles DOI: 10.1029...

  17. Predicting Aerosol Direct Radiative Forcing over Mexico using...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Use Weather Research and Forecasting (WRF) model as the foundation of computational framework * Fully-coupled aerosol-radiation-cloud-chemistry interactions * Handles multiple ...

  18. Study of Mechanisms of Aerosol Indirect Effects on Glaciated...

    Office of Scientific and Technical Information (OSTI)

    ... clouds, was seen to be of higher importance in regulating aerosol indirect effects ... DOE Contract Number: SC0007396 Resource Type: Technical Report Research Org: Leeds ...

  19. Holistic Interactions of Shallow Clouds,

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Holistic Interactions of Shallow Clouds, Aerosols, and Land-Ecosystems Research Instrumentation HI-SCALE will utilize the ARM Aerial Facility's Gulfstream-159 (G-1), as well as ground instrumentation located at the SGP megasite. 7e G-1 will complete transects over the site at multiple altitudes within the boundary layer, within clouds, and above clouds. 7e payload on the G-1 includes: * high frequency meteorological and radiation (both up and downwelling) measurements that also permit computing

  20. The Radiative Properties of Small Clouds: Multi-Scale Observations...

    Office of Scientific and Technical Information (OSTI)

    characterize shallow clouds and the role of aerosol in modifying their radiative effects. ... Sponsoring Org: USDOE Country of Publication: United States Language: English Subject: 54 ...

  1. Atmospheric Rivers Coming to a Cloud Near You

    ScienceCinema (OSTI)

    Leung, Ruby

    2014-06-12

    Learn about the ARM Cloud Aerosol Precipitation Experiment (ACAPEX) field campaign in this short video. Ruby Leung, PNNL's lead scientist on this campaign's observational strategy to monitor precipitation.

  2. Atmospheric Rivers Coming to a Cloud Near You

    SciTech Connect (OSTI)

    Leung, Ruby

    2014-03-29

    Learn about the ARM Cloud Aerosol Precipitation Experiment (ACAPEX) field campaign in this short video. Ruby Leung, PNNL's lead scientist on this campaign's observational strategy to monitor precipitation.

  3. Polluting of Winter Convective Clouds upon Transition from Ocean...

    Office of Scientific and Technical Information (OSTI)

    These findings provide the motivation for deeper investigations into the nature of the aerosols seeding clouds. less Authors: Rosenfeld, Daniel ; Chemke, Rei ; Prather, Kimberly ...

  4. ARM - Field Campaign - Holistic Interactions of Shallow Clouds...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Holistic Interactions of Shallow Clouds, Aerosols, and Land-Ecosystems (HI-SCALE); National Geospatial-Intelligence Agency Calibration Target Placements 2016.04.24, Kalukin, SGP ...

  5. Characterization of 3D Cirrus Cloud and Radiation Fields Using...

    Office of Scientific and Technical Information (OSTI)

    aerosol number concentration, ice cloud water path, and ice particle number ... effective ice crystal size (De) and ice water content (IWC) by dividing the atmosphere ...

  6. ARM - Routine AAF Clouds with Low Optical Water Depths (CLOWD...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    News Discovery Channel Earth Live Blog News & Press RACORO Backgrounder (PDF, 528K) ... will obtain representative statistics of cloud microphysical, aerosol, and ...

  7. CARES: Carbonaceous Aerosol and Radiative Effects Study Science Plan

    SciTech Connect (OSTI)

    Zaveri, RA; Shaw, WJ; Cziczo, DJ

    2010-05-27

    Carbonaceous aerosol components, which include black carbon (BC), urban primary organic aerosols (POA), biomass burning aerosols, and secondary organic aerosols (SOA) from both urban and biogenic precursors, have been previously shown to play a major role in the direct and indirect radiative forcing of climate. The primary objective of the CARES 2010 intensive field study is to investigate the evolution of carbonaceous aerosols of different types and their effects on optical and cloud formation properties.

  8. Determining Best Estimates and Uncertainties in Cloud Microphysical

    Office of Scientific and Technical Information (OSTI)

    Parameters from ARM Field Data: Implications for Models, Retrieval Schemes and Aerosol-Cloud-Radiation Interactions (Technical Report) | SciTech Connect Determining Best Estimates and Uncertainties in Cloud Microphysical Parameters from ARM Field Data: Implications for Models, Retrieval Schemes and Aerosol-Cloud-Radiation Interactions Citation Details In-Document Search Title: Determining Best Estimates and Uncertainties in Cloud Microphysical Parameters from ARM Field Data: Implications for

  9. Final Report for ?¢????Cloud-Aerosol Physics in Super-Parameterized Atmospheric Regional Climate Simulations (CAP-SPARCS)?¢??? (DE-SC0002003) for 8/15/2009 through 8/14/2012

    SciTech Connect (OSTI)

    Lynn M. Russell; Richard C.J. Somerville

    2012-11-05

    Improving the representation of local and non-local aerosol interactions in state-of-the-science regional climate models is a priority for the coming decade (Zhang, 2008). With this aim in mind, we have combined two new technologies that have a useful synergy: (1) an aerosol-enabled regional climate model (Advanced Weather Research and Forecasting Model with Chemistry WRF-Chem), whose primary weakness is a lack of high quality boundary conditions and (2) an aerosol-enabled multiscale modeling framework (PNNL Multiscale Aerosol Climate Model (MACM)), which is global but captures aerosol-convection-cloud feedbacks, and thus an ideal source of boundary conditions. Combining these two approaches has resulted in an aerosol-enabled modeling framework that not only resolves high resolution details in a particular region, but crucially does so within a global context that is similarly faithful to multi-scale aerosol-climate interactions. We have applied and improved the representation of aerosol interactions by evaluating model performance over multiple domains, with (1) an extensive evaluation of mid-continent precipitation representation by multiscale modeling, (2) two focused comparisons to transport of aerosol plumes to the eastern United States for comparison with observations made as part of the International Consortium for Atmospheric Research on Transport and Transformation (ICARTT), with the first being idealized and the second being linked to an extensive wildfire plume, and (3) the extension of these ideas to the development of a new approach to evaluating aerosol indirect effects with limited-duration model runs by ?¢????nudging?¢??? to observations. This research supported the work of one postdoc (Zhan Zhao) for two years and contributed to the training and research of two graduate students. Four peer-reviewed publications have resulted from this work, and ground work for a follow-on project was completed.

  10. Raman lidar measurements of water vapor and aerosols during the atmospheric radiation measurement (ARM) remote clouds sensing (RCS) intensive observation period (IOP)

    SciTech Connect (OSTI)

    Melfi, S.H.; Starr, D.O`C.; Whiteman, D.

    1996-04-01

    The first Atmospheric Radiation Measurement (ARM) remote Cloud Study (RCS) Intensive Operations Period (IOP) was held during April 1994 at the Southern Great Plains (SGP) site. This experiment was conducted to evaluate and calibrate state-of-the-art, ground based remote sensing instruments and to use the data acquired by these instruments to validate retrieval algorithms developed under the ARM program.

  11. AERONET: The Aerosol Robotic Network

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    The AERONET (AErosol RObotic NETwork) program is a federation of ground-based remote sensing aerosol networks established by NASA and LOA-PHOTONS (CNRS) and is greatly expanded by collaborators from national agencies, institutes, universities, individual scientists, and partners. The program provides a long-term, continuous and readily accessible public domain database of aerosol optical, mircrophysical and radiative properties for aerosol research and characterization, validation of satellite retrievals, and synergism with other databases. The network imposes standardization of instruments, calibration, processing and distribution. AERONET collaboration provides globally distributed observations of spectral aerosol optical Depth (AOD), inversion products, and precipitable water in diverse aerosol regimes. Aerosol optical depth data are computed for three data quality levels: Level 1.0 (unscreened), Level 1.5 (cloud-screened), and Level 2.0 (cloud screened and quality-assured). Inversions, precipitable water, and other AOD-dependent products are derived from these levels and may implement additional quality checks.[Copied from http://aeronet.gsfc.nasa.gov/new_web/system_descriptions.html

  12. Science Overview Document Indirect and Semi-Direct Aerosol Campaign (ISDAC) April 2008

    SciTech Connect (OSTI)

    SJ Ghan; B Schmid; JM Hubbe; CJ Flynn; A Laskin; AA Zelenyuk; DJ Czizco; CN Long; G McFarquhar; J Verlinde; J Harrington; JW Strapp; P Liu; A Korolev; A McDonald; M Wolde; A Fridlind; T Garrett; G Mace; G Kok; S Brooks; D Collins; D Lubin; P Lawson; M Dubey; C Mazzoleni; M Shupe; S Xie; DD Turner; Q Min; EJ Mlawer; D Mitchell

    2007-11-01

    The ARM Climate Research Facility’s (ACRF) Aerial Vehicle Program (AVP) will deploy an intensive cloud and aerosol observing system to the ARM North Slope of Alaska (NSA) locale for a five week Indirect and Semi-Direct Aerosol Campaign (ISDAC) during period 29 March through 30 April 2008. The deployment period is within the International Polar Year, thus contributing to and benefiting from the many ancillary observing systems collecting data synergistically. We will deploy the Canadian National Research Council Convair 580 aircraft to measure temperature, humidity, total particle number, aerosol size distribution, single particle composition, concentrations of cloud condensation nuclei and ice nuclei, optical scattering and absorption, updraft velocity, cloud liquid water and ice contents, cloud droplet and crystal size distributions, cloud particle shape, and cloud extinction. In addition to these aircraft measurements, ISDAC will deploy two instruments at the ARM site in Barrow: a spectroradiometer to retrieve cloud optical depth and effective radius, and a tandem differential mobility analyzer to measure the aerosol size distribution and hygroscopicity. By using many of the same instruments used during Mixed-Phase Arctic Cloud Experiment (M-PACE), conducted in October 2004, we will be able to contrast the arctic aerosol and cloud properties during the fall and spring transitions. The aerosol measurements can be used in cloud models driven by objectively analyzed boundary conditions to test whether the cloud models can simulate the aerosol influence on the clouds. The influence of aerosol and boundary conditions on the simulated clouds can be separated by running the cloud models with all four combinations of M-PACE and ISDAC aerosol and boundary conditions: M-PACE aerosol and boundary conditions, M-PACE aerosol and ISDAC boundary conditions, ISDAC aerosol and M-PACE boundary conditions, and ISDAC aerosol and boundary conditions. ISDAC and M-PACE boundary

  13. Long-term impacts of aerosols on the vertical development of...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Long-term impacts of aerosols on the vertical development of clouds and precipitation Citation Details In-Document Search Title: Long-term impacts of aerosols on ...

  14. ARM - Data Announcements Article

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2, 2009 [Data Announcements] Data Plots Available for the ARM Mobile Facility Deployment in the Azores Bookmark and Share Data plots, like this one, are now available from the ARM Mobile Facility deployment on Graciosa Island in the Azores. The 20-month deployment of the ARM Mobile Facility on Graciosa Island in the Azores is well underway in support of the Clouds, Aerosol, and Precipitation in the Marine Boundary Layer field campaign. Data are being collected to study the seasonal life cycle of

  15. Storm Peak Lab Cloud Property Validation

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Peak Lab Cloud Property Validation Experiment (STORMVEX) Operated by the Atmospheric Radiation Measurement (ARM) Climate Research Facility for the U.S. Department of Energy, the second ARM Mobile Facility (AMF2) begins its inaugural deployment November 2010 in Steamboat Springs, Colorado, for the Storm Peak Lab Cloud Property Validation Experiment, or STORMVEX. For six months, the comprehensive suite of AMF2 instruments will obtain measurements of cloud and aerosol properties at various sites

  16. Systematic Flights Obtain Long-Term Data Set of Cloud Properties

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    instrumentation to complete routine flights over the SGP site and obtain representative statistics of cloud microphysical, aerosol, and radiative properties of the atmosphere. ...

  17. Layered Atlantic Smoke Interactions with Clouds (LASIC) Science Plan

    SciTech Connect (OSTI)

    Zuidema, P; Chiu, C; Fairall, CW; Ghan, SJ; Kollias, P; McFarguhar, GM; Mechem, DB; Romps, DM; Wong, H; Yuter, SE; Alvarado, MJ; DeSzoeke, SP; Feingold, G; Haywood, JM; Lewis, ER; McComiskey, A; Redemann, J; Turner, DD; Wood, R; Zhu, P

    2015-12-01

    Southern Africa is the world’s largest emitter of biomass-burning (BB) aerosols. Their westward transport over the remote southeast Atlantic Ocean colocates some of the largest atmospheric loadings of absorbing aerosol with the least examined of the Earth’s major subtropical stratocumulus decks. Global aerosol model results highlight that the largest positive top-of-atmosphere forcing in the world occurs in the southeast Atlantic, but this region exhibits large differences in magnitude and sign between reputable models, in part because of high variability in the underlying model cloud distributions. Many uncertainties contribute to the highly variable model radiation fields: the aging of shortwave-absorbing aerosol during transport, how much of the aerosol mixes into the cloudy boundary layer, and how the low clouds adjust to smoke-radiation and smoke-cloud interactions. In addition, the ability of the BB aerosol to absorb shortwave radiation is known to vary seasonally as the fuel type on land changes.

  18. Research Highlight

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    MBL Cloud Properties Derived from the Azores-AMF Observations Submitter: Dong, X., University of Arizona Area of Research: Cloud Processes Working Group(s): Cloud-Aerosol-Precipitation Interactions Journal Reference: Dong X, B Xi, A Kennedy, P Minnis, and R Wood. 2014. "A 19-month record of marine aerosol-cloud-radiation properties derived from DOE ARM AMF deployment at the Azores: Part I: Cloud fraction and single-layered MBL cloud properties." Journal of Climate, 27(10),

  19. Advancing Models and Evaluation of Cumulus, Climate and Aerosol Interactions

    SciTech Connect (OSTI)

    Gettelman, Andrew

    2015-10-27

    This project was successfully able to meet its’ goals, but faced some serious challenges due to personnel issues. Nonetheless, it was largely successful. The Project Objectives were as follows: 1. Develop a unified representation of stratifom and cumulus cloud microphysics for NCAR/DOE global community models. 2. Examine the effects of aerosols on clouds and their impact on precipitation in stratiform and cumulus clouds. We will also explore the effects of clouds and precipitation on aerosols. 3. Test these new formulations using advanced evaluation techniques and observations and release

  20. Prediction of cloud droplet number in a general circulation model

    SciTech Connect (OSTI)

    Ghan, S.J.; Leung, L.R.

    1996-04-01

    We have applied the Colorado State University Regional Atmospheric Modeling System (RAMS) bulk cloud microphysics parameterization to the treatment of stratiform clouds in the National Center for Atmospheric Research Community Climate Model (CCM2). The RAMS predicts mass concentrations of cloud water, cloud ice, rain and snow, and number concnetration of ice. We have introduced the droplet number conservation equation to predict droplet number and it`s dependence on aerosols.

  1. ARM - Field Campaign - Marine ARM GPCI Investigation of Clouds (MAGIC)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    govCampaignsMarine ARM GPCI Investigation of Clouds (MAGIC) Campaign Links MAGIC Website ARM Data Discovery Browse Data Related Campaigns Marine ARM GPCI Investigations of Clouds (MAGIC): Measuring the Composition of Aerosol Particles 2013.07.01, Lewis, AMF Marine ARM GPCI Investigation of Clouds (MAGIC): Shortwave Hyperspectral Observations 2013.07.01, McBride, AMF Marine ARM GPCI Investigation of Clouds (MAGIC): Marine Ice Nuclei Collections 2013.06.01, DeMott, AMF Marine ARM GPCI

  2. Assessing the Effects of Anthropogenic Aerosols on Pacific Storm Track Using a Multiscale Global Climate Model

    SciTech Connect (OSTI)

    Wang, Yuan; Wang, Minghuai; Zhang, Renyi; Ghan, Steven J.; Lin, Yun; Hu, Jiaxi; Pan, Bowen; Levy, Misti; Jiang, Jonathan; Molina, Mario J.

    2014-05-13

    Atmospheric aerosols impact weather and global general circulation by modifying cloud and precipitation processes, but the magnitude of cloud adjustment by aerosols remains poorly quantified and represents the largest uncertainty in estimated forcing of climate change. Here we assess the impacts of anthropogenic aerosols on the Pacific storm track using a multi-scale global aerosol-climate model (GCM). Simulations of two aerosol scenarios corresponding to the present day and pre-industrial conditions reveal long-range transport of anthropogenic aerosols across the north Pacific and large resulting changes in the aerosol optical depth, cloud droplet number concentration, and cloud and ice water paths. Shortwave and longwave cloud radiative forcing at the top of atmosphere are changed by - 2.5 and + 1.3 W m-2, respectively, by emission changes from pre-industrial to present day, and an increased cloud-top height indicates invigorated mid-latitude cyclones. The overall increased precipitation and poleward heat transport reflect intensification of the Pacific storm track by anthropogenic aerosols. Hence, this work provides for the first time a global perspective of the impacts of Asian pollution outflows from GCMs. Furthermore, our results suggest that the multi-scale modeling framework is essential in producing the aerosol invigoration effect of deep convective clouds on the global scale.

  3. Atmospheric Science Program Cumulus Humilis Aerosol Processing Study (CHAPS)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Program Cumulus Humilis Aerosol Processing Study (CHAPS) General Description 'Cumulus humilis' is the scientific term used to describe the small fair weather clouds that dot the summer skies over Oklahoma. During the month of June, scientists sponsored by the U.S. Department of Energy's Atmospheric Science Program will use aircraft and ground based instruments to obtain information about the physical and chemical properties of these clouds and the small airborne particles - called aerosols -

  4. Total aerosol effect: forcing or radiative flux perturbation?

    SciTech Connect (OSTI)

    Lohmann, Ulrike; Storelvmo, Trude; Jones, Andy; Rotstayn, Leon; Menon, Surabi; Quaas, Johannes; Ekman, Annica; Koch, Dorothy; Ruedy, Reto

    2009-09-25

    Uncertainties in aerosol forcings, especially those associated with clouds, contribute to a large extent to uncertainties in the total anthropogenic forcing. The interaction of aerosols with clouds and radiation introduces feedbacks which can affect the rate of rain formation. Traditionally these feedbacks were not included in estimates of total aerosol forcing. Here we argue that they should be included because these feedbacks act quickly compared with the time scale of global warming. We show that for different forcing agents (aerosols and greenhouse gases) the radiative forcings as traditionally defined agree rather well with estimates from a method, here referred to as radiative flux perturbations (RFP), that takes these fast feedbacks and interactions into account. Thus we propose replacing the direct and indirect aerosol forcing in the IPCC forcing chart with RFP estimates. This implies that it is better to evaluate the total anthropogenic aerosol effect as a whole.

  5. Precipitating clouds

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    A suggestion for a new focus on cloud microphysical process study in the ARM program 1. Retrieving precipitating mixed- phase cloud properties Zhien Wang University of Wyoming zwang@uwyo.edu Retrieving Precipitating Mixed-phase Cloud Properties Global distribution of supercooled water topped stratiform clouds (top > 1 km and length> 14km) Most of them are mixed-phase with precipitation or virga An multiple sensor based approach to provide water phase as well as ice phase properties

  6. Enhanced toxic cloud knockdown spray system for decontamination applications

    DOE Patents [OSTI]

    Betty, Rita G.; Tucker, Mark D.; Brockmann, John E.; Lucero, Daniel A.; Levin, Bruce L.; Leonard, Jonathan

    2011-09-06

    Methods and systems for knockdown and neutralization of toxic clouds of aerosolized chemical or biological warfare (CBW) agents and toxic industrial chemicals using a non-toxic, non-corrosive aqueous decontamination formulation.

  7. Comparison of the Vertical Velocity Used to Calculate the Cloud Droplet Number Concentration in a Cloud Resolving and a Global Climate Model

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Comparison of the Vertical Velocity used to Calculate the Cloud Droplet Number Concentration in a Cloud-Resolving and a Global Climate Model H. Guo, J. E. Penner, M. Herzog, and X. Liu Department of Atmospheric, Oceanic and Space Sciences University of Michigan Ann Arbor, Michigan Introduction Anthropogenic aerosols are effective cloud condensation nuclei (CCN). The availability of CCN affects the initial cloud droplet number concentration (CDNC) and droplet size; therefore, cloud optical

  8. Layered Atlantic Smoke Interactions with Clouds (LASIC) Science Plan

    Office of Scientific and Technical Information (OSTI)

    (Program Document) | SciTech Connect Layered Atlantic Smoke Interactions with Clouds (LASIC) Science Plan Citation Details In-Document Search Title: Layered Atlantic Smoke Interactions with Clouds (LASIC) Science Plan Southern Africa is the world's largest emitter of biomass-burning (BB) aerosols. Their westward transport over the remote southeast Atlantic Ocean colocates some of the largest atmospheric loadings of absorbing aerosol with the least examined of the Earth's major subtropical

  9. Biogenic Aerosols Effects on Climate and Clouds Cloud OD Sensor...

    Office of Scientific and Technical Information (OSTI)

    ... Because of our direct connection to the Internet, virus software protection was installed and frequent virus scans were scheduled at night. 4.0 TWST Data Catalog TWST was deployed ...

  10. Slide 1

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    CAP-MBL) Importance of Low-Clouds for Climate Imperative that we understand the processes controlling the formation, maintenance and dissipation of low clouds in order to improve their representation in climate models. Aerosol-Cloud-Drizzle Interactions Precipitation and its effects in the MBL over oceans No long-term records exist that can be used to link cloud, precipitation, and aerosol microphysical variability in the remote-capped MBL. Scientific Goals of AMF Deployment to Azores Cloud

  11. ARM - Field Campaign - MArine Stratus Radiation Aerosol and Drizzle

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    (MASRAD) IOP govCampaignsMArine Stratus Radiation Aerosol and Drizzle (MASRAD) IOP Campaign Links Science Plan AMF Point Reyes Website AMF Point Reyes Data Plots ARM Data Discovery Browse Data Related Campaigns MASRAD: Pt. Reyes Stratus Cloud and Drizzle Study 2005.07.07, Coulter, AMF MASRAD: Cloud Condensate Nuclei Chemistry Measurements 2005.07.01, Berkowitz, AMF MASRAD - Aerosol Optical Properties 2005.06.29, Strawa, AMF MASRAD:Sub-Micron Aerosol Measurements 2005.06.20, Wang, AMF MASRAD:

  12. Microsoft Word - Aerosol Working Group_Norfolk 2008.doc

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ARM Aerosol Working Group, Agenda, Monday, March 10, 2008 15:00 0:13 Flynn 4STAR - a next-generation spectrometer for sky-scanning solar tracking radiometry 15:13 0:13 Yu FastTRAC 15:26 0:13 Obland Initial Airborne High Spectral Resolution Lidar (HSRL) Results from the Cumulus Humilis Aerosol Processing Study (CHAPS) and Cloud and Land Surface Interaction Campaign (CLASIC) 15:39 0:13 Kim Efficacy of Aerosol - Cloud Interactions Under Varying Meteorological Conditions: Southern Great Plains Vs.

  13. Assessing regional scale predictions of aerosols, marine stratocumulus, and their interactions during VOCALS-REx using WRF-Chem

    SciTech Connect (OSTI)

    Yang Q.; Lee Y.; Gustafson Jr., W. I.; Fast, J. D.; Wang, H.; Easter, R. C.; Morrison, H.; Chapman, E. G.; Spak, S. N.; Mena-Carrasco, M. A.

    2011-12-02

    This study assesses the ability of the recent chemistry version (v3.3) of the Weather Research and Forecasting (WRF-Chem) model to simulate boundary layer structure, aerosols, stratocumulus clouds, and energy fluxes over the Southeast Pacific Ocean. Measurements from the VAMOS Ocean-Cloud-Atmosphere-Land Study Regional Experiment (VOCALS-REx) and satellite retrievals (i.e., products from the MODerate resolution Imaging Spectroradiometer (MODIS), Clouds and Earth's Radiant Energy System (CERES), and GOES-10) are used for this assessment. The Morrison double-moment microphysics scheme is newly coupled with interactive aerosols in the model. The 31-day (15 October-16 November 2008) WRF-Chem simulation with aerosol-cloud interactions (AERO hereafter) is also compared to a simulation (MET hereafter) with fixed cloud droplet number concentrations in the microphysics scheme and simplified cloud and aerosol treatments in the radiation scheme. The well-simulated aerosol quantities (aerosol number, mass composition and optical properties), and the inclusion of full aerosol-cloud couplings lead to significant improvements in many features of the simulated stratocumulus clouds: cloud optical properties and microphysical properties such as cloud top effective radius, cloud water path, and cloud optical thickness. In addition to accounting for the aerosol direct and semi-direct effects, these improvements feed back to the simulation of boundary-layer characteristics and energy budgets. Particularly, inclusion of interactive aerosols in AERO strengthens the temperature and humidity gradients within the capping inversion layer and lowers the marine boundary layer (MBL) depth by 130 m from that of the MET simulation. These differences are associated with weaker entrainment and stronger mean subsidence at the top of the MBL in AERO. Mean top-of-atmosphere outgoing shortwave fluxes, surface latent heat, and surface downwelling longwave fluxes are in better agreement with observations

  14. ARM - Measurement - Cloud size

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    measurements as cloud thickness, cloud area, and cloud aspect ratio. Categories Cloud Properties Instruments The above measurement is considered scientifically relevant for the...

  15. MAGIC Cloud Properties from Zenith Radiance Data Final Campaign Summary

    SciTech Connect (OSTI)

    Chiu, J. -Y.C.; Gregory, L.; Wagener, R.

    2016-01-01

    Cloud droplet size and optical depth are the most fundamental properties for understanding cloud formation, dissipation and interactions with aerosol and drizzle. They are also a crucial determinant of Earth’s radiative and water-energy balances. However, these properties are poorly predicted in climate models. As a result, the response of clouds to climate change is one of the major sources of uncertainty in climate prediction.

  16. Vertical Velocities in Continental Boundary Layer Stratocumulus Clouds

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Velocities in Continental Boundary Layer Stratocumulus Clouds Virendra Ghate Bruce Albrecht and Pavlos Kollias Why BL Stratocumulus?? * Extensive Coverage - Cover ~24% of earth's surface - Persist of long time-scales * Impact on radiation budget - High SW albedo compared to land or ocean Klein and Hartmann 1993 But Why Continental Clouds? * They do exist - Monthly cloud fraction can vary from 10% to 23% * Impact on pollution & Diurnal Cycle - Affect pollutant venting out of BL & Aerosol

  17. Macquarie Island Cloud and Radiation Experiment Science Objective

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Macquarie Island Cloud and Radiation Experiment Science Objective The overarching objective of this field campaign is to make observations of the surface broadband radiative fluxes in combination with other measurements useful in characterizing cloud and aerosol properties. In addition to having large uncertainties, satellite data sets for the Southern Ocean are incomplete because they are not continuous, rarely sample the diurnal cycle, and view primarily the tops of cloud systems. This is

  18. North Atlantic Science Objective

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and Cloud Experiments in Eastern North Atlantic Science Objective 7e overarching scientiIc objective of ACE-ENA is to understand key processes that drive the properties and interactions between aerosol and cloud under a variety of representative meteorological and cloud conditions. ACE- ENA will collect comprehensive in situ data of boundary layer and lower free troposphere structure and associated vertical distributions and horizontal variations of low clouds and aerosol in the Azores.

  19. ARM - Measurement - Aerosol concentration

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    CSPHOT : Cimel Sunphotometer CPC : Condensation Particle Counter HTDMA : Humidified Tandem Differential Mobility Analyzer IAP : In-situ Aerosol Profiles (Cessna Aerosol Flights)...

  20. Ganges Valley Aerosol Experiment (GVAX) Final Campaign Report

    SciTech Connect (OSTI)

    Kotamarthi, VR

    2013-12-01

    In general, the Indian Summer Monsoon (ISM) as well as the and the tropical monsoon climate is influenced by a wide range of factors. Under various climate change scenarios, temperatures over land and into the mid troposphere are expected to increase, intensifying the summer pressure gradient differential between land and ocean and thus strengthening the ISM. However, increasing aerosol concentration, air pollution, and deforestation result in changes to surface albedo and insolation, potentially leading to low monsoon rainfall. Clear evidence points to increasing aerosol concentrations over the Indian subcontinent with time, and several hypotheses regarding the effect on monsoons have been offered. The Ganges Valley Aerosol Experiment (GVAX) field study aimed to provide critical data to address these hypotheses and contribute to developing better parameterizations for tropical clouds, convection, and aerosol-cloud interactions. The primary science questions for the mission were as follows:

  1. ARM - Measurement - Cloud type

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Measurement : Cloud type Cloud type such as cirrus, stratus, cumulus etc Categories Cloud Properties Instruments The above measurement is considered scientifically relevant for the...

  2. Observed Aerosol Radiative Forcings: Comparison for Natural and Anthropogenic Sources

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Aerosol Radiative Forcings: Comparison for Natural and Anthropogenic Sources A. M. Vogelmann Center for Atmospheric Sciences and Center for Clouds, Chemistry and Climate Scripps Institution of Oceanography University of California San Diego, California Introduction The modeling of radiative forcing, and aerosol radiative forcing in particular, is one of the largest uncertainties in predicting climate change (Hansen et al. 1998). Addressing this uncertainty first requires an accurate

  3. Cloud-Scale Vertical Velocity and Turbulent Dissipation Rate Retrievals

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Shupe, Matthew

    Time-height fields of retrieved in-cloud vertical wind velocity and turbulent dissipation rate, both retrieved primarily from vertically-pointing, Ka-band cloud radar measurements. Files are available for manually-selected, stratiform, mixed-phase cloud cases observed at the North Slope of Alaska (NSA) site during periods covering the Mixed-Phase Arctic Cloud Experiment (MPACE, late September through early November 2004) and the Indirect and Semi-Direct Aerosol Campaign (ISDAC, April-early May 2008). These time periods will be expanded in a future submission.

  4. Cloud-Scale Vertical Velocity and Turbulent Dissipation Rate Retrievals

    SciTech Connect (OSTI)

    Shupe, Matthew

    2013-05-22

    Time-height fields of retrieved in-cloud vertical wind velocity and turbulent dissipation rate, both retrieved primarily from vertically-pointing, Ka-band cloud radar measurements. Files are available for manually-selected, stratiform, mixed-phase cloud cases observed at the North Slope of Alaska (NSA) site during periods covering the Mixed-Phase Arctic Cloud Experiment (MPACE, late September through early November 2004) and the Indirect and Semi-Direct Aerosol Campaign (ISDAC, April-early May 2008). These time periods will be expanded in a future submission.

  5. Climate implications of carbonaceous aerosols: An aerosol microphysical study using the GISS/MATRIX climate model

    SciTech Connect (OSTI)

    Bauer, Susanne E.; Menon, Surabi; Koch, Dorothy; Bond, Tami; Tsigaridis, Kostas

    2010-04-09

    Recently, attention has been drawn towards black carbon aerosols as a likely short-term climate warming mitigation candidate. However the global and regional impacts of the direct, cloud-indirect and semi-direct forcing effects are highly uncertain, due to the complex nature of aerosol evolution and its climate interactions. Black carbon is directly released as particle into the atmosphere, but then interacts with other gases and particles through condensation and coagulation processes leading to further aerosol growth, aging and internal mixing. A detailed aerosol microphysical scheme, MATRIX, embedded within the global GISS modelE includes the above processes that determine the lifecycle and climate impact of aerosols. This study presents a quantitative assessment of the impact of microphysical processes involving black carbon, such as emission size distributions and optical properties on aerosol cloud activation and radiative forcing. Our best estimate for net direct and indirect aerosol radiative forcing change is -0.56 W/m{sup 2} between 1750 and 2000. However, the direct and indirect aerosol effects are very sensitive to the black and organic carbon size distribution and consequential mixing state. The net radiative forcing change can vary between -0.32 to -0.75 W/m{sup 2} depending on these carbonaceous particle properties. Assuming that sulfates, nitrates and secondary organics form a coating shell around a black carbon core, rather than forming a uniformly mixed particles, changes the overall net radiative forcing from a negative to a positive number. Black carbon mitigation scenarios showed generally a benefit when mainly black carbon sources such as diesel emissions are reduced, reducing organic and black carbon sources such as bio-fuels, does not lead to reduced warming.

  6. Cirrus and aerosol lidar profilometer - analysis and results

    SciTech Connect (OSTI)

    Spinhirne, J.D.; Scott, V.S.; Reagan, J.A.; Galbraith, A.

    1996-04-01

    A cloud and aerosol lidar set from over a year of near continuous operation of a micro pulse lidar (MPL) instrument at the Cloud and Radiation Testbed (CART) site has been established. MPL instruments are to be included in the Ames Research Center (ARC) instrument compliments for the SW Pacific and Arctic ARM sites. Operational processing algorithms are in development for the data sets. The derived products are to be cloud presence and classification, base height, cirrus thickness, cirrus optical thickness, cirrus extinction profile, aerosol optical thickness and profile, and planetary boundary layer (PBL) height. A cloud presence and base height algorithm is in use, and a data set from the CART site is available. The scientific basis for the algorithm development of the higher level data products and plans for implementation are discussed.

  7. Observations of the first aerosol indirect effect in shallow cumuli

    SciTech Connect (OSTI)

    Berg, Larry K.; Berkowitz, Carl M.; Barnard, James C.; Senum, Gunar; Springston, Stephen R.

    2011-02-08

    Data from the Cumulus Humilis Aerosol Processing Study (CHAPS) are used to estimate the impact of both aerosol indirect effects and cloud dynamics on the microphysical and optical properties of shallow cumuli observed in the vicinity of Oklahoma City, Oklahoma. Not surprisingly, we find that the amount of light scattered by the clouds is dominated by their liquid water content (LWC), which in turn is driven by cloud dynamics. However, removing the effect of cloud dynamics by examining the scattering normalized by LWC shows a strong sensitivity of scattering to pollutant loading. These results suggest that even moderately sized cities, like Oklahoma City, can have a measureable impact on the optical properties of shallow cumuli.

  8. Boundary Layer The U.S. Department of Energy's Atmospheric Radiation

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Aerosol, and Precipitation in the Marine Boundary Layer The U.S. Department of Energy's Atmospheric Radiation Measurement (ARM) Climate Research Facility is sponsoring a 20-month field study on Graciosa Island in the Azores. Scientists involved in the Clouds, Aerosol, and Precipitation in the Marine Boundary Layer field campaign are using the ARM Mobile Facility-a portable climate observatory-to study low-level clouds and aerosol in a marine environment. Collaborators from the Regional

  9. Dispelling Clouds of Uncertainty

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Lewis, Ernie; Teixeira, João

    2015-06-15

    How do you build a climate model that accounts for cloud physics and the transitions between cloud regimes? Use MAGIC.

  10. Indirect and Semi-Direct Aerosol Campaign

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Campaign (ISDAC) The Influence of Arctic Aerosol on Clouds PIs: Steve Ghan, Greg McFarquhar, Hans Verlinde ARM AVP: Beat Schmid, Greg McFarquhar, John Hubbe, Debbie Ronfeld In situ measurements: Sarah Brooks, Don Collins, Dan Cziczo, Manvendra Dubey, Greg Kok, Alexei Korolev, Alex Laskin, Paul Lawson, Peter Liu, Claudio Mazzoleni, Ann-Marie McDonald, Greg McFarquhar, Walter Strapp, Alla Zelenyuk Retrievals: Connor Flynn, Dan Lubin, Mengistu Wolde, David Mitchell, Matthew Shupe, David Turner

  11. Particulate Matter Aerosols

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    particulate matter aerosols Particulate Matter Aerosols The study of atmospheric aerosols is important because of its adverse effects on health, air quality, visibility, cultural heritage, and Earth's radiation balance. Techniques that can help better characterize particulate matter are required to better understand the constituents, causes and sources of particulate matter (PM) aerosols. Carbon is one of the main constituents of atmospheric aerosols. Radiocarbon (14C) measurement performed on

  12. Research Highlight

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ARM Azores Observations Help Identify Deficiencies in Climate Model Simulations of Low Clouds PI Contact: Zheng, X., Lawrence Livermore National Laboratory Area of Research: Cloud Processes Working Group(s): Cloud Life Cycle, Cloud-Aerosol-Precipitation Interactions Journal Reference: Zheng X, SA Klein, H Ma, P Bogenschutz, A Gettelman, and VE Larson. 2016. "Assessment of Marine Boundary Layer Cloud Simulations in the CAM with CLUBB and Updated Microphysics Scheme Based on ARM Observations

  13. Laboratory Experiments and Instrument Intercomparison Studies of Carbonaceous Aerosol Particles

    SciTech Connect (OSTI)

    Davidovits, Paul

    2015-10-20

    Aerosols containing black carbon (and some specific types of organic particulate matter) directly absorb incoming light, heating the atmosphere. In addition, all aerosol particles backscatter solar light, leading to a net-cooling effect. Indirect effects involve hydrophilic aerosols, which serve as cloud condensation nuclei (CCN) that affect cloud cover and cloud stability, impacting both atmospheric radiation balance and precipitation patterns. At night, all clouds produce local warming, but overall clouds exert a net-cooling effect on the Earth. The effect of aerosol radiative forcing on climate may be as large as that of the greenhouse gases, but predominantly opposite in sign and much more uncertain. The uncertainties in the representation of aerosol interactions in climate models makes it problematic to use model projections to guide energy policy. The objective of our program is to reduce the uncertainties in the aerosol radiative forcing in the two areas highlighted in the ASR Science and Program Plan. That is, (1) addressing the direct effect by correlating particle chemistry and morphology with particle optical properties (i.e. absorption, scattering, extinction), and (2) addressing the indirect effect by correlating particle hygroscopicity and CCN activity with particle size, chemistry, and morphology. In this connection we are systematically studying particle formation, oxidation, and the effects of particle coating. The work is specifically focused on carbonaceous particles where the uncertainties in the climate relevant properties are the highest. The ongoing work consists of laboratory experiments and related instrument inter-comparison studies both coordinated with field and modeling studies, with the aim of providing reliable data to represent aerosol processes in climate models. The work is performed in the aerosol laboratory at Boston College. At the center of our laboratory setup are two main sources for the production of aerosol particles: (a

  14. One ARM, Two Columns and a Whole Lot of Aerosols | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    ARM, Two Columns and a Whole Lot of Aerosols One ARM, Two Columns and a Whole Lot of Aerosols July 25, 2012 - 5:49pm Addthis This observatory is part of an air particles research initiative at Cape Cod National Seashore in Massachusetts, and includes dozens of sophisticated instruments that take continuous ground-based measurements of clouds, aerosols, and other atmospheric properties. | Photo courtesy of the ARM Climate Research Facility. This observatory is part of an air particles research

  15. Some results of an experimental study of the atmospheric aerosol in Tomsk: A combined approach

    SciTech Connect (OSTI)

    Zuev, V.V.

    1996-04-01

    As widely accepted, aerosols strongly contribute to the formation of the earth`s radiation balance through the absorption and scattering of solar radiation. In addition, aerosols, being active condensation nuclei, also have a role in the cloud formation process. In this paper, results are presented of aerosol studies undertaken at the field measurement sites of the Institute of Atmospheric Optics in Tomsk and the Tomsk region.

  16. Polluting of Winter Convective Clouds upon Transition from Ocean Inland Over Central California: Contrasting Case Studies

    SciTech Connect (OSTI)

    Rosenfeld, Daniel; Chemke, Rei; Prather, Kimberly; Suski, Kaitlyn; Comstock, Jennifer M.; Schmid, Beat; Tomlinson, Jason M.; Jonsson, Haf

    2014-01-01

    In-situ aircraft measurements of aerosol chemical and cloud microphysical properties were conducted during the CalWater campaign in February and March 2011 over the Sierra Nevada Mountains and the coastal waters of central California. The main objective was to elucidate the impacts of aerosol properties on clouds and precipitation forming processes. In order to accomplish this, we compared contrasting cases of clouds that ingested aerosols from different sources. The results showed that clouds containing pristine oceanic air had low cloud drop concentrations and started to develop rain 500 m above their base. This occurred both over the ocean and over the Sierra Nevada, mainly in the early morning when the radiatively cooled stable continental boundary layer was decoupled from the cloud base. Supercooled rain dominated the precipitation that formed in growing convective clouds in the pristine air, up to the -21C isotherm level. A contrasting situation was documented in the afternoon over the foothills of the Sierra Nevada, when the clouds ingested high pollution aerosol concentrations produced in the Central Valley. This led to slow growth of the cloud drop effective radius with height and suppressed and even prevented the initiation of warm rain while contributing to the development of ice hydrometeors in the form of graupel. Our results show that cloud condensation and ice nuclei were the limiting factors that controlled warm rain and ice processes, respectively, while the unpolluted clouds in the same air mass produced precipitation quite efficiently. These findings provide the motivation for deeper investigations into the nature of the aerosols seeding clouds.

  17. Radiosonde observations at Pt. Reyes and cloud properties retrieved from

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    GOES-WEST Radiosonde observations at Pt. Reyes and cloud properties retrieved from GOES-WEST Inoue, Toshiro MRI/JMA Category: Field Campaigns Low-level cloud formed off the west coast of continents plays an important role in general circulation and climate. Marine Stratus Radiation Aerosol and Drizzle (MASRAD) was conducted at the ARM mobile site deployed at Pt Reyes, California during April to September. Here, we studied the relationship between meteorological parameters observed by GPS

  18. Incorporating an advanced aerosol activation parameterization into WRF-CAM5: Model evaluation and parameterization intercomparison

    SciTech Connect (OSTI)

    Zhang, Yang; Zhang, Xin; Wang, Kai; He, Jian; Leung, Lai-Yung R.; Fan, Jiwen; Nenes, Athanasios

    2015-07-22

    Aerosol activation into cloud droplets is an important process that governs aerosol indirect effects. The advanced treatment of aerosol activation by Fountoukis and Nenes (2005) and its recent updates, collectively called the FN series, have been incorporated into a newly developed regional coupled climate-air quality model based on the Weather Research and Forecasting model with the physics package of the Community Atmosphere Model version 5 (WRF-CAM5) to simulate aerosol-cloud interactions in both resolved and convective clouds. The model is applied to East Asia for two full years of 2005 and 2010. A comprehensive model evaluation is performed for model predictions of meteorological, radiative, and cloud variables, chemical concentrations, and column mass abundances against satellite data and surface observations from air quality monitoring sites across East Asia. The model performs overall well for major meteorological variables including near-surface temperature, specific humidity, wind speed, precipitation, cloud fraction, precipitable water, downward shortwave and longwave radiation, and column mass abundances of CO, SO2, NO2, HCHO, and O3 in terms of both magnitudes and spatial distributions. Larger biases exist in the predictions of surface concentrations of CO and NOx at all sites and SO2, O3, PM2.5, and PM10 concentrations at some sites, aerosol optical depth, cloud condensation nuclei over ocean, cloud droplet number concentration (CDNC), cloud liquid and ice water path, and cloud optical thickness. Compared with the default Abdul-Razzack Ghan (2000) parameterization, simulations with the FN series produce ~107113% higher CDNC, with half of the difference attributable to the higher aerosol activation fraction by the FN series and the remaining half due to feedbacks in subsequent cloud microphysical processes. With the higher CDNC, the FN series are more skillful in simulating cloud water path, cloud optical thickness, downward shortwave radiation

  19. Aerosol mobility size spectrometer

    DOE Patents [OSTI]

    Wang, Jian; Kulkarni, Pramod

    2007-11-20

    A device for measuring aerosol size distribution within a sample containing aerosol particles. The device generally includes a spectrometer housing defining an interior chamber and a camera for recording aerosol size streams exiting the chamber. The housing includes an inlet for introducing a flow medium into the chamber in a flow direction, an aerosol injection port adjacent the inlet for introducing a charged aerosol sample into the chamber, a separation section for applying an electric field to the aerosol sample across the flow direction and an outlet opposite the inlet. In the separation section, the aerosol sample becomes entrained in the flow medium and the aerosol particles within the aerosol sample are separated by size into a plurality of aerosol flow streams under the influence of the electric field. The camera is disposed adjacent the housing outlet for optically detecting a relative position of at least one aerosol flow stream exiting the outlet and for optically detecting the number of aerosol particles within the at least one aerosol flow stream.

  20. ARM - Measurement - Aerosol image

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    would love to hear from you Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Aerosol image Images of aerosols from which one can derive characteristics such...

  1. ARM - Measurement - Aerosol extinction

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Aerosol extinction The removal of radiant energy from an incident beam by the process of aerosol absorption ...

  2. A Multiscale Modeling Framework Model (Superparameterized CAM5) with a Higher-Order Turbulence Closure: Model Description and Low-Cloud Simulations

    SciTech Connect (OSTI)

    Wang, Minghuai; Larson, Vincent E.; Ghan, Steven J.; Ovchinnikov, Mikhail; Schanen, D.; Xiao, Heng; Liu, Xiaohong; Rasch, Philip J.; Guo, Zhun

    2015-06-01

    In this study, a higher-order turbulence closure scheme, called Cloud Layers Unified by Binormals (CLUBB), is implemented into a Multi-scale Modeling Framework (MMF) model to improve low cloud simulations. The performance of CLUBB in MMF simulations with two different microphysics configurations (one-moment cloud microphysics without aerosol treatment and two-moment cloud microphysics coupled with aerosol treatment) is evaluated against observations and further compared with results from the Community Atmosphere Model, Version 5 (CAM5) with conventional cloud parameterizations. CLUBB is found to improve low cloud simulations in the MMF, and the improvement is particularly evident in the stratocumulus-to-cumulus transition regions. Compared to the single-moment cloud microphysics, CLUBB with two-moment microphysics produces clouds that are closer to the coast, and agrees better with observations. In the stratocumulus-to cumulus transition regions, CLUBB with two-moment cloud microphysics produces shortwave cloud forcing in better agreement with observations, while CLUBB with single moment cloud microphysics overestimates shortwave cloud forcing. CLUBB is further found to produce quantitatively similar improvements in the MMF and CAM5, with slightly better performance in the MMF simulations (e.g., MMF with CLUBB generally produces low clouds that are closer to the coast than CAM5 with CLUBB). Improved low cloud simulations in MMF make it an even more attractive tool for studying aerosol-cloud-precipitation interactions.

  3. The Radiative Properties of Small Clouds: Multi-Scale Observations and Modeling

    SciTech Connect (OSTI)

    Feingold, Graham; McComiskey, Allison

    2013-09-25

    Warm, liquid clouds and their representation in climate models continue to represent one of the most significant unknowns in climate sensitivity and climate change. Our project combines ARM observations, LES modeling, and satellite imagery to characterize shallow clouds and the role of aerosol in modifying their radiative effects.

  4. ARM - Measurement - Aerosol scattering

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    : Nephelometer PASS : Photoacoustic Soot Spectrometer RL : Raman Lidar TDMA : Tandem Differential Mobility Analyzer Field Campaign Instruments AMT : Aerosol Modeling...

  5. Aerosol Extinction Profiles

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and Thermodynamic Responses to Uncertainty in Aerosol Extinction Profiles For original submission and image(s), see ARM Research Highlights http://www.arm.gov/science/highlights/ Research Highlight Aerosol radiative effects are of great importance for climate simulations over South Asia. For quantifying aerosol direct radiative effect, aerosol optical depth (AOD) and single scattering albedo (SSA) are often compared with observations. These comparisons have revealed large AOD underestimation and

  6. Aerosol distribution apparatus

    DOE Patents [OSTI]

    Hanson, W.D.

    An apparatus for uniformly distributing an aerosol to a plurality of filters mounted in a plenum, wherein the aerosol and air are forced through a manifold system by means of a jet pump and released into the plenum through orifices in the manifold. The apparatus allows for the simultaneous aerosol-testing of all the filters in the plenum.

  7. Solid aerosol generator

    DOE Patents [OSTI]

    Prescott, Donald S.; Schober, Robert K.; Beller, John

    1992-01-01

    An improved solid aerosol generator used to produce a gas borne stream of dry, solid particles of predetermined size and concentration. The improved solid aerosol generator nebulizes a feed solution of known concentration with a flow of preheated gas and dries the resultant wet heated aerosol in a grounded, conical heating chamber, achieving high recovery and flow rates.

  8. Improved solid aerosol generator

    DOE Patents [OSTI]

    Prescott, D.S.; Schober, R.K.; Beller, J.

    1988-07-19

    An improved solid aerosol generator used to produce a gas borne stream of dry, solid particles of predetermined size and concentration. The improved solid aerosol generator nebulizes a feed solution of known concentration with a flow of preheated gas and dries the resultant wet heated aerosol in a grounded, conical heating chamber, achieving high recovery and flow rates. 2 figs.

  9. Solid aerosol generator

    DOE Patents [OSTI]

    Prescott, D.S.; Schober, R.K.; Beller, J.

    1992-03-17

    An improved solid aerosol generator used to produce a gas borne stream of dry, solid particles of predetermined size and concentration is disclosed. The improved solid aerosol generator nebulizes a feed solution of known concentration with a flow of preheated gas and dries the resultant wet heated aerosol in a grounded, conical heating chamber, achieving high recovery and flow rates. 2 figs.

  10. Atmospheric Radiation Measurment (ARM) Data from the Ganges Valley, India for the Ganges Valley Aerosol Experiment (GVAX)

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    In 2011 and 2012, the Ganges Valley Aerosol Experiment (GVAX) began in the Ganges Valley region of India. The objective was to obtain measurements of clouds, precipitation, and complex aerosols to study their impact on cloud formation and monsoon activity in the region. During the Indian Ocean Experiment (INDOEX) field studies, aerosols from the Ganges Valley region were shown to affect cloud formation and monsoon activity over the Indian Ocean. The complex field study used the ARM Mobile Facility (AMF) to measure radiative, cloud, convection, and aerosol characteristics over the mainland. The resulting data set captured pre-monsoon to post-monsoon conditions to establish a comprehensive baseline for advancements in the study of the effects of atmospheric conditions of the Ganges Valley.

  11. In the OSTI Collections: Clouds, Sunlight, and Radiant Heat | OSTI, US Dept

    Office of Scientific and Technical Information (OSTI)

    of Energy Office of Scientific and Technical Information Clouds, Sunlight, and Radiant Heat View Past"In the OSTI Collections"Articles. Article Acknowledgement: Dr. William N. Watson, Physicist DOE Office of Scientific and Technical Information Clouds and other aerosols More about clouds Plans for further investigations References Reports available through OSTI's SciTech Connect Additional references The sun radiates electromagnetic waves of every frequency into the space around

  12. Intercomparison of the Cloud Water Phase among Global Climate Models

    SciTech Connect (OSTI)

    Komurcu, Muge; Storelvmo, Trude; Tan, Ivy; Lohmann, U.; Yun, Yuxing; Penner, Joyce E.; Wang, Yong; Liu, Xiaohong; Takemura, T.

    2014-03-27

    Mixed-phase clouds (clouds that consist of both cloud droplets and ice crystals) are frequently present in the Earths atmosphere and influence the Earths energy budget through their radiative properties, which are highly dependent on the cloud water phase. In this study, the phase partitioning of cloud water is compared among six global climate models (GCMs) and with Cloud and Aerosol Lidar with Orthogonal Polarization retrievals. It is found that the GCMs predict vastly different distributions of cloud phase for a given temperature, and none of them are capable of reproducing the spatial distribution or magnitude of the observed phase partitioning. While some GCMs produced liquid water paths comparable to satellite observations, they all failed to preserve sufficient liquid water at mixed-phase cloud temperatures. Our results suggest that validating GCMs using only the vertically integrated water contents could lead to amplified differences in cloud radiative feedback. The sensitivity of the simulated cloud phase in GCMs to the choice of heterogeneous ice nucleation parameterization is also investigated. The response to a change in ice nucleation is quite different for each GCM, and the implementation of the same ice nucleation parameterization in all models does not reduce the spread in simulated phase among GCMs. The results suggest that processes subsequent to ice nucleation are at least as important in determining phase and should be the focus of future studies aimed at understanding and reducing differences among the models.

  13. Dispelling Clouds of Uncertainty

    SciTech Connect (OSTI)

    Lewis, Ernie; Teixeira, João

    2015-06-15

    How do you build a climate model that accounts for cloud physics and the transitions between cloud regimes? Use MAGIC.

  14. ARM - Measurement - Cloud location

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    point in space and time, typically expressed as a binary cloud mask. Categories Cloud Properties Instruments The above measurement is considered scientifically relevant for the...

  15. Macquarie Island Cloud and Radiation Experiment (MICRE) Science Plan

    SciTech Connect (OSTI)

    Marchand, RT; Protat, A; Alexander, SP

    2015-12-01

    Clouds over the Southern Ocean are poorly represented in present day reanalysis products and global climate model simulations. Errors in top-of-atmosphere (TOA) broadband radiative fluxes in this region are among the largest globally, with large implications for modeling both regional and global scale climate responses (e.g., Trenberth and Fasullo 2010, Ceppi et al. 2012). Recent analyses of model simulations suggest that model radiative errors in the Southern Ocean are due to a lack of low-level postfrontal clouds (including clouds well behind the front) and perhaps a lack of supercooled liquid water that contribute most to the model biases (Bodas-Salcedo et al. 2013, Huang et al. 2014). These assessments of model performance, as well as our knowledge of cloud and aerosol properties over the Southern Ocean, rely heavily on satellite data sets. Satellite data sets are incomplete in that the observations are not continuous (i.e., they are acquired only when the satellite passes nearby), generally do not sample the diurnal cycle, and view primarily the tops of cloud systems (especially for the passive instruments). This is especially problematic for retrievals of aerosol, low-cloud properties, and layers of supercooled water embedded within (rather than at the top of) clouds, as well as estimates of surface shortwave and longwave fluxes based on these properties.

  16. Aerosol indirect effects -- general circulation model intercomparison and evaluation with satellite data

    SciTech Connect (OSTI)

    Quaas, Johannes; Ming, Yi; Menon, Surabi; Takemura, Toshihiko; Wang, Minghuai; Penner, Joyce E.; Gettelman, Andrew; Lohmann, Ulrike; Bellouin, Nicolas; Boucher, Olivier; Sayer, Andrew M.; Thomas, Gareth E.; McComiskey, Allison; Feingold, Graham; Hoose, Corinna; Kristjansson, Jon Egill; Liu, Xiaohong; Balkanski, Yves; Donner, Leo J.; Ginoux, Paul A.; Stier, Philip; Feichter, Johann; Sednev, Igor; Bauer, Susanne E.; Koch, Dorothy; Grainger, Roy G.; Kirkevag, Alf; Iversen, Trond; Seland, Oyvind; Easter, Richard; Ghan, Steven J.; Rasch, Philip J.; Morrison, Hugh; Lamarque, Jean-Francois; Iacono, Michael J.; Kinne, Stefan; Schulz, Michael

    2009-04-10

    Aerosol indirect effects continue to constitute one of the most important uncertainties for anthropogenic climate perturbations. Within the international AEROCOM initiative, the representation of aerosol-cloud-radiation interactions in ten different general circulation models (GCMs) is evaluated using three satellite datasets. The focus is on stratiform liquid water clouds since most GCMs do not include ice nucleation effects, and none of the model explicitly parameterizes aerosol effects on convective clouds. We compute statistical relationships between aerosol optical depth (Ta) and various cloud and radiation quantities in a manner that is consistent between the models and the satellite data. It is found that the model-simulated influence of aerosols on cloud droplet number concentration (Nd) compares relatively well to the satellite data at least over the ocean. The relationship between Ta and liquid water path is simulated much too strongly by the models. It is shown that this is partly related to the representation of the second aerosol indirect effect in terms of autoconversion. A positive relationship between total cloud fraction (fcld) and Ta as found in the satellite data is simulated by the majority of the models, albeit less strongly than that in the satellite data in most of them. In a discussion of the hypotheses proposed in the literature to explain the satellite-derived strong fcld - Ta relationship, our results indicate that none can be identified as unique explanation. Relationships similar to the ones found in satellite data between Ta and cloud top temperature or outgoing long-wave radiation (OLR) are simulated by only a few GCMs. The GCMs that simulate a negative OLR - Ta relationship show a strong positive correlation between Ta and fcld The short-wave total aerosol radiative forcing as simulated by the GCMs is strongly influenced by the simulated anthropogenic fraction of Ta, and parameterisation assumptions such as a lower bound on Nd

  17. Cirrus clouds in a global climate model with a statistical cirrus cloud scheme

    SciTech Connect (OSTI)

    Wang, Minghuai; Penner, Joyce E.

    2010-06-21

    A statistical cirrus cloud scheme that accounts for mesoscale temperature perturbations is implemented in a coupled aerosol and atmospheric circulation model to better represent both subgrid-scale supersaturation and cloud formation. This new scheme treats the effects of aerosol on cloud formation and ice freezing in an improved manner, and both homogeneous freezing and heterogeneous freezing are included. The scheme is able to better simulate the observed probability distribution of relative humidity compared to the scheme that was implemented in an older version of the model. Heterogeneous ice nuclei (IN) are shown to decrease the frequency of occurrence of supersaturation, and improve the comparison with observations at 192 hPa. Homogeneous freezing alone can not reproduce observed ice crystal number concentrations at low temperatures (<205 K), but the addition of heterogeneous IN improves the comparison somewhat. Increases in heterogeneous IN affect both high level cirrus clouds and low level liquid clouds. Increases in cirrus clouds lead to a more cloudy and moist lower troposphere with less precipitation, effects which we associate with the decreased convective activity. The change in the net cloud forcing is not very sensitive to the change in ice crystal concentrations, but the change in the net radiative flux at the top of the atmosphere is still large because of changes in water vapor. Changes in the magnitude of the assumed mesoscale temperature perturbations by 25% alter the ice crystal number concentrations and the net radiative fluxes by an amount that is comparable to that from a factor of 10 change in the heterogeneous IN number concentrations. Further improvements on the representation of mesoscale temperature perturbations, heterogeneous IN and the competition between homogeneous freezing and heterogeneous freezing are needed.

  18. RACORO continental boundary layer cloud investigations. 2. Large-eddy simulations of cumulus clouds and evaluation with in-situ and ground-based observations

    SciTech Connect (OSTI)

    Endo, Satoshi; Fridlind, Ann M.; Lin, Wuyin; Vogelmann, Andrew M.; Toto, Tami; Ackerman, Andrew S.; McFarquhar, Greg M.; Jackson, Robert C.; Jonsson, Haflidi H.; Liu, Yangang

    2015-06-19

    A 60-hour case study of continental boundary layer cumulus clouds is examined using two large-eddy simulation (LES) models. The case is based on observations obtained during the RACORO Campaign (Routine Atmospheric Radiation Measurement [ARM] Aerial Facility [AAF] Clouds with Low Optical Water Depths [CLOWD] Optical Radiative Observations) at the ARM Climate Research Facility's Southern Great Plains site. The LES models are driven by continuous large-scale and surface forcings, and are constrained by multi-modal and temporally varying aerosol number size distribution profiles derived from aircraft observations. We compare simulated cloud macrophysical and microphysical properties with ground-based remote sensing and aircraft observations. The LES simulations capture the observed transitions of the evolving cumulus-topped boundary layers during the three daytime periods, and generally reproduce variations of droplet number concentration with liquid water content (LWC), corresponding to the gradient between the cloud centers and cloud edges at given heights. The observed LWC values fall within the range of simulated values; the observed droplet number concentrations are commonly higher than simulated, but differences remain on par with potential estimation errors in the aircraft measurements. Sensitivity studies examine the influences of bin microphysics versus bulk microphysics, aerosol advection, supersaturation treatment, and aerosol hygroscopicity. Simulated macrophysical cloud properties are found to be insensitive in this non-precipitating case, but microphysical properties are especially sensitive to bulk microphysics supersaturation treatment and aerosol hygroscopicity.

  19. RACORO continental boundary layer cloud investigations. 2. Large-eddy simulations of cumulus clouds and evaluation with in-situ and ground-based observations

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Endo, Satoshi; Fridlind, Ann M.; Lin, Wuyin; Vogelmann, Andrew M.; Toto, Tami; Ackerman, Andrew S.; McFarquhar, Greg M.; Jackson, Robert C.; Jonsson, Haflidi H.; Liu, Yangang

    2015-06-19

    A 60-hour case study of continental boundary layer cumulus clouds is examined using two large-eddy simulation (LES) models. The case is based on observations obtained during the RACORO Campaign (Routine Atmospheric Radiation Measurement [ARM] Aerial Facility [AAF] Clouds with Low Optical Water Depths [CLOWD] Optical Radiative Observations) at the ARM Climate Research Facility's Southern Great Plains site. The LES models are driven by continuous large-scale and surface forcings, and are constrained by multi-modal and temporally varying aerosol number size distribution profiles derived from aircraft observations. We compare simulated cloud macrophysical and microphysical properties with ground-based remote sensing and aircraft observations.more » The LES simulations capture the observed transitions of the evolving cumulus-topped boundary layers during the three daytime periods, and generally reproduce variations of droplet number concentration with liquid water content (LWC), corresponding to the gradient between the cloud centers and cloud edges at given heights. The observed LWC values fall within the range of simulated values; the observed droplet number concentrations are commonly higher than simulated, but differences remain on par with potential estimation errors in the aircraft measurements. Sensitivity studies examine the influences of bin microphysics versus bulk microphysics, aerosol advection, supersaturation treatment, and aerosol hygroscopicity. Simulated macrophysical cloud properties are found to be insensitive in this non-precipitating case, but microphysical properties are especially sensitive to bulk microphysics supersaturation treatment and aerosol hygroscopicity.« less

  20. RACORO Extended-Term Aircraft Observations of Boundary-Layer Clouds

    SciTech Connect (OSTI)

    Vogelmann, A. M.; McFarquhar, Greg; Ogren, John A.; Turner, David D.; Comstock, Jennifer M.; Feingold, G.; Long, Charles N.; Jonsson, Haf; Bucholtz, Anthony; Collins, Donald R.; Diskin, G. S.; Gerber, H.; Lawson, Paul; Woods, Roy; Andrews, Elizabeth; Yang, Hee-Jung; Chiu, Christine J.; Hartsock, Daniel; Hubbe, John M.; Lo, Chaomei; Marshak, A.; Monroe, Justin; McFarlane, Sally A.; Schmid, Beat; Tomlinson, Jason M.; Toto, Tami

    2012-06-30

    A first-of-a-kind, extended-term cloud aircraft campaign was conducted to obtain an in-situ statistical characterization of boundary-layer clouds needed to investigate cloud processes and refine retrieval algorithms. Coordinated by the Atmospheric Radiation Measurement (ARM) Aerial Facility (AAF), the Routine AAF Clouds with Low Optical Water Depths (CLOWD) Optical Radiative Observations (RACORO) field campaign operated over the ARM Southern Great Plains (SGP) site from 22 January to 30 June 2009, collecting 260 h of data during 59 research flights. A comprehensive payload aboard the Center for Interdisciplinary Remotely-Piloted Aircraft Studies (CIRPAS) Twin Otter aircraft measured cloud microphysics, solar and thermal radiation, aerosol properties, and atmospheric state parameters. Proximity to the SGP's extensive complement of surface measurements provides ancillary data that supports modeling studies and enables evaluating a variety of surface retrieval algorithms. The five-month duration enabled sampling a range of conditions associated with the seasonal transition from winter to summer. Although about two-thirds of the cloud flights occurred in May and June, boundary-layer cloud fields were sampled under a variety of environmental and aerosol conditions, with about 75% of the flights occurring in cumulus and stratocumulus. Preliminary analyses show how these data are being used to analyze cloud-aerosol relationships, determine the aerosol sizes that are responsible for nucleating cloud drops, characterize the horizontal variability of the cloud radiative impacts, and evaluate air-borne and surface-based cloud property retrievals. We discuss how conducting an extended-term campaign requires a simplified operating paradigm that is different from that used for typical, short-term, intensive aircraft field programs.

  1. Aerosol specification in single-column Community Atmosphere Model version 5

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Lebassi-Habtezion, B.; Caldwell, P. M.

    2015-03-27

    Single-column model (SCM) capability is an important tool for general circulation model development. In this study, the SCM mode of version 5 of the Community Atmosphere Model (CAM5) is shown to handle aerosol initialization and advection improperly, resulting in aerosol, cloud-droplet, and ice crystal concentrations which are typically much lower than observed or simulated by CAM5 in global mode. This deficiency has a major impact on stratiform cloud simulations but has little impact on convective case studies because aerosol is currently not used by CAM5 convective schemes and convective cases are typically longer in duration (so initialization is less important).more » By imposing fixed aerosol or cloud-droplet and crystal number concentrations, the aerosol issues described above can be avoided. Sensitivity studies using these idealizations suggest that the Meyers et al. (1992) ice nucleation scheme prevents mixed-phase cloud from existing by producing too many ice crystals. Microphysics is shown to strongly deplete cloud water in stratiform cases, indicating problems with sequential splitting in CAM5 and the need for careful interpretation of output from sequentially split climate models. Droplet concentration in the general circulation model (GCM) version of CAM5 is also shown to be far too low (~ 25 cm−3) at the southern Great Plains (SGP) Atmospheric Radiation Measurement (ARM) site.« less

  2. Implementing marine organic aerosols into the GEOS-Chem model

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Gantt, B.; Johnson, M. S.; Crippa, M.; Prévôt, A. S. H.; Meskhidze, N.

    2014-09-09

    Marine organic aerosols (MOA) have been shown to play an important role in tropospheric chemistry by impacting surface mass, cloud condensation nuclei, and ice nuclei concentrations over remote marine and coastal regions. In this work, an online marine primary organic aerosol emission parameterization, designed to be used for both global and regional models, was implemented into the GEOS-Chem model. The implemented emission scheme improved the large underprediction of organic aerosol concentrations in clean marine regions (normalized mean bias decreases from -79% when using the default settings to -12% when marine organic aerosols are added). Model predictions were also in goodmore » agreement (correlation coefficient of 0.62 and normalized mean bias of -36%) with hourly surface concentrations of MOA observed during the summertime at an inland site near Paris, France. Our study shows that MOA have weaker coastal-to-inland concentration gradients than sea-salt aerosols, leading to several inland European cities having > 10% of their surface submicron organic aerosol mass concentration with a marine source. The addition of MOA tracers to GEOS-Chem enabled us to identify the regions with large contributions of freshly-emitted or aged aerosol having distinct physicochemical properties, potentially indicating optimal locations for future field studies.« less

  3. Implementing marine organic aerosols into the GEOS-Chem model

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Gantt, B.; Johnson, M. S.; Crippa, M.; Prévôt, A. S. H.; Meskhidze, N.

    2015-03-17

    Marine-sourced organic aerosols (MOAs) have been shown to play an important role in tropospheric chemistry by impacting surface mass, cloud condensation nuclei, and ice nuclei concentrations over remote marine and coastal regions. In this work, an online marine primary organic aerosol emission parameterization, designed to be used for both global and regional models, was implemented into the GEOS-Chem (Global Earth Observing System Chemistry) model. The implemented emission scheme improved the large underprediction of organic aerosol concentrations in clean marine regions (normalized mean bias decreases from -79% when using the default settings to -12% when marine organic aerosols are added). Modelmore » predictions were also in good agreement (correlation coefficient of 0.62 and normalized mean bias of -36%) with hourly surface concentrations of MOAs observed during the summertime at an inland site near Paris, France. Our study shows that MOAs have weaker coastal-to-inland concentration gradients than sea-salt aerosols, leading to several inland European cities having >10% of their surface submicron organic aerosol mass concentration with a marine source. The addition of MOA tracers to GEOS-Chem enabled us to identify the regions with large contributions of freshly emitted or aged aerosol having distinct physicochemical properties, potentially indicating optimal locations for future field studies.« less

  4. Aerosol specification in single-column CAM5

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Lebassi-Habtezion, B.; Caldwell, P.

    2014-11-17

    The ability to run a global climate model in single-column mode is very useful for testing model improvements because single-column models (SCMs) are inexpensive to run and easy to interpret. A major breakthrough in Version 5 of the Community Atmosphere Model (CAM5) is the inclusion of prognostic aerosol. Unfortunately, this improvement was not coordinated with the SCM version of CAM5 and as a result CAM5-SCM initializes aerosols to zero. In this study we explore the impact of running CAM5-SCM with aerosol initialized to zero (hereafter named Default) and test three potential fixes. The first fix is to use CAM5's prescribedmore » aerosol capability, which specifies aerosols at monthly climatological values. The second method is to prescribe aerosols at observed values. The third approach is to fix droplet and ice crystal numbers at prescribed values. We test our fixes in four different cloud regimes to ensure representativeness: subtropical drizzling stratocumulus (based on the DYCOMS RF02 case study), mixed-phase Arctic stratocumulus (using the MPACE-B case study), tropical shallow convection (using the RICO case study), and summertime mid-latitude continental convection (using the ARM95 case study). Stratiform cloud cases (DYCOMS RF02 and MPACE-B) were found to have a strong dependence on aerosol concentration, while convective cases (RICO and ARM95) were relatively insensitive to aerosol specification. This is perhaps expected because convective schemes in CAM5 do not currently use aerosol information. Adequate liquid water content in the MPACE-B case was only maintained when ice crystal number concentration was specified because the Meyers et al. (1992) deposition/condensation ice nucleation scheme used by CAM5 greatly overpredicts ice nucleation rates, causing clouds to rapidly glaciate. Surprisingly, predicted droplet concentrations for the ARM95 region in both SCM and global runs were around 25 cm−3, which is much lower than observed. This finding

  5. On the characteristics of aerosol indirect effect based on dynamic regimes in global climate models

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Zhang, S.; Wang, M.; Ghan, S. J.; Ding, A.; Wang, H.; Zhang, K.; Neubauer, D.; Lohmann, U.; Ferrachat, S.; Takeamura, T.; et al

    2015-09-02

    Aerosol-cloud interactions continue to constitute a major source of uncertainty for the estimate of climate radiative forcing. The variation of aerosol indirect effects (AIE) in climate models is investigated across different dynamical regimes, determined by monthly mean 500 hPa vertical pressure velocity (?500), lower-tropospheric stability (LTS) and large-scale surface precipitation rate derived from several global climate models (GCMs), with a focus on liquid water path (LWP) response to cloud condensation nuclei (CCN) concentrations. The LWP sensitivity to aerosol perturbation within dynamic regimes is found to exhibit a large spread among these GCMs. It is in regimes of strong large-scale ascendmore(?500 ?1) and low clouds (stratocumulus and trade wind cumulus) where the models differ most. Shortwave aerosol indirect forcing is also found to differ significantly among different regimes. Shortwave aerosol indirect forcing in ascending regimes is as large as that in stratocumulus regimes, which indicates that regimes with strong large-scale ascend are as important as stratocumulus regimes in studying AIE. It is further shown that shortwave aerosol indirect forcing over regions with high monthly large-scale surface precipitation rate (> 0.1 mm d?1) contributes the most to the total aerosol indirect forcing (from 64 to nearly 100 %). Results show that the uncertainty in AIE is even larger within specific dynamical regimes than that globally, pointing to the need to reduce the uncertainty in AIE in different dynamical regimes.less

  6. Science Cloud 2011

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Science Cloud 2011 Science Cloud 2011 June 17, 2011 The Magellan teams at NERSC and Argonne recently presented a joint paper detailing their progress and conclusions. At Science Cloud 2011: The Second Workshop on Scientific Cloud Computing, in a paper titled "Magellan: Experiences from a Science Cloud" (PDF, 320KB), lead author Lavanya Ramakrishnan outlined the groups' most recent achievements and conclusions, including a successful run of real-time data analysis for the STAR

  7. Effect of Aerosol Humidification on the Column Aerosol Optical...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    of Aerosol Humidification on the Column Aerosol Optical Thickness over the ARM Southern Great Plains Site Li, Zhanqing University of Maryland Jeong, Myeong-Jae University of...

  8. Two-Column Aerosol Project

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Column Aerosol Project Tiny particles in the sky known as "aerosols" come in many forms-dust, soot, and sea salt, for example. Depending on the type of aerosol, it can either...

  9. ARM - AOS Aerosol Properties Plots

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    XDC Data Viewers Aerosol Properties Plots SGP AMF NSA (BRW) AOS Aerosol Properties Plots ... are raw unedited data. Do not quote and cite. Aerosol Properties Plots SGP AMF NSA (BRW)

  10. ARM - Measurement - Aerosol composition

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    quality assurance purposes. ARM Instruments PILS : Particle Into Liquid Sampler TDMA : Tandem Differential Mobility Analyzer Field Campaign Instruments AEROSMASSSPEC : Aerosol Mass...

  11. Atmospheric Radiation Measurement (ARM) Data from Point Reyes, California for the Marine Stratus, Radiation, Aerosol, and Drizzle (MASRAD) Project

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Point Reyes National Seashore, on the California coast north of San Francisco, was the location of the first deployment of the DOE's Atmospheric Radiation Measurement (ARM) Mobile Facility (AMF). The ARM Program collaborated with the U.S. Office of Naval Research and DOE's Aerosol Science Program in the Marine Stratus, Radiation, Aerosol, and Drizzle (MASRAD) project. Their objectives were to collect data from cloud/aerosol interactions and to improve understanding of cloud organization that is often associated with patches of drizzle. Between March and September 2005, the AMF and at least two research aircraft were used to collect data.

  12. Distinguishing Aerosol Impacts on Climate Over the Past Century

    SciTech Connect (OSTI)

    Koch, Dorothy; Menon, Surabi; Del Genio, Anthony; Ruedy, Reto; Alienov, Igor; Schmidt, Gavin A.

    2008-08-22

    Aerosol direct (DE), indirect (IE), and black carbon-snow albedo (BAE) effects on climate between 1890 and 1995 are compared using equilibrium aerosol-climate simulations in the Goddard Institute for Space Studies General Circulation Model coupled to a mixed layer ocean. Pairs of control(1890)-perturbation(1995) with successive aerosol effects allow isolation of each effect. The experiments are conducted both with and without concurrent changes in greenhouse gases (GHG's). A new scheme allowing dependence of snow albedo on black carbon snow concentration is introduced. The fixed GHG experiments global surface air temperature (SAT) changed -0.2, -1.0 and +0.2 C from the DE, IE, and BAE. Ice and snow cover increased 1.0% from the IE and decreased 0.3% from the BAE. These changes were a factor of 4 larger in the Arctic. Global cloud cover increased by 0.5% from the IE. Net aerosol cooling effects are about half as large as the GHG warming, and their combined climate effects are smaller than the sum of their individual effects. Increasing GHG's did not affect the IE impact on cloud cover, however they decreased aerosol effects on SAT by 20% and on snow/ice cover by 50%; they also obscure the BAE on snow/ice cover. Arctic snow, ice, cloud, and shortwave forcing changes occur mostly during summer-fall, but SAT, sea level pressure, and long-wave forcing changes occur during winter. An explanation is that aerosols impact the cryosphere during the warm-season but the associated SAT effect is delayed until winter.

  13. ARM - Measurement - Aerosol optical properties

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    : Aerosol optical properties The optical properties of aerosols, including asymmetry factor, phase-function, single-scattering albedo, refractive index, and backscatter...

  14. Final Project Report - ARM CLASIC CIRPAS Twin Otter Aerosol

    SciTech Connect (OSTI)

    John A. Ogren

    2010-04-05

    The NOAA/ESRL/GMD aerosol group made three types of contributions related to airborne measurements of aerosol light scattering and absorption for the Cloud and Land Surface Interaction Campaign (CLASIC) in June 2007 on the Twin Otter research airplane operated by the Center for Interdisciplinary Remotely-Piloted Aircraft Studies (CIRPAS). GMD scientists served as the instrument mentor for the integrating nephelometer and particle soot absorption photometer (PSAP) on the Twin Otter during CLASIC, and were responsible for (1) instrument checks/comparisons; (2) instrument trouble shooting/repair; and (3) data quality control (QC) and submittal to the archive.

  15. Cloud Properties Working Group Low Clouds Update

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Cloud Properties Working Group Low Clouds Update Low Clouds Update Jennifer Comstock Jennifer Comstock Dave Turner Dave Turner Andy Andy Vogelmann Vogelmann Instruments Instruments 90/150 GHz microwave radiometer 90/150 GHz microwave radiometer Deployed during COPS AMF Deployed during COPS AMF Exploring calibration w/ DPR ( Exploring calibration w/ DPR ( Crewell Crewell & & L L ö ö hnert hnert ) ) See COPS Breakout, Wednesday evening See COPS Breakout, Wednesday evening 183 GHz (GVR)

  16. Cloud Effects on Radiative Heating Rate Profiles over Darwin using ARM and A-train Radar/Lidar Observations

    SciTech Connect (OSTI)

    Thorsen, Tyler J.; Fu, Qiang; Comstock, Jennifer M.

    2013-06-11

    Observations of clouds from the ground-based U.S. Department of Energy Atmospheric Radiation Measurement program (ARM) and satellite-based A-train are used to compute cloud radiative forcing profiles over the ARM Darwin, Australia site. Cloud properties are obtained from both radar (the ARM Millimeter Cloud Radar (MMCR) and the CloudSat satellite in the A-train) and lidar (the ARM Micropulse lidar (MPL) and the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) satellite in the A-train) observations. Cloud microphysical properties are taken from combined radar and lidar retrievals for ice clouds and radar only or lidar only retrievals for liquid clouds. Large, statistically significant differences of up to 1.43 K/day exist between the mean ARM and A-train net cloud radiative forcing profiles. The majority of the difference in cloud radiative forcing profiles is shown to be due to a large difference in the cloud fraction above 12 km. Above this altitude the A-train cloud fraction is significantly larger because more clouds are detected by CALIPSO than by the ground-based MPL. It is shown that the MPL is unable to observe as many high clouds as CALIPSO due to being more frequently attenuated and a poorer sensitivity even in otherwise clear-sky conditions. After accounting for cloud fraction differences and instrument sampling differences due to viewing platform we determined that differences in cloud radiative forcing due to the retrieved ice cloud properties is relatively small. This study demonstrates that A-train observations are better suited for the calculation cloud radiative forcing profiles. In addition, we find that it is necessary to supplement CloudSat with CALIPSO observations to obtain accurate cloud radiative forcing profiles since a large portion of clouds at Darwin are detected by CALIPSO only.

  17. Direct Aerosol Forcing Uncertainty

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Mccomiskey, Allison

    2008-01-15

    Understanding sources of uncertainty in aerosol direct radiative forcing (DRF), the difference in a given radiative flux component with and without aerosol, is essential to quantifying changes in Earth's radiation budget. We examine the uncertainty in DRF due to measurement uncertainty in the quantities on which it depends: aerosol optical depth, single scattering albedo, asymmetry parameter, solar geometry, and surface albedo. Direct radiative forcing at the top of the atmosphere and at the surface as well as sensitivities, the changes in DRF in response to unit changes in individual aerosol or surface properties, are calculated at three locations representing distinct aerosol types and radiative environments. The uncertainty in DRF associated with a given property is computed as the product of the sensitivity and typical measurement uncertainty in the respective aerosol or surface property. Sensitivity and uncertainty values permit estimation of total uncertainty in calculated DRF and identification of properties that most limit accuracy in estimating forcing. Total uncertainties in modeled local diurnally averaged forcing range from 0.2 to 1.3 W m-2 (42 to 20%) depending on location (from tropical to polar sites), solar zenith angle, surface reflectance, aerosol type, and aerosol optical depth. The largest contributor to total uncertainty in DRF is usually single scattering albedo; however decreasing measurement uncertainties for any property would increase accuracy in DRF. Comparison of two radiative transfer models suggests the contribution of modeling error is small compared to the total uncertainty although comparable to uncertainty arising from some individual properties.

  18. Portable Aerosol Contaminant Extractor

    DOE Patents [OSTI]

    Carlson, Duane C.; DeGange, John J.; Cable-Dunlap, Paula

    2005-11-15

    A compact, portable, aerosol contaminant extractor having ionization and collection sections through which ambient air may be drawn at a nominal rate so that aerosol particles ionized in the ionization section may be collected on charged plate in the collection section, the charged plate being readily removed for analyses of the particles collected thereon.

  19. Aerosol Radiative Forcing Under Cloudless Conditions.in Winter ZCAREX-2001

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Forcing Under Cloudless Conditions in Winter ZCAREX-2001 G. S. Golitsyn, I. A. Gorchakova, and I. I. Mokhov Institute of Atmospheric Physic Moscow, Russia Introduction Aerosol radiative forcing (ARF) is estimated for winter clear-sky conditions from measurements during ZCAREX-2001-Cloud-Aerosol-Radiation Experiment in February-March, 2001 at the Zvenigorod Scientific Station (ZSS) of the A.M. Obukhov Institute of Atmospheric Physics RAS. ARF in the shortwave range is determined by the difference

  20. Testing cloud microphysics parameterizations in NCAR CAM5 with ISDAC and M-PACE observations

    SciTech Connect (OSTI)

    Liu X.; Lin W.; Xie, S.; Boyle, J.; Klein, S. A.; Shi, X.; Wang, Z.; Ghan, S. J.; Earle, M.; Liu, P. S. K.; Zelenyuk, A.

    2011-12-24

    Arctic clouds simulated by the National Center for Atmospheric Research (NCAR) Community Atmospheric Model version 5 (CAM5) are evaluated with observations from the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Indirect and Semi-Direct Aerosol Campaign (ISDAC) and Mixed-Phase Arctic Cloud Experiment (M-PACE), which were conducted at its North Slope of Alaska site in April 2008 and October 2004, respectively. Model forecasts for the Arctic spring and fall seasons performed under the Cloud-Associated Parameterizations Testbed framework generally reproduce the spatial distributions of cloud fraction for single-layer boundary-layer mixed-phase stratocumulus and multilayer or deep frontal clouds. However, for low-level stratocumulus, the model significantly underestimates the observed cloud liquid water content in both seasons. As a result, CAM5 significantly underestimates the surface downward longwave radiative fluxes by 20-40 W m{sup -2}. Introducing a new ice nucleation parameterization slightly improves the model performance for low-level mixed-phase clouds by increasing cloud liquid water content through the reduction of the conversion rate from cloud liquid to ice by the Wegener-Bergeron-Findeisen process. The CAM5 single-column model testing shows that changing the instantaneous freezing temperature of rain to form snow from -5 C to -40 C causes a large increase in modeled cloud liquid water content through the slowing down of cloud liquid and rain-related processes (e.g., autoconversion of cloud liquid to rain). The underestimation of aerosol concentrations in CAM5 in the Arctic also plays an important role in the low bias of cloud liquid water in the single-layer mixed-phase clouds. In addition, numerical issues related to the coupling of model physics and time stepping in CAM5 are responsible for the model biases and will be explored in future studies.

  1. ARM - Measurement - Cloud extinction

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Cloud extinction The removal of radiant energy from an incident beam by the process of cloud absorption andor ...

  2. METHANE GAS STABILIZES SUPERCOOLED ETHANE DROPLETS IN TITAN'S CLOUDS

    SciTech Connect (OSTI)

    Wang, Chia C.; Lang, E. Kathrin; Signorell, Ruth

    2010-03-20

    Strong evidence for ethane clouds in various regions of Titan's atmosphere has recently been found. Ethane is usually assumed to exist as ice particles in these clouds, although the possible role of liquid and supercooled liquid ethane droplets has been recognized. Here, we report on infrared spectroscopic measurements of ethane aerosols performed in the laboratory under conditions mimicking Titan's lower atmosphere. The results clearly show that liquid ethane droplets are significantly stabilized by methane gas which is ubiquitous in Titan's nitrogen atmosphere-a phenomenon that does not have a counterpart for water droplets in Earth's atmosphere. Our data imply that supercooled ethane droplets are much more abundant in Titan's clouds than previously anticipated. Possibly, these liquid droplets are even more important for cloud processes and the formation of lakes than ethane ice particles.

  3. MAGIC: Marine ARM GPCI Investigation of Clouds

    SciTech Connect (OSTI)

    Lewis, ER; Wiscombe, WJ; Albrecht, BA; Bland, GL; Flagg, CN; Klein, SA; Kollias, P; Mace, G; Reynolds, RM; Schwartz, SE; Siebesma, AP; Teixeira, J; Wood, R; Zhang, M

    2012-10-03

    The second Atmospheric Radiation Measurement (ARM) Mobile Facility (AMF2) will be deployed aboard the Horizon Lines cargo container ship merchant vessel (M/V) Spirit for MAGIC, the Marine ARM GPCI1 Investigation of Clouds. The Spirit will traverse the route between Los Angeles, California, and Honolulu, Hawaii, from October 2012 through September 2013 (except for a few months in the middle of this time period when the ship will be in dry dock). During this field campaign, AMF2 will observe and characterize the properties of clouds and precipitation, aerosols, and atmospheric radiation; standard meteorological and oceanographic variables; and atmospheric structure. There will also be two intensive observational periods (IOPs), one in January 2013 and one in July 2013, during which more detailed measurements of the atmospheric structure will be made.

  4. Scientific Cloud Computing Misconceptions

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Scientific Cloud Computing Misconceptions Scientific Cloud Computing Misconceptions July 1, 2011 Part of the Magellan project was to understand both the possibilities and the limitations of cloud computing in the pursuit of science. At a recent conference, Magellan investigator Shane Canon outlined some persistent misconceptions about doing science in the cloud - and what Magellan has taught us about them. » Read the ISGTW story. » Download the slides (PDF, 4.1MB

  5. Sensitivity of CAM5-Simulated Arctic Clouds and Radiation to Ice Nucleation Parameterization

    SciTech Connect (OSTI)

    Xie, Shaocheng; Liu, Xiaohong; Zhao, Chuanfeng; Zhang, Yuying

    2013-08-01

    Sensitivity of Arctic clouds and radiation in the Community Atmospheric Model version 5 to the ice nucleation process is examined by testing a new physically based ice nucleation scheme that links the variation of ice nuclei (IN) number concentration to aerosol properties. The default scheme parameterizes the IN concentration simply as a function of ice supersaturation. The new scheme leads to a significant reduction in simulated IN number concentrations at all latitudes while changes in cloud amount and cloud properties are mainly seen in high latitudes and middle latitude storm tracks. In the Arctic, there is a considerable increase in mid-level clouds and a decrease in low clouds, which result from the complex interaction among the cloud macrophysics, microphysics, and the large-scale environment. The smaller IN concentrations result in an increase in liquid water path and a decrease in ice water path due to the slow-down of the Bergeron-Findeisen process in mixed-phase clouds. Overall, there is an increase in the optical depth of Arctic clouds, which leads to a stronger cloud radiative forcing (net cooling) at the top of the atmosphere. The comparison with satellite data shows that the new scheme slightly improves low cloud simulations over most of the Arctic, but produces too many mid-level clouds. Considerable improvements are seen in the simulated low clouds and their properties when compared to Arctic ground-based measurements. Issues with the observations and the model-observation comparison in the Arctic region are discussed.

  6. ARM: 10-minute Raman Lidar: aerosol extinction profiles and aerosol optical thickness, from first Ferrare algorithm

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Chitra Sivaraman; Connor Flynn

    1998-03-01

    10-minute Raman Lidar: aerosol extinction profiles and aerosol optical thickness, from first Ferrare algorithm

  7. ARM: 1-minute Raman Lidar: aerosol extinction profiles and aerosol optical thickness, from first Ferrare algorithm

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Chitra Sivaraman; Connor Flynn

    2004-10-01

    1-minute Raman Lidar: aerosol extinction profiles and aerosol optical thickness, from first Ferrare algorithm

  8. ARM: 10-minute Raman Lidar: aerosol extinction profiles and aerosol optical thickness, from first Ferrare algorithm

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Chitra Sivaraman; Connor Flynn

    10-minute Raman Lidar: aerosol extinction profiles and aerosol optical thickness, from first Ferrare algorithm

  9. ARM: 1-minute Raman Lidar: aerosol extinction profiles and aerosol optical thickness, from first Ferrare algorithm

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Chitra Sivaraman; Connor Flynn

    1-minute Raman Lidar: aerosol extinction profiles and aerosol optical thickness, from first Ferrare algorithm

  10. Cloud Properties Derived from Visible and Near-infrared Reflectance in the

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Presence of Aerosols Cloud Properties Derived from Visible and Near-infrared Reflectance in the Presence of Aerosols Hofmann, Odele University of Colorado at Boulder Pilewskie, Peter University of Colorado Gore, Warren NASA Ames Research Center Russell, Phil NASA Ames Research Center Livingston, John SRI International Redemann, Jens BAERI/NASA Ames Research Center Bergstrom, Robert Bay Area Environmental Research Institute Platnick, Steven NASA-GSFC Daniel, John NOAA Aeronomy Laboratory

  11. ARM - Field Campaign - Aerosol Life Cycle: UV-APS and Nano-SMPS

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    govCampaignsAerosol Life Cycle: UV-APS and Nano-SMPS ARM Data Discovery Browse Data Related Campaigns Aerosol Life Cycle IOP at BNL 2011.06.01, Sedlacek, OSC Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Aerosol Life Cycle: UV-APS and Nano-SMPS 2011.06.10 - 2011.06.25 Lead Scientist : Gannet Hallar For data sets, see below. Abstract Current estimates indicate that new particle formation globally account for a majority of Cloud

  12. ARM - Field Campaign - MASRAD: Cloud Condensate Nuclei Chemistry

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Measurements Cloud Condensate Nuclei Chemistry Measurements Campaign Links AMF Point Reyes Website ARM Data Discovery Browse Data Related Campaigns MArine Stratus Radiation Aerosol and Drizzle (MASRAD) IOP 2005.03.14, Miller, AMF Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : MASRAD: Cloud Condensate Nuclei Chemistry Measurements 2005.07.01 - 2005.07.30 Lead Scientist : Carl Berkowitz For data sets, see below. Abstract Principal

  13. Aerosol indirect effects ? general circulation model intercomparison and evaluation with satellite data

    SciTech Connect (OSTI)

    Quaas, Johannes; Ming, Yi; Menon, Surabi; Takemura, Toshihiko; Wang, Minghuai; Penner, Joyce E.; Gettelman, Andrew; Lohmann, Ulrike; Bellouin, Nicolas; Boucher, Olivier; Sayer, Andrew M.; Thomas, Gareth E.; McComiskey, Allison; Feingold, Graham; Hoose, Corinna; Kristansson, Jon Egill; Liu, Xiaohong; Balkanski, Yves; Donner, Leo J.; Ginoux, Paul A.; Stier, Philip; Grandey, Benjamin; Feichter, Johann; Sednev, Igor; Bauer, Susanne E.; Koch, Dorothy; Grainger, Roy G.; Kirkevag, Alf; Iversen, Trond; Seland, Oyvind; Easter, Richard; Ghan, Steven J.; Rasch, Philip J.; Morrison, Hugh; Lamarque, Jean-Francois; Iacono, Michael J.; Kinne, Stefan; Schulz, Michael

    2010-03-12

    Aerosol indirect effects continue to constitute one of the most important uncertainties for anthropogenic climate perturbations. Within the international AEROCOM initiative, the representation of aerosol-cloud-radiation interactions in ten different general circulation models (GCMs) is evaluated using three satellite datasets. The focus is on stratiform liquid water clouds since most GCMs do not include ice nucleation effects, and none of the model explicitly parameterises aerosol effects on convective clouds. We compute statistical relationships between aerosol optical depth ({tau}{sub a}) and various cloud and radiation quantities in a manner that is consistent between the models and the satellite data. It is found that the model-simulated influence of aerosols on cloud droplet number concentration (N{sub d}) compares relatively well to the satellite data at least over the ocean. The relationship between {tau}{sub a} and liquid water path is simulated much too strongly by the models. This suggests that the implementation of the second aerosol indirect effect mainly in terms of an autoconversion parameterisation has to be revisited in the GCMs. A positive relationship between total cloud fraction (f{sub cld}) and {tau}{sub a} as found in the satellite data is simulated by the majority of the models, albeit less strongly than that in the satellite data in most of them. In a discussion of the hypotheses proposed in the literature to explain the satellite-derived strong f{sub cld} - {tau}{sub a} relationship, our results indicate that none can be identified as a unique explanation. Relationships similar to the ones found in satellite data between {tau}{sub a} and cloud top temperature or outgoing long-wave radiation (OLR) are simulated by only a few GCMs. The GCMs that simulate a negative OLR - {tau}{sub a} relationship show a strong positive correlation between {tau}{sub a} and f{sub cld} The short-wave total aerosol radiative forcing as simulated by the GCMs is

  14. Climate Impacts of Atmospheric Sulfate and Black Carbon Aerosols

    SciTech Connect (OSTI)

    Qian, Yun; Song, Qingyuan; Menon, Surabi; Yu, Shaocai; Liu, Shaw C.; Shi, Guangyu; Leung, Lai R.; Luo, Yunfeng

    2008-09-19

    Although the global average surface temperature has increased by about 0.6°C during the last century (IPCC, 2001), some regions such as East Asia, Eastern North America, and Western Europe have cooled rather than warmed during the past decades (Jones, 1988; Qian and Giorgi, 2000). Coherent changes at the regional scale may reflect responses to different climate forcings that need to be understood in order to predict the future net climate response at the global and regional scales under different emission scenarios. Atmospheric aerosols play an important role in global climate change (IPCC 2001). They perturb the earth’s radiative budget directly by scattering and absorbing solar and long wave radiation, and indirectly by changing cloud reflectivity, lifetime, and precipitation efficiency via their role as cloud condensation nuclei. Because aerosols have much shorter lifetime (days to weeks) compared to most greenhouse gases, they tend to concentrate near their emission sources and distribute very unevenly both in time and space. This non-uniform distribution of aerosols, in conjunction with the greenhouse effect, may lead to differential net heating in some areas and net cooling in others (Penner et al. 1994). Sulfate aerosols come mainly from the oxidation of sulfur dioxide (SO2) emitted from fossil fuel burning. Black carbon aerosols are directly emitted during incomplete combustion of biomass, coal, and diesel derived sources. Due to the different optical properties, sulfate and black carbon affect climate in different ways. Because of the massive emissions of sulfur and black carbon that accompany the rapid economic expansions in East Asia, understanding the effects of aerosols on climate is particularly important scientifically and politically in order to develop adaptation and mitigation strategies.

  15. Development of an aerosol microphysical module: Aerosol Two-dimensional bin module for foRmation and Aging Simulation (ATRAS)

    SciTech Connect (OSTI)

    Matsui, H.; Koike, Makoto; Kondo, Yutaka; Fast, Jerome D.; Takigawa, M.

    2014-09-30

    Number concentrations, size distributions, and mixing states of aerosols are essential parameters for accurate estimation of aerosol direct and indirect effects. In this study, we developed an aerosol module, designated Aerosol Two-dimensional bin module for foRmation and Aging Simulation (ATRAS), that can represent these parameters explicitly by considering new particle formation (NPF), black carbon (BC) aging, and secondary organic aerosol (SOA) processes. A two-dimensional bin representation is used for particles with dry diameters from 40 nm to 10 m to resolve both aerosol size (12 bins) and BC mixing state (10 bins) for a total of 120 bins. The particles with diameters from 1 to 40 nm are resolved using an additional 8 size bins to calculate NPF. The ATRAS module was implemented in the WRF-chem model and applied to examine the sensitivity of simulated mass, number, size distributions, and optical and radiative parameters of aerosols to NPF, BC aging and SOA processes over East Asia during the spring of 2009. BC absorption enhancement by coating materials was about 50% over East Asia during the spring, and the contribution of SOA processes to the absorption enhancement was estimated to be 10 20% over northern East Asia and 20 35% over southern East Asia. A clear north-south contrast was also found between the impacts of NPF and SOA processes on cloud condensation nuclei (CCN) concentrations: NPF increased CCN concentrations at higher supersaturations (smaller particles) over northern East Asia, whereas SOA increased CCN concentrations at lower supersaturations (larger particles) over southern East Asia. Application of ATRAS to East Asia also showed that the impact of each process on each optical and radiative parameter depended strongly on the process and the parameter in question. The module can be used in the future as a benchmark model to evaluate the accuracy of simpler aerosol models and examine interactions between NPF, BC aging, and SOA processes

  16. Monodisperse aerosol generator

    DOE Patents [OSTI]

    Ortiz, Lawrence W.; Soderholm, Sidney C.

    1990-01-01

    An aerosol generator is described which is capable of producing a monodisperse aerosol within narrow limits utilizing an aqueous solution capable of providing a high population of seed nuclei and an organic solution having a low vapor pressure. The two solutions are cold nebulized, mixed, vaporized, and cooled. During cooling, particles of the organic vapor condense onto the excess seed nuclei, and grow to a uniform particle size.

  17. Ganges Valley Aerosol Experiment: Science and Operations Plan

    SciTech Connect (OSTI)

    Kotamarthi, VR

    2010-06-21

    The Ganges Valley region is one of the largest and most rapidly developing sections of the Indian subcontinent. The Ganges River, which provides the region with water needed for sustaining life, is fed primarily by snow and rainfall associated with Indian summer monsoons. Impacts of changes in precipitation patterns, temperature, and the flow of the snow-fed rivers can be immense. Recent satellite-based measurements have indicated that the upper Ganges Valley has some of the highest persistently observed aerosol optical depth values. The aerosol layer covers a vast region, extending across the Indo-Gangetic Plain to the Bay of Bengal during the winter and early spring of each year. The persistent winter fog in the region is already a cause of much concern, and several studies have been proposed to understand the economic, scientific, and societal dimensions of this problem. During the INDian Ocean EXperiment (INDOEX) field studies, aerosols from this region were shown to affect cloud formation and monsoon activity over the Indian Ocean. This is one of the few regions showing a trend toward increasing surface dimming and enhanced mid-tropospheric warming. Increasing air pollution over this region could modify the radiative balance through direct, indirect, and semi-indirect effects associated with aerosols. The consequences of aerosols and associated pollution for surface insolation over the Ganges Valley and monsoons, in particular, are not well understood. The proposed field study is designed for use of (1) the ARM Mobile Facility (AMF) to measure relevant radiative, cloud, convection, and aerosol optical characteristics over mainland India during an extended period of 912 months and (2) the G-1 aircraft and surface sites to measure relevant aerosol chemical, physical, and optical characteristics in the Ganges Valley during a period of 612 weeks. The aerosols in this region have complex sources, including burning of coal, biomass, and biofuels; automobile

  18. Development of RAMS-CMAQ to Simulate Aerosol Optical Depth and Aerosol Direct Radiative Forcing and Its Application to East Asia

    SciTech Connect (OSTI)

    Han, Xiao; Zhang, Meigen; Liu, Xiaohong; Ghan, Steven J.; Xin, Jin-Yuan; Wang, Li-Li

    2009-11-16

    The air quality modeling system RAMS (Regional Atmospheric Modeling System)-CMAQ (Models-3 Community Multi-scale Air Quality) is developed to simulate the aerosol optical depth (AOD) and aerosol direct forcing (DF). The aerosol-specific extinction, single scattering albedo, and asymmetry factor are parameterized based on Mie theory taking into account the aerosol size distribution, composition, refractive index, and water uptake of solution particles. A two-stream solar radiative model considers all gaseous molecular absorption, Rayleigh scattering, and aerosols and clouds. RAMSCMAQ is applied to simulate all major aerosol concentrations (e.g., sulfate, nitrate, ammonium, organic carbon, black carbon, fine soil, and sea salt) and AOD and DF over East Asia in 2005. To evaluate its performance, the simulated AOD values were compared with ground-based in situ measurements. The comparison shows that RAMSCMAQ performed well in most of the model domain and generally captured the observed variations. High AOD values (0.2−1.0) mainly appear in the Sichuan Basin as well as in central and southeastern China. The geographic distribution of DF generally follows the AOD distribution patterns, and the DF at the top-of-the-atmosphere is less than −25 and −20 W m−2 in clear-sky and all-sky over the Sichuan Basin. Both AOD and DF exhibit seasonal variations with lower values in July and higher ones in January. The DF could obviously be impacted by high cloud fractions.

  19. Clouds and climate: Unraveling a key piece of global warming

    SciTech Connect (OSTI)

    Seinfeld, J.H.

    2000-02-01

    Federal policy decisions relating to mitigation of greenhouse gas and other emissions have the potential to exert an enormous impact on industries in which chemical engineers play a prominent role. Many in these industries keep close watch on the development of scientific understanding associated with predictions of global climate change. The authors review one of the most critical, and most uncertain, pieces of the climate puzzle, the role of aerosols and clouds in the global energy balance.

  20. Cloud Retrievals from Landsat-7 During ARESE II

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Cloud Retrievals from Landsat-7 During ARESE II L. Oreopoulos, G. Wen, and A. Marshak Joint Center for Earth Systems Technology University of Maryland Baltimore County Baltimore, Maryland R. F. Cahalan National Aeronautics and Space Administration Goddard Space Flight Center Climate and Radiation Branch Greenbelt, Maryland D. Kratz National Aeronautics and Space Administration Langley Research Center Radiation and Aerosols Branch Hampton, Virginia Background on Landsat-7 While for most Landsat

  1. Automated retrieval of cloud and aerosol properties from the...

    Office of Scientific and Technical Information (OSTI)

    Authors: Thorsen, Tyler J. ; Fu, Qiang ; Newsom, Rob K. ; Turner, David D. ; Comstock, Jennifer M. Publication Date: 2015-11-01 OSTI Identifier: 1243274 Report Number(s): ...

  2. Biogenic Aerosols-Effects on Clouds and Climate (BAECC)

    Office of Scientific and Technical Information (OSTI)

    ... Geophysical Research Letters 24(10): 1219-1222, doi: 10.102997GL00920. Makkonen, R, A Asmi, V-M Kerminen, M Boy A Arneth, P Hari, and M Kulmala. 2012. "Air pollution control and ...

  3. ARM - Field Campaign - ARM Cloud Aerosol Precipitation Experiment...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    a distinctly different INP population in comparison to long range transported desert or urban and regional land-sourced INP, and that the layering of marine within other...

  4. Observed correlations between aerosol and cloud properties in...

    Office of Scientific and Technical Information (OSTI)

    these covariations: high-pollution cases are shown to originate as a highly polluted boundary layer air mass approaching the observatory from a northwesterly direction. ...

  5. ARM - Field Campaign - Aerosol and Cloud Experiments in the Eastern...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Duli Chand J.-Y. Christine Chiu Xiquan Dong Jerome Fast Andrew Gettelman Steven Ghan Scott Giangrande Mary Gilles Anne Jefferson Michael Jensen Pavlos Kollias Chongai Kuang...

  6. Understanding the Effect of Aerosol Properties on Cloud Droplet...

    Office of Scientific and Technical Information (OSTI)

    Authors: Cziczo, Daniel 1 + Show Author Affiliations Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States) Publication Date: 2016-05-01 OSTI Identifier: 1253924 ...

  7. Cloud Condensation Nuclei Activity of Aerosols during GoAmazon...

    Office of Scientific and Technical Information (OSTI)

    Brookhaven National Lab. (BNL), Upton, NY (United States) Harvard Univ., Cambridge, MA (United States) Publication Date: 2016-03-01 OSTI Identifier: 1248889 Report ...

  8. Biogenic Aerosols-Effects on Clouds and Climate: Snowfall Experiment...

    Office of Scientific and Technical Information (OSTI)

    a double-fence intercomparison reference wind protection for the weighing precipitation ... their measurement errors as a function of wind speed, thus aiming at providing a ...

  9. Clouds, Aerosol, and Precipitation in the Marine Boundary Layer...

    Office of Scientific and Technical Information (OSTI)

    These couplings have been documented as a result of past field programs and model studies. However, extensive research is still required to achieve a quantitative understanding ...

  10. The Radiative Role of Free Tropospheric Aerosols and Marine Clouds...

    Office of Scientific and Technical Information (OSTI)

    The project was 'exploratory' in nature, with the plan to demonstrate the feasibility of ... to two papers published in the Nature Publishing group (Nature Communications ...

  11. Corrigendum to Aerosol impacts on California winter clouds and...

    Office of Scientific and Technical Information (OSTI)

    CalWater 2011: local pollution versus long-range transported dust published in Atmos. ... CalWater 2011: local pollution versus long-range transported dust published in Atmos. ...

  12. Aerosol Impacts on California Winter Clouds and Precipitation...

    Office of Scientific and Technical Information (OSTI)

    CalWater 2011: Local Pollution versus Long-Range Transported Dust Citation Details ... CalWater 2011: Local Pollution versus Long-Range Transported Dust Mineral dust ...

  13. ARM - Field Campaign - ARM Cloud Aerosol Precipitation Experiment...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    remote sensing for resolving and studying the above processes? (i.e., Satellite CalVal) We have recently added a fourth study focused on the transport and evolution of...

  14. Clouds, Aerosol, and Precipitation in the Marine Boundary Layer...

    Office of Scientific and Technical Information (OSTI)

    Close Cite: Bibtex Format Close 0 pages in this document matching the terms "" Search For Terms: Enter terms in the toolbar above to search the full text of this document for ...

  15. ARM Cloud Aerosol Precipitation Experiment (ACAPEX) Science Plan...

    Office of Scientific and Technical Information (OSTI)

    Because of the large lower-tropospheric water vapor content, strong atmospheric winds and neutral moist static stability, some ARs can produce heavy precipitation by orographic ...

  16. Clouds, Aerosols, and Precipitation in the Marine Boundary Layer...

    Office of Scientific and Technical Information (OSTI)

    ; Stemmler, Jayson ; de Szoeke, Simone ; Yuter, Sandra ; Miller, Matthew ; Mechem, David ; Tselioudis, George ; Chiu, J. Christine ; Mann, Julian A. L. ; O'Connor, Ewan J. ; ...

  17. Clouds, aerosol, and precipitation in the Marine Boundary Layer...

    Office of Scientific and Technical Information (OSTI)

    Jayson 1 ; deSzoeke, S. 5 ; Yuter, Sandra 6 ; Miller, Matthew 6 ; Mechem, David 7 ; Tselioudis, George 3 ; Chiu, Christine 8 ; Mann, Julia 8 ; O Connor, ...

  18. Holistic Interactions of Shallow Clouds, Aerosols, and Land-Ecosystems...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    J Shilling J Fan M Shrivastava Z Feng J Smith S Hagos J Thornton M Huang D Tuner A ... Pacific Northwest National Laboratory J Smith, University of California, Irvine J ...

  19. General circulation model calculations of the direct radiative forcing by anthropogenic sulfate and fossil-fuel soot aerosol

    SciTech Connect (OSTI)

    Haywood, J.M.; Roberts, D.L.; Slingo, A.

    1997-07-01

    A new radiation code within a general circulation model is used to assess the direct solar and thermal radiative forcing by sulfate aerosol of anthropogenic origin and soot aerosol from fossil-fuel burning. The radiative effects of different aerosol profiles, relative humidity parameterizations, chemical compositions, and internal and external mixtures of the two aerosol types are investigated. The contribution to the radiative forcing from cloudy sky regions is found to be negligible for sulfate aerosol; this is in contrast to recent studies where the cloudy sky contribution was estimated using a method in which the spatial correlation between cloud amount and sulfate burden was ignored. However, the radiative forcing due to fossil-fuel soot aerosol is enhanced in cloudy regions if soot aerosol exists within or above the cloud. The global solar radiative forcing due to sulfate aerosol is estimated to be -0.38 W m{sup -2} and the global thermal radiative forcing is estimated to be +0.01 W m{sup -2}. The hemispheric mean radiative forcings vary by only about 10% for reasonable assumptions about the chemical form of the sulfate aerosol and the relative humidity dependence; the uncertainties in the aerosol loading are far more significant. If a soot/sulfate mass ratio of 0.075 is assumed, then the global solar radiative forcing weakens to -0.18 W m{sup -2} for an external mixture and weakens further for an internal mixture. Additionally, the spatial distribution of the radiative forcing shows strong negative/positive forcing contrasts that may influence the dynamical response of the atmosphere. Although these results are extremely sensitive to the adopted soot/sulfate ratio and the assumed vertical profile, they indicate that fossil-fuel soot aerosol may exert a nonnegligible radiative forcing and emphasize the need to consider each anthropogenic aerosol species. 58 refs., 8 figs., 1 tab.

  20. Aqueous Processing of Atmospheric Organic Particles in Cloud Water Collected via Aircraft Sampling

    SciTech Connect (OSTI)

    Boone, Eric J.; Laskin, Alexander; Laskin, Julia; Wirth, Christopher; Shepson, Paul B.; Stirm, Brian H.; Pratt, Kerri A.

    2015-07-21

    Cloud water and below-cloud atmospheric particle samples were collected onboard a research aircraft during the Southern Oxidant and Aerosol Study (SOAS) over a forested region of Alabama in June 2013. The organic molecular composition of the samples was studied to gain insights into the aqueous-phase processing of organic compounds within cloud droplets. High resolution mass spectrometry with nanospray desorption electrospray ionization and direct infusion electrospray ionization were utilized to compare the organic composition of the particle and cloud water samples, respectively. Isoprene and monoterpene-derived organosulfates and oligomers were identified in both the particles and cloud water, showing the significant influence of biogenic volatile organic compound oxidation above the forested region. While the average O:C ratios of the organic compounds were similar between the atmospheric particle and cloud water samples, the chemical composition of these samples was quite different. Specifically, hydrolysis of organosulfates and formation of nitrogen-containing compounds were observed for the cloud water when compared to the atmospheric particle samples, demonstrating that cloud processing changes the composition of organic aerosol.

  1. In situ measurements of heterogeneous reactions on ambient aerosol particles: Impacts on atmospheric chemistry and climate

    SciTech Connect (OSTI)

    Bertram, Timothy

    2015-02-11

    Aerosol particles play a critical role in the Earth’s energy budget through the absorption and scattering of radiation, and/or through their ability to form clouds and alter cloud lifetime. Heterogeneous and multi-phase reactions alter the climate-relevant properties of aerosol particles and catalyze reaction pathways that are energetically unfavorable in the gas phase. The chemical composition of aerosol particles dictates the kinetics of heterogeneous and multi-phase reactions. At present, the vast majority of the molecular level information on these processes has been determined in laboratory investigations on model aerosol systems. The work described here provides a comprehensive investigation into the reactivity of complex, ambient aerosol particles is proposed to determine: 1) how representative laboratory investigations of heterogeneous and multi-phase processes conducted on model, simple systems are of the real atmosphere, and 2) the impact of heterogeneous and multi-phase processes on ambient particle optical properties and their ability to nucleate clouds. This work has focused on the uptake kinetics for ammonia (NH3) and dinitrogen pentoxide (N2O5). The results of these investigations will be used to directly improve the representation of heterogeneous and multi-phase processes in global climate models, by identifying the key mechanistic drivers that control the variability in the observed kinetics.

  2. Effects of Aerosols on Autumn Precipitation over Mid-Eastern China

    SciTech Connect (OSTI)

    Chen, Siyu; Huang, J.; Qian, Yun; Ge, Jinming; Su, Jing

    2014-09-20

    Long-term observational data indicated a decreasing trend for the amount of autumn precipitation (i.e. 54.3 mm per decade) over Mid-Eastern China, especially after 1980s (~ 5.6% per decade). To examine the cause of the decreasing trend, the mechanisms associated with the change of autumn precipitation were investigated from the perspective of water vapor transportation, atmospheric stability and cloud microphysics. Results show that the decrease of convective available potential energy (i.e. 12.81 J kg-1/ decade) and change of cloud microphysics, which were closely related to the increase of aerosol loading during the past twenty years, were the two primary factors responsible for the decrease of autumn precipitation. Ours results showed that increased aerosol could enhance the atmospheric stability thus weaken the convection. Meanwhile, more aerosols also led to a significant decline of raindrop concentration and to a delay of raindrop formation because of smaller size of cloud droplets. Thus, increased aerosols produced by air pollution could be one of the major reasons for the decrease of autumn precipitation. Furthermore, we found that the aerosol effects on precipitation in autumn was more significant than in other seasons, partly due to the relatively more stable synoptic system in autumn. The impact of large-scale circulation dominated in autumn and the dynamic influence on precipitation was more important than the thermodynamic activity.

  3. Project Overview: Cumulus Humilis Aerosol Processing Study (CHAPS): Proposed Summer 2007 ASP Field Campaign

    SciTech Connect (OSTI)

    Berkowitz, Carl M.; Berg, Larry K.; Ogren, J. A.; Hostetler, Chris A.; Ferrare, Richard

    2006-05-18

    This white paper presents the scientific motivation and preliminary logistical plans for a proposed ASP field campaign to be carried out in the summer of 2007. The primary objective of this campaign is to use the DOE Gulfstream-1 aircraft to make measurements characterizing the chemical, physical and optical properties of aerosols below, within and above large fields of fair weather cumulus and to use the NASA Langley Research Centers High Spectral Resolution Lidar (HSRL) to make independent measurements of aerosol backscatter and extinction profiles in the vicinity of these fields. Separate from the science questions to be addressed by these observations will be information to add in the development of a parameterized cumulus scheme capable of including multiple cloud fields within a regional or global scale model. We will also be able to compare and contrast the cloud and aerosol properties within and outside the Oklahoma City plume to study aerosol processes within individual clouds. Preliminary discussions with the Cloud and Land Surface Interaction Campaign (CLASIC) science team have identified overlap between the science questions posed for the CLASIC Intensive Operation Period (IOP) and the proposed ASP campaign, suggesting collaboration would benefit both teams.

  4. ARM - Measurement - Cloud fraction

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Flux Analysis SWFLUXANAL : Shortwave Flux Analysis TSI : Total Sky Imager UAV-EGRETT : UAV-Egrett WSI : Whole Sky Imager WSICLOUD : Whole Sky Imager Cloud Products ...

  5. Finance Idol Word Cloud

    Broader source: Energy.gov [DOE]

    This word cloud represents the topics discussed during the Big and Small Ideas: How to Lower Solar Financing Costs breakout session at the SunShot Grand Challenge.

  6. ARM - Measurement - Cloud phase

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    that involves property descriptors such as stratus, cumulus, and cirrus. Categories Cloud Properties Instruments The above measurement is considered scientifically relevant for the...

  7. ARM - Measurement - Aerosol effective radius

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    would love to hear from you Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Aerosol effective radius Aerosol effective radius is the ratio of the third and...

  8. Laboratory Studies of Processing of Carbonaceous Aerosols by Atmospheric Oxidants/Hygroscopicity and CCN Activity of Secondary & Processed Primary Organic Aerosols

    SciTech Connect (OSTI)

    Ziemann, P.J.; Arey, J.; Atkinson, R.; Kreidenweis, S.M.; Petters, M.D.

    2012-06-13

    The atmosphere is composed of a complex mixture of gases and suspended microscopic aerosol particles. The ability of these particles to take up water (hygroscopicity) and to act as nuclei for cloud droplet formation significantly impacts aerosol light scattering and absorption, and cloud formation, thereby influencing air quality, visibility, and climate in important ways. A substantial, yet poorly characterized component of the atmospheric aerosol is organic matter. Its major sources are direct emissions from combustion processes, which are referred to as primary organic aerosol (POA), or in situ processes in which volatile organic compounds (VOCs) are oxidized in the atmosphere to low volatility reaction products that subsequent condense to form particles that are referred to as secondary organic aerosol (SOA). POA and VOCs are emitted to the atmosphere from both anthropogenic and natural (biogenic) sources. The overall goal of this experimental research project was to conduct laboratory studies under simulated atmospheric conditions to investigate the effects of the chemical composition of organic aerosol particles on their hygroscopicity and cloud condensation nucleation (CCN) activity, in order to develop quantitative relationships that could be used to more accurately incorporate aerosol-cloud interactions into regional and global atmospheric models. More specifically, the project aimed to determine the products, mechanisms, and rates of chemical reactions involved in the processing of organic aerosol particles by atmospheric oxidants and to investigate the relationships between the chemical composition of organic particles (as represented by molecule sizes and the specific functional groups that are present) and the hygroscopicity and CCN activity of oxidized POA and SOA formed from the oxidation of the major classes of anthropogenic and biogenic VOCs that are emitted to the atmosphere, as well as model hydrocarbons. The general approach for this project was

  9. Boundary Layer Cloud Turbulence Characteristics

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Boundary Layer Cloud Turbulence Characteristics Virendra Ghate Bruce Albrecht Parameter Observational Readiness (/10) Modeling Need (/10) Cloud Boundaries 9 9 Cloud Fraction Variance Skewness Up/Downdraft coverage Dominant Freq. signal Dissipation rate ??? Observation-Modeling Interface

  10. Highly stable aerosol generator

    DOE Patents [OSTI]

    DeFord, H.S.; Clark, M.L.

    1981-11-03

    An improved compressed air nebulizer has been developed such that a uniform aerosol particle size and concentration may be produced over long time periods. This result is achieved by applying a vacuum pressure to the makeup assembly and by use of a vent tube between the atmosphere and the makeup solution. By applying appropriate vacuum pressures to the makeup solution container and by proper positioning of the vent tube, a constant level of aspirating solution may be maintained within the aspirating assembly with aspirating solution continuously replaced from the makeup solution supply. This device may also be adapted to have a plurality of aerosol generators and only one central makeup assembly. 2 figs.

  11. Highly stable aerosol generator

    DOE Patents [OSTI]

    DeFord, Henry S.; Clark, Mark L.

    1981-01-01

    An improved compressed air nebulizer has been developed such that a uniform aerosol particle size and concentration may be produced over long time periods. This result is achieved by applying a vacuum pressure to the makeup assembly and by use of a vent tube between the atmosphere and the makeup solution. By applying appropriate vacuum pressures to the makeup solution container and by proper positioning of the vent tube, a constant level of aspirating solution may be maintained within the aspirating assembly with aspirating solution continuously replaced from the makeup solution supply. This device may also be adapted to have a plurality of aerosol generators and only one central makeup assembly.

  12. Observations of regional and local variability in the optical properties of maritime clouds

    SciTech Connect (OSTI)

    White, A.B.

    1996-04-01

    White and Fairall (1995) calculated the optical properties of the marine boundary layer (MBL) clouds observed during the Atlantic Stratocumulus Transition Experiment (ASTEX) and compared their results with the results obtained by Fairall et al. for the MBL clouds observed during the First International Satellite Climatology Program (ISSCP) Regional Experiment (FIRE). They found a factor of two difference in the optical depth versus liquid water relationship that applies to the clouds observed in each case. In the present study, we present evidence to support this difference. We also investigate the local variability exhibited in the ASTEX optical properties using measurements of the boundary layer aerosol concentration.

  13. Validation of a radar doppler spectra simulator using measurements from the ARM cloud radars

    SciTech Connect (OSTI)

    Remillard, J.; Luke, E.; Kollias, P.

    2010-03-15

    The use of forward models as an alternative approach to compare models with observations contains advantages and challenges. Radar Doppler spectra simulators are not new; their application in high- resolution models with bin microphysics schemes could help to compare model output with the Doppler spectra recorded from the vertically pointing cloud radars at the ARM Climate Research Facility sites. The input parameters to a Doppler spectra simulator are both microphysical (e.g., particle size, shape, phase, and number concentration) and dynamical (e.g., resolved wind components and sub-grid turbulent kinetic energy). Libraries for spherical and non-spherical particles are then used to compute the backscattering cross-section and fall velocities, while the turbulence is parameterized as a Gaussian function with a prescribed width. The Signal-to-Noise Ratio (SNR) is used to determine the amount of noise added throughout the spectrum, and the spectral smoothing due to spectral averages is included to reproduce the averaging realized by cloud radars on successive returns. Thus, realistic Doppler spectra are obtained, and several parameters that relate to the morphological characteristics of the synthetically generated spectra are computed. Here, the results are compared to the new ARM microARSCL data products in an attempt to validate the simulator. Drizzling data obtained at the SGP site by the MMCR and the AMF site at Azores using the WACR are used to ensure the liquid part and the turbulence representation part of the simulator are properly accounted in the forward model.

  14. Aircraft-measured indirect cloud effects from biomass burning smoke in the Arctic and subarctic

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Zamora, L. M.; Kahn, R. A.; Cubison, M. J.; Diskin, G. S.; Jimenez, J. L.; Kondo, Y.; McFarquhar, G. M.; Nenes, A.; Thornhill, K. L.; Wisthaler, A.; et al

    2016-01-21

    The incidence of wildfires in the Arctic and subarctic is increasing; in boreal North America, for example, the burned area is expected to increase by 200–300% over the next 50–100 years, which previous studies suggest could have a large effect on cloud microphysics, lifetime, albedo, and precipitation. However, the interactions between smoke particles and clouds remain poorly quantified due to confounding meteorological influences and remote sensing limitations. Here, we use data from several aircraft campaigns in the Arctic and subarctic to explore cloud microphysics in liquid-phase clouds influenced by biomass burning. Median cloud droplet radii in smoky clouds were ~40–60% smallermore » than in background clouds. Based on the relationship between cloud droplet number (Nliq) and various biomass burning tracers (BBt) across the multi-campaign data set, we calculated the magnitude of subarctic and Arctic smoke aerosol–cloud interactions (ACIs, where ACI = (1/3) × dln(Nliq)/dln(BBt)) to be ~0.16 out of a maximum possible value of 0.33 that would be obtained if all aerosols were to nucleate cloud droplets. Interestingly, in a separate subarctic case study with low liquid water content (~0.02gm–3) and very high aerosol concentrations (2000–3000 cm–3) in the most polluted clouds, the estimated ACI value was only 0.05. In this case, competition for water vapor by the high concentration of cloud condensation nuclei (CCN) strongly limited the formation of droplets and reduced the cloud albedo effect, which highlights the importance of cloud feedbacks across scales. Using our calculated ACI values, we estimate that the smoke-driven cloud albedo effect may decrease local summertime short-wave radiative flux by between 2 and 4 Wm–2 or more under some low and homogeneous cloud cover conditions in the subarctic, although the changes should be smaller in high surface albedo regions of the Arctic. Furthermore, we lastly explore evidence suggesting that

  15. Cloud computing security.

    SciTech Connect (OSTI)

    Shin, Dongwan; Claycomb, William R.; Urias, Vincent E.

    2010-10-01

    Cloud computing is a paradigm rapidly being embraced by government and industry as a solution for cost-savings, scalability, and collaboration. While a multitude of applications and services are available commercially for cloud-based solutions, research in this area has yet to fully embrace the full spectrum of potential challenges facing cloud computing. This tutorial aims to provide researchers with a fundamental understanding of cloud computing, with the goals of identifying a broad range of potential research topics, and inspiring a new surge in research to address current issues. We will also discuss real implementations of research-oriented cloud computing systems for both academia and government, including configuration options, hardware issues, challenges, and solutions.

  16. RACORO long-term, systematic aircraft observations of boundary layer clouds

    SciTech Connect (OSTI)

    Vogelmann, A.M.; McFarquhar, G.; Ogren, J.; Turner, D. D.; Comstock, J. M.; Feingold, G.; Long, C. N.; Jonsson, H. H.; Bucholtz, A.; Collins, D. R.; Diskin, G.; Gerber, H.; Lawson, R. P.; Woods, R. K.; Hubbe, J.; Tomlinson, J.; Schmid, B.

    2010-06-27

    Our knowledge of boundary layer cloud processes is insufficient to resolve pressing scientific problems. Boundary layer clouds often have liquid-water paths (LWPs) less than 100 gm{sup 2}, which are defined here as being 'thin' Clouds with Low Optical Water Depths (CLOWD). This type of cloud is common globally, and the Earth's radiative energy balance is particularly sensitive to small changes in their optical properties. However, it is difficult to retrieve accurately their cloud properties via remote sensing because they are tenuous and often occur in partly cloudy skies. This interferes with our ability to obtain the routine, long-term statistics needed to improve their representation in climate models. To address this problem, in-situ data are needed to investigate cloud processes and to evaluate and refine existing retrieval algorithms. Coordinated by the ARM Aerial Facility (AAF), the Routine AAF CLOWD Optical Radiative Observations (RACORO) field campaign conducted long-term, systematic flights in boundary layer, liquid-water clouds over the ARM Southern Great Plains (SGP) site between 22 January and 30 June 2009. This was the first time that a long-term aircraft campaign was undertaken for systematic in-situ sampling of cloud properties. Using the CIRPAS Twin Otter aircraft equipped with a comprehensive set of instruments to measure solar and thermal radiation, cloud microphysics, aerosol properties and atmospheric state, the RACORO team logged an unprecedented 59 flights and 259 research hours above the SGP site. Data gathered during the RACORO campaign will provide researchers with a statistically relevant data set of boundary-layer cloud and aerosol properties for future study. These data can be used to validate retrieval algorithms and support process studies and model simulations of boundary layer clouds and, in particular, CLOWD-type clouds. In addition to cloud observations, complementary clear-sky flight patterns were conducted to map the surface

  17. Temperature, Water Vapor, and Clouds"

    Office of Scientific and Technical Information (OSTI)

    Radiometric Studies of Temperature, Water Vapor, and Clouds" Project ID: 0011106 ... measurements of column amounts of water vapor and cloud liquid has been well ...

  18. TC_CLOUD_REGIME.cdr

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    intensity (e.g. May and Ballinger, 2007) Resulting Cloud Properties Examine rain DSD using polarimetric radar Examine ice cloud properties using MMCR and MPL Expect...

  19. ARM - Measurement - Cloud effective radius

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    the number size distribution of cloud particles, whether liquid or ice. Categories Cloud Properties Instruments The above measurement is considered scientifically relevant for the...

  20. Testing Cloud Microphysics Parameterizations in NCAR CAM5 with ISDAC and M-PACE Observations

    SciTech Connect (OSTI)

    Liu, Xiaohong; Xie, Shaocheng; Boyle, James; Klein, Stephen A.; Shi, Xiangjun; Wang, Zhien; Lin, Wuyin; Ghan, Steven J.; Earle, Michael; Liu, Peter; Zelenyuk, Alla

    2011-12-24

    Arctic clouds simulated by the NCAR Community Atmospheric Model version 5 (CAM5) are evaluated with observations from the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Indirect and Semi-Direct Aerosol Campaign (ISDAC) and Mixed-Phase Arctic Cloud Experiment (M-PACE), which were conducted at its North Slope of Alaska site in April 2008 and October 2004, respectively. Model forecasts for the Arctic Spring and Fall seasons performed under the Cloud- Associated Parameterizations Testbed (CAPT) framework generally reproduce the spatial distributions of cloud fraction for single-layer boundary layer mixed-phase stratocumulus, and multilayer or deep frontal clouds. However, for low-level clouds, the model significantly underestimates the observed cloud liquid water content in both seasons and cloud fraction in the Spring season. As a result, CAM5 significantly underestimates the surface downward longwave (LW) radiative fluxes by 20-40 W m-2. The model with a new ice nucleation parameterization moderately improves the model simulations by increasing cloud liquid water content in mixed-phase clouds through the reduction of the conversion rate from cloud liquid to ice by the Wegener-Bergeron- Findeisen (WBF) process. The CAM5 single column model testing shows that change in the homogeneous freezing temperature of rain to form snow from -5 C to -40 C has a substantial impact on the modeled liquid water content through the slowing-down of liquid and rain-related processes. In contrast, collections of cloud ice by snow and cloud liquid by rain are of minor importance for single-layer boundary layer mixed-phase clouds in the Arctic.

  1. Residence times of fine tropospheric aerosols as determined by {sup 210}Pb progeny.

    SciTech Connect (OSTI)

    Marley, N. A.; Gaffney, J. S.; Drayton, P. J.; Cunningham, M. M.; Mielcarek, C.; Ravelo, R.; Wagner, C.

    1999-10-05

    Fine tropospheric aerosols can play important roles in the radiative balance of the atmosphere. The fine aerosols can act directly to cool the atmosphere by scattering incoming solar radiation, as well as indirectly by serving as cloud condensation nuclei. Fine aerosols, particularly carbonaceous soots, can also warm the atmosphere by absorbing incoming solar radiation. In addition, aerosols smaller than 2.5 {micro}m have recently been implicated in the health effects of air pollution. Aerosol-active radioisotopes are ideal tracers for the study of atmospheric transport processes. The source terms of these radioisotopes are relatively well known, and they are removed from the atmosphere only by radioactive decay or by wet or dry deposition of the host aerosol. The progeny of the primordial radionuclide {sup 238}U are of particular importance to atmospheric studies. Uranium-238 is common throughout Earth's crust and decays to the inert gas {sup 222}Rn, which escapes into the atmosphere. Radon-222 decays by the series of alpha and beta emissions shown in Figure 1 to the long-lived {sup 210}Pb. Once formed, {sup 210}Pb becomes attached to aerosol particles with average attachment times of 40 s to 3 min.

  2. Impact of aerosol size representation on modeling aerosolâ*...

    Office of Scientific and Technical Information (OSTI)

    ... Technol., 20, 1 -30, 1994. Jacobson, M. Z., Development and application of a new air pollution mod- eling system, II, Aerosol module structure and design, Atmos. Environ., 31, ...

  3. Magellan: A Cloud Computing Testbed

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Magellan News & Announcements Archive Petascale Initiative Exascale Computing APEX Home » R & D » Archive » Magellan: A Cloud Computing Testbed Magellan: A Cloud Computing Testbed Cloud computing is gaining a foothold in the business world, but can clouds meet the specialized needs of scientists? That was one of the questions NERSC's Magellan cloud computing testbed explored between 2009 and 2011. The goal of Magellan, a project funded through the U.S. Department of Energy (DOE) Oce

  4. Diagnosis of Differences Between Stratiform Clouds Simulated by Large-Eddy Simulation and Single-Column Models

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Diagnosis of Differences Between Stratiform Clouds and Simulated by Large-Eddy Simulation and Single-Column Models S. J. Ghan and M. Ovtchinnikov Climate Physics Pacific Northwest National Laboratory Richland, Washington Introduction An adequate parameterization of cloud microphysics is essential for estimating the indirect aerosol effect in large-scale models. Such a parameterization must rely on a physically sound treatment of spatial variability that affects many microphysical processes in a

  5. Ganges Valley Aerosol Experiment

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Ganges Valley Aerosol Experiment In northeastern India, the fertile land around the Ganges River supports several hundred million people. This river, the largest in India, is fed by monsoon rains and runoff from the nearby Himalayan Mountains. Through an intergovernmental agreement with India, the U.S. Department of Energy's Atmospheric Radiation Measurement (ARM) Climate Research Facility deployed its portable laboratory, the ARM Mobile Facility (AMF), to Nainital, India, in June 2011. During

  6. The Mechanism of First Raindrops Formation in Deep Convective Clouds

    SciTech Connect (OSTI)

    Khain, Alexander; Prabha, Thara; Benmoshe, Nir; Pandithurai, G.; Ovchinnikov, Mikhail

    2013-08-22

    The formation of first raindrops in deep convective clouds is investigated. A combination of observational data analysis and 2-D and 3-D numerical bin microphysical simulations of deep convective clouds suggests that the first raindrops form at the top of undiluted or slightly diluted cores. It is shown that droplet size distributions in these regions are wider and contain more large droplets than in diluted volumes. The results of the study indicate that the initial raindrop formation is determined by the basic microphysical processes within ascending adiabatic volumes. It allows one to predict the height of the formation of first raindrops considering the processes of nucleation, diffusion growth and collisions. The results obtained in the study explain observational results reported by Freud and Rosenfeld (2012) according to which the height of first raindrop formation depends linearly on the droplet number concentration at cloud base. The results also explain why a simple adiabatic parcel model can reproduce this dependence. The present study provides a physical basis for retrieval algorithms of cloud microphysical properties and aerosol properties using satellites proposed by Rosenfeld et al. ( 2012). The study indicates that the role of mixing and entrainment in the formation of the first raindrops is not of crucial importance. It is also shown that low variability of effective and mean volume radii along horizontal traverses, as regularly observed by in situ measurements, can be simulated by high-resolution cloud models, in which mixing is parameterized by a traditional 1.5 order turbulence closure scheme.

  7. Influence of Arctic cloud thermodynamic phase on surface shortwave flux

    SciTech Connect (OSTI)

    Lubin, D.; Vogelmann, A.

    2010-03-15

    As part of the Indirect and Semi-Direct Aerosol Campaign (ISDAC) an Analytical Spectral Devices (ASD, Inc.) spectroradiometer was deployed at the Barrow NSA site during April and May of 2008, and in April-October of 2009. This instrument recorded one-minute averages of surface downwelling spectral flux in the wavelength interval 350-2200 nm, thus sampling the two major near infrared windows (1.6 and 2.2 microns) in which the flux is influenced by cloud microphysical properties including thermodynamic phase and effective particle size. Aircraft in situ measurements of cloud properties show mostly mixed-phase clouds over Barrow during the campaign, but with wide variability in relative liquid versus ice water content. At fixed total optical depth, this variability in phase composition can yield of order 5-10 Watts per square meter in surface flux variability, with greater cloud attenuation of the surface flux usually occurring under higher ice water content. Thus our data show that changes in cloud phase properties, even within the 'mixed-phase' category, can affect the surface energy balance at the same order of magnitude as greenhouse gas increases. Analysis of this spectral radiometric data provides suggestions for testing new mixed-phase parameterizations in climate models.

  8. Cantera Aerosol Dynamics Simulator

    Energy Science and Technology Software Center (OSTI)

    2004-09-01

    The Cantera Aerosol Dynamics Simulator (CADS) package is a general library for aerosol modeling to address aerosol general dynamics, including formation from gas phase reactions, surface chemistry (growth and oxidation), bulk particle chemistry, transport by Brownian diffusion, thermophoresis, and diffusiophoresis with linkage to DSMC studies, and thermal radiative transport. The library is based upon Cantera, a C++ Cal Tech code that handles gas phase species transport, reaction, and thermodynamics. The method uses a discontinuous galerkinmore » formulation for the condensation and coagulation operator that conserves particles, elements, and enthalpy up to round-off error. Both O-D and 1-D time dependent applications have been developed with the library. Multiple species in the solid phase are handled as well. The O-D application, called Tdcads (Time Dependent CADS) is distributed with the library. Tdcads can address both constant volume and constant pressure adiabatic homogeneous problems. An extensive set of sample problems for Tdcads is also provided.« less

  9. Aerosol Oxidation Speeds Up in Smoggy Air

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Aerosol Oxidation Speeds Up in Smoggy Air Aerosol Oxidation Speeds Up in Smoggy Air Print Wednesday, 17 February 2016 11:37 Organic aerosols (nanometer-sized liquid or solid ...

  10. First observations of tracking clouds using scanning ARM cloud radars

    SciTech Connect (OSTI)

    Borque, Paloma; Giangrande, Scott; Kollias, Pavlos

    2014-12-01

    Tracking clouds using scanning cloud radars can help to document the temporal evolution of cloud properties well before large drop formation (‘‘first echo’’). These measurements complement cloud and precipitation tracking using geostationary satellites and weather radars. Here, two-dimensional (2-D) Along-Wind Range Height Indicator (AW-RHI) observations of a population of shallow cumuli (with and without precipitation) from the 35-GHz scanning ARM cloud radar (SACR) at the DOE Atmospheric Radiation Measurements (ARM) program Southern Great Plains (SGP) site are presented. Observations from the ARM SGP network of scanning precipitation radars are used to provide the larger scale context of the cloud field and to highlight the advantages of the SACR to detect the numerous, small, non-precipitating cloud elements. A new Cloud Identification and Tracking Algorithm (CITA) is developed to track cloud elements. In CITA, a cloud element is identified as a region having a contiguous set of pixels exceeding a preset reflectivity and size threshold. The high temporal resolution of the SACR 2-D observations (30 sec) allows for an area superposition criteria algorithm to match cloud elements at consecutive times. Following CITA, the temporal evolution of cloud element properties (number, size, and maximum reflectivity) is presented. The vast majority of the designated elements during this cumulus event were short-lived non-precipitating clouds having an apparent life cycle shorter than 15 minutes. The advantages and disadvantages of cloud tracking using an SACR are discussed.

  11. First observations of tracking clouds using scanning ARM cloud radars

    SciTech Connect (OSTI)

    Borque, Paloma; Giangrande, Scott; Kollias, Pavlos

    2014-12-01

    Tracking clouds using scanning cloud radars can help to document the temporal evolution of cloud properties well before large drop formation (first echo). These measurements complement cloud and precipitation tracking using geostationary satellites and weather radars. Here, two-dimensional (2-D) Along-Wind Range Height Indicator (AW-RHI) observations of a population of shallow cumuli (with and without precipitation) from the 35-GHz scanning ARM cloud radar (SACR) at the DOE Atmospheric Radiation Measurements (ARM) program Southern Great Plains (SGP) site are presented. Observations from the ARM SGP network of scanning precipitation radars are used to provide the larger scale context of the cloud field and to highlight the advantages of the SACR to detect the numerous, small, non-precipitating cloud elements. A new Cloud Identification and Tracking Algorithm (CITA) is developed to track cloud elements. In CITA, a cloud element is identified as a region having a contiguous set of pixels exceeding a preset reflectivity and size threshold. The high temporal resolution of the SACR 2-D observations (30 sec) allows for an area superposition criteria algorithm to match cloud elements at consecutive times. Following CITA, the temporal evolution of cloud element properties (number, size, and maximum reflectivity) is presented. The vast majority of the designated elements during this cumulus event were short-lived non-precipitating clouds having an apparent life cycle shorter than 15 minutes. The advantages and disadvantages of cloud tracking using an SACR are discussed.

  12. ARM - Field Campaign - Aerosol IOP

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ... Analyzer Order Data Arnott Desert Research Institute - airborne photo-acoustic aerosol extinction Order Data Bucholtz Aircraft Solar and IR Radiometers Order Data Jonsson Passive ...

  13. ARM Aerosol Working Group Meeting

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    - all sites * Aerosol Sampling - SGP, NSA, AMF - scattering, absorption, number, size ... (Germany, 2007) * Near Future: - ISDAC (NSA, 2008) - AMF (China, 2008) AWG Research ...

  14. On the characteristics of aerosol indirect effect based on dynamic regimes in global climate models

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Zhang, Shipeng; Wang, Minghuai; Ghan, Steven J.; Ding, Aijun; Wang, Hailong; Zhang, Kai; Neubauer, David; Lohmann, Ulrike; Ferrachat, Sylvaine; Takeamura, Toshihiko; et al

    2016-03-04

    Aerosol–cloud interactions continue to constitute a major source of uncertainty for the estimate of climate radiative forcing. The variation of aerosol indirect effects (AIE) in climate models is investigated across different dynamical regimes, determined by monthly mean 500 hPa vertical pressure velocity (ω500), lower-tropospheric stability (LTS) and large-scale surface precipitation rate derived from several global climate models (GCMs), with a focus on liquid water path (LWP) response to cloud condensation nuclei (CCN) concentrations. The LWP sensitivity to aerosol perturbation within dynamic regimes is found to exhibit a large spread among these GCMs. It is in regimes of strong large-scale ascentmore » (ω500  <  −25 hPa day−1) and low clouds (stratocumulus and trade wind cumulus) where the models differ most. Shortwave aerosol indirect forcing is also found to differ significantly among different regimes. Shortwave aerosol indirect forcing in ascending regimes is close to that in subsidence regimes, which indicates that regimes with strong large-scale ascent are as important as stratocumulus regimes in studying AIE. It is further shown that shortwave aerosol indirect forcing over regions with high monthly large-scale surface precipitation rate (> 0.1 mm day−1) contributes the most to the total aerosol indirect forcing (from 64 to nearly 100 %). Results show that the uncertainty in AIE is even larger within specific dynamical regimes compared to the uncertainty in its global mean values, pointing to the need to reduce the uncertainty in AIE in different dynamical regimes.« less

  15. Collaborative research. Study of aerosol sources and processing at the GVAX Pantnagar Supersite

    SciTech Connect (OSTI)

    Worsnop, Doug; Volkamer, Rainer

    2012-08-13

    The Two Column Aerosol Project (TCAP) investigated uncertainties in the aerosol direct effect in the northern hemisphere mid-latitudes. The University of Colorado 2D-MAX-DOAS and LED-CE-DOAS instruments were collocated with DOE’s Atmospheric Radiation Measurement (ARM) Mobile Facility (AMF) and Mobile Aerosol Observing System (MAOS) during the TCAP-1 campaign at Cape Cod, MA (1 July to 13 August 2012). We have performed atmospheric radiation closure studies to evaluate the use of a novel parameter, i.e., the Raman Scattering Probability (RSP). We have performed first measurements of RSP almucantar scans, and measure RSP in spectra of scattered solar photons at 350nm and 430nm. Radiative Transfer Modelling of RSP demonstrate that the RSP measurement is maximally sensitive to infer even extremely low aerosol optical depth (AOD < 0.01) reliably by DOAS at low solar relative azimuth angles. We further assess the role of elevated aerosol layers on near surface observations of oxygen collision complexes, O 2-O2. Elevated aerosol layers modify the near surface absorption of O2-O2 and RSP. The combination of RSP and O2-O2 holds largely unexplored potential to better constrain elevated aerosol layers and measure column aerosol optical properties such as aerosol effective radius, extinction, aerosol phase functions and refractive indices. The TCAP deployment also provides a time series of reactive trace gas vertical profiles, i.e., nitrogen dioxide (NO2) and glyoxal (C2H2O2), which are measured simultaneously with the aerosol optical properties by DOAS. NO2 is an important precursor for ozone (O3) that modifies oxidative capacity. Glyoxal modifies oxidative capacity and is a source for brown carbon by forming secondary organic aerosol (SOA) via multiphase reactions in aerosol and cloud water. We have performed field measurements of these gases

  16. ARM: 10-minute TEMPORARY Raman Lidar: aerosol extinction profiles and aerosol optical thickness, from first Ferrare algorithm

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Sivaraman, Chitra; Flynn, Connor

    10-minute TEMPORARY Raman Lidar: aerosol extinction profiles and aerosol optical thickness, from first Ferrare algorithm

  17. ARM: 10-minute TEMPORARY Raman Lidar: aerosol extinction profiles and aerosol optical thickness, from first Ferrare algorithm

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Sivaraman, Chitra; Flynn, Connor

    2010-12-15

    10-minute TEMPORARY Raman Lidar: aerosol extinction profiles and aerosol optical thickness, from first Ferrare algorithm

  18. Composition and Reactions of Atmospheric Aerosol Particles

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Composition and Reactions of Atmospheric Aerosol Particles Print Microscopic aerosol particles in the atmosphere contain carbonaceous components from mineral dust and combustion...

  19. Aerosol Oxidation Speeds Up in Smoggy Air

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Aerosol Oxidation Speeds Up in Smoggy Air Print Organic aerosols (nanometer-sized liquid or solid particles suspended in air) are important constituents of the troposphere, and ...

  20. Uncertainties in global aerosol simulations: Assessment using...

    Office of Scientific and Technical Information (OSTI)

    Title: Uncertainties in global aerosol simulations: Assessment using three meteorological data sets Current global aerosol models use different physical and chemical schemes and 4 ...

  1. ARM - Evaluation Product - Organic Aerosol Component VAP

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    mass spectral matrix data collected by the aerosol chemical speciation monitor and multivariate analysis to obtain an estimate of the types of organic aerosols. Currently, time...

  2. Science on the Hill: Methane cloud hunting

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Methane cloud hunting Science on the Hill: Methane cloud hunting Los Alamos researchers go ... Science on the Hill: Methane cloud hunting When our team from Los Alamos National ...

  3. Evaluation of high‐level clouds in cloud resolving model...

    Office of Scientific and Technical Information (OSTI)

    Evaluation of high-level clouds in cloud resolving model 10.10022015MS000478 simulations with ARM and KWAJEX observations Key Points: * Two-moment microphysics improves simulated ...

  4. Chemical Composition and Sources of Coastal Marine Aerosol Particles during the 2008 VOCALS-REx Campaign

    SciTech Connect (OSTI)

    Lee, Y.- N.; Springston, S.; Jayne, John T.; Wang, Jian; Hubbe, John M.; Senum, Gunnar I.; Kleinman, Lawrence I.; Daum, Peter H.

    2014-05-23

    The chemical composition of aerosol particles (Dp 1.5 ?m) was measured over the southeast Pacific Ocean during the VAMOS (Variability of the American Monsoon Systems) Ocean-Cloud-Atmosphere-Land Study Regional Experiment (VOCALS-Rex) between 16 October and 15 November 2008 using the US Department of Energy (DOE) G-1 aircraft. The objective of these flights was to gain an understanding of the sources and evolution of these aerosols, and of how they interact with the marine stratus cloud layer that prevails in this region of the globe. Our measurements showed that the marine boundary layer (MBL) aerosol mass was dominated by non-sea-salt SO2?4, followed by Na+, Cl?, Org (total organics), NH+4 , and NO?3 , in decreasing order of importance; CH3SO?3 (MSA), Ca2+, and K+ rarely exceeded their limits of detection. Aerosols were strongly acidic with a NH+4 to SO2?4 equivalents ratio typically < 0.3. Sea-salt aerosol (SSA) particles, represented by NaCl, exhibited Cl? deficits caused by both HNO3 and H2SO4, but for the most part were externally mixed with particles, mainly SO2?4. SSA contributed only a small fraction of the total accumulation mode particle number concentration. It was inferred that all aerosol species (except SSA) were of predominantly continental origin because of their strong land-to-sea concentration gradient. Comparison of relative changes in median values suggests that (1) an oceanic source of NH3 is present between 72 W and 76 W, (2) additional organic aerosols from biomass burns or biogenic precursors were emitted from coastal regions south of 31 S, with possible cloud processing, and (3) free tropospheric (FT) contributions to MBL gas and aerosol concentrations were negligible. The very low levels of CH3SO?3 observed as well as the correlation between SO2?4 and NO?3 (which is thought primarily anthropogenic) suggest a limited contribution of DMS to SO2?4 aerosol production during VOCALS.

  5. Satellite estimates of precipitation susceptibility in low-level marine stratiform clouds

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Terai, C. R.; Wood, R.; Kubar, T. L.

    2015-09-05

    Quantifying the sensitivity of warm rain to aerosols is important for constraining climate model estimates of aerosol indirect effects. In this study, the precipitation sensitivity to cloud droplet number concentration (Nd) in satellite retrievals is quantified by applying the precipitation susceptibility metric to a combined CloudSat/Moderate Resolution Imaging Spectroradiometer data set of stratus and stratocumulus clouds that cover the tropical and subtropical Pacific Ocean and Gulf of Mexico. We note that consistent with previous observational studies of marine stratocumulus, precipitation susceptibility decreases with increasing liquid water path (LWP), and the susceptibility of the mean precipitation rate R is nearly equalmore » to the sum of the susceptibilities of precipitation intensity and of probability of precipitation. Consistent with previous modeling studies, the satellite retrievals reveal that precipitation susceptibility varies not only with LWP but also with Nd. Puzzlingly, negative values of precipitation susceptibility are found at low LWP and high Nd. There is marked regional variation in precipitation susceptibility values that cannot simply be explained by regional variations in LWP and Nd. This suggests other controls on precipitation apart from LWP and Nd and that precipitation susceptibility will need to be quantified and understood at the regional scale when relating to its role in controlling possible aerosol-induced cloud lifetime effects.« less

  6. Satellite estimates of precipitation susceptibility in low-level marine stratiform clouds

    SciTech Connect (OSTI)

    Terai, C. R.; Wood, R.; Kubar, T. L.

    2015-09-05

    Quantifying the sensitivity of warm rain to aerosols is important for constraining climate model estimates of aerosol indirect effects. In this study, the precipitation sensitivity to cloud droplet number concentration (Nd) in satellite retrievals is quantified by applying the precipitation susceptibility metric to a combined CloudSat/Moderate Resolution Imaging Spectroradiometer data set of stratus and stratocumulus clouds that cover the tropical and subtropical Pacific Ocean and Gulf of Mexico. We note that consistent with previous observational studies of marine stratocumulus, precipitation susceptibility decreases with increasing liquid water path (LWP), and the susceptibility of the mean precipitation rate R is nearly equal to the sum of the susceptibilities of precipitation intensity and of probability of precipitation. Consistent with previous modeling studies, the satellite retrievals reveal that precipitation susceptibility varies not only with LWP but also with Nd. Puzzlingly, negative values of precipitation susceptibility are found at low LWP and high Nd. There is marked regional variation in precipitation susceptibility values that cannot simply be explained by regional variations in LWP and Nd. This suggests other controls on precipitation apart from LWP and Nd and that precipitation susceptibility will need to be quantified and understood at the regional scale when relating to its role in controlling possible aerosol-induced cloud lifetime effects.

  7. Composition of carbonaceous smoke particles from prescribed burning of a Canadian boreal forest: 1. Organic aerosol characterization by gas chromatography

    SciTech Connect (OSTI)

    Mazurek, M.A.; Laterza, C.; Newman, L.; Daum, P.; Cofer, W.R. III; Levine, J.S.; Winstead, E.L.

    1995-06-01

    In this study we examine the molecular organic constituents (C8 to C40 lipid compounds) collected as smoke particles from a Canadian boreal forest prescribed burn. Of special interest are (1) the molecular identity of polar organic aerosols, and (2) the amount of polar organic matter relative to the total mass of aerosol particulate carbon. Organic extracts of smoke aerosol particles show complex distributions of the lipid compounds when analyzed by capillary gas chromatography/mass spectrometry. The molecular constituents present as smoke aerosol are grouped into non-polar (hydrocarbons) and polar {minus}2 oxygen atoms) subtractions. The dominant chemical species found in the boreal forest smoke aerosol are unaltered resin compounds (C20 terpenes) which are abundant in unburned conifer wood, plus thermally altered wood lignins and other polar aromatic hydrocarbons. Our results show that smoke aerosols contain molecular tracers which are related to the biofuel consumed. These smoke tracers can be related structurally back to the consumed softwood and hardwood vegetation. In addition, combustion of boreal forest materials produces smoke aerosol particles that are both oxygen-rich and chemically complex, yielding a carbonaceous aerosol matrix that is enriched in polar substances. As a consequence, emissions of carbonaceous smoke particles from large-scale combustion of boreal forest land may have a disproportionate effect on regional atmospheric chemistry and on cloud microphysical processes.

  8. Opaque cloud detection

    DOE Patents [OSTI]

    Roskovensky, John K.

    2009-01-20

    A method of detecting clouds in a digital image comprising, for an area of the digital image, determining a reflectance value in at least three discrete electromagnetic spectrum bands, computing a first ratio of one reflectance value minus another reflectance value and the same two values added together, computing a second ratio of one reflectance value and another reflectance value, choosing one of the reflectance values, and concluding that an opaque cloud exists in the area if the results of each of the two computing steps and the choosing step fall within three corresponding predetermined ranges.

  9. Bringing Clouds into Focus

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Bringing Clouds into Focus Bringing Clouds into Focus A New Global Climate Model May Reduce the Uncertainty of Climate Forecasting May 11, 2010 Contact: John Hules, JAHules@lbl.gov , +1 510 486 6008 Randall-fig4.png The large data sets generated by the GCRM require new analysis and visualization capabilities. This 3D plot of vorticity isosurfaces was developed using VisIt, a 3D visualization tool with a parallel distributed architecture, which is being extended to support the geodesic grid used

  10. Atmospheric Radiation Measurement (ARM) Data from Steamboat Springs, Colorado, for the Storm Peak Laboratory Cloud Property Validation Experiment (STORMVEX)

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    In October 2010, the initial deployment of the second ARM Mobile Facility (AMF2) took place at Steamboat Springs, Colorado, for the Storm Peak Laboratory Cloud Property Validation Experiment (STORMVEX). The objective of this field campaign was to obtain data about liquid and mixed-phase clouds using AMF2 instruments in conjunction with Storm Peak Laboratory (located at an elevation of 3220 meters on Mt. Werner), a cloud and aerosol research facility operated by the Desert Research Institute. STORMVEX datasets are freely available for viewing and download. Users are asked to register with the ARM Archive; the user's email address is used from that time forward as the login name.

  11. Cloud Based Applications and Platforms (Presentation)

    SciTech Connect (OSTI)

    Brodt-Giles, D.

    2014-05-15

    Presentation to the Cloud Computing East 2014 Conference, where we are highlighting our cloud computing strategy, describing the platforms on the cloud (including Smartgrid.gov), and defining our process for implementing cloud based applications.

  12. FY 2011 Second Quarter: Demonstration of New Aerosol Measurement Verification Testbed for Present-Day Global Aerosol Simulations

    SciTech Connect (OSTI)

    Koch, D

    2011-03-20

    The regional-scale Weather Research and Forecasting (WRF) model is being used by a DOE Earth System Modeling (ESM) project titled Improving the Characterization of Clouds, Aerosols and the Cryosphere in Climate Models to evaluate the performance of atmospheric process modules that treat aerosols and aerosol radiative forcing in the Arctic. We are using a regional-scale modeling framework for three reasons: (1) It is easier to produce a useful comparison to observations with a high resolution model; (2) We can compare the behavior of the CAM parameterization suite with some of the more complex and computationally expensive parameterizations used in WRF; (3) we can explore the behavior of this parameterization suite at high resolution. Climate models like the Community Atmosphere Model version 5 (CAM5) being used within the Community Earth System Model (CESM) will not likely be run at mesoscale spatial resolutions (1020 km) until 510 years from now. The performance of the current suite of physics modules in CAM5 at such resolutions is not known, and current computing resources do not permit high-resolution global simulations to be performed routinely. We are taking advantage of two tools recently developed under PNNL Laboratory Directed Research and Development (LDRD) projects for this activity. The first is the Aerosol Modeling Testbed (Fast et al., 2011b), a new computational framework designed to streamline the process of testing and evaluating aerosol process modules over a range of spatial and temporal scales. The second is the CAM5 suite of physics parameterizations that have been ported into WRF so that their performance and scale dependency can be quantified at mesoscale spatial resolutions (Gustafson et al., 2010; with more publications in preparation).

  13. TWP Island Cloud Trail Studies

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    These island cloud trails have been observed from both the islands of Nauru and Manus, Papua New Guinea. Figure 2 shows an island cloud at Manus observed from MTI and from the ...

  14. Predicting and validating the tracking of a Volcanic Ash Cloud during the 2006 Eruption of Mt. Augustine Volcano

    SciTech Connect (OSTI)

    Webley, Peter W.; Atkinson, D.; Collins, Richard L.; Dean, K.; Fochesatto, J.; Sassen, Kenneth; Cahill, Catherine F.; Prata, A.; Flynn, Connor J.; Mizutani, K.

    2008-11-01

    On 11 January 2006, Mount Augustine volcano in southern Alaska began erupting after 20-year repose. The Anchorage Forecast Office of the National Weather Service (NWS) issued an advisory on 28 January for Kodiak City. On 31 January, Alaska Airlines cancelled all flights to and from Anchorage after multiple advisories from the NWS for Anchorage and the surrounding region. The Alaska Volcano Observatory (AVO) had reported the onset of the continuous eruption. AVO monitors the approximately 100 active volcanoes in the Northern Pacific. Ash clouds from these volcanoes can cause serious damage to an aircraft and pose a serious threat to the local communities, and to transcontinental air traffic throughout the Arctic and sub-Arctic region. Within AVO, a dispersion model has been developed to track the dispersion of volcanic ash clouds. The model, Puff, was used operational by AVO during the Augustine eruptive period. Here, we examine the dispersion of a volcanic ash cloud from Mount Augustine across Alaska from 29 January through the 2 February 2006. We present the synoptic meteorology, the Puff predictions, and measurements from aerosol samplers, laser radar (or lidar) systems, and satellites. UAF aerosol samplers revealed the presence of volcanic aerosols at the surface at sites where Puff predicted the ash clouds movement. Remote sensing satellite data showed the development of the ash cloud in close proximity to the volcano and a sulfur-dioxide cloud further from the volcano consistent with the Puff predictions. Lidars showed the presence of volcanic aerosol with consistent characteristics aloft over Alaska and were capable of detecting the aerosol, even in the presence of scattered clouds and where the cloud is too thin/disperse to be detected by remote sensing satellite data. The lidar measurements revealed the different trajectories of ash consistent with the Puff predictions. Dispersion models provide a forecast of volcanic ash cloud movement that might be

  15. ARM - Measurement - Images of Clouds

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    govMeasurementsImages of Clouds ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Images of Clouds Digital images of cloud scenes (various formats) from satellite, aircraft, and ground-based platforms. Categories Cloud Properties Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a

  16. ARM - Measurement - Total cloud water

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    cloud water ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Total cloud water The total concentration (mass/vol) of ice and liquid water particles in a cloud; this includes condensed water content (CWC). Categories Cloud Properties Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a

  17. Microphysical Properties of Single and Mixed-Phase Arctic Clouds Derived from AERI Observations

    SciTech Connect (OSTI)

    Turner, David D.

    2003-06-01

    A novel new approach to retrieve cloud microphysical properties from mixed-phase clouds is presented. This algorithm retrieves cloud optical depth, ice fraction, and the effective size of the water and ice particles from ground-based, high-resolution infrared radiance observations. The theoretical basis is that the absorption coefficient of ice is stronger than that of liquid water from 10-13 mm, whereas liquid water is more absorbing than ice from 16-25 um. However, due to strong absorption in the rotational water vapor absorption band, the 16-25 um spectral region becomes opaque for significant water vapor burdens (i.e., for precipitable water vapor amounts over approximately 1 cm). The Arctic is characterized by its dry and cold atmosphere, as well as a preponderance of mixed-phase clouds, and thus this approach is applicable to Arctic clouds. Since this approach uses infrared observations, cloud properties are retrieved at night and during the long polar wintertime period. The analysis of the cloud properties retrieved during a 7 month period during the Surface Heat Budget of the Arctic (SHEBA) experiment demonstrates many interesting features. These results show a dependence of the optical depth on cloud phase, differences in the mode radius of the water droplets in liquid-only and mid-phase clouds, a lack of temperature dependence in the ice fraction for temperatures above 240 K, seasonal trends in the optical depth with the clouds being thinner in winter and becoming more optically thick in the late spring, and a seasonal trend in the effective size of the water droplets in liquid-only and mixed-phase clouds that is most likely related to aerosol concentration.

  18. Use of ARM Mobile Facility (AMF) Data to Study Aerosol Indirect Effects in China

    SciTech Connect (OSTI)

    Li, Zhanqing

    2012-12-19

    General goals: 1) Facilitating the deployment of the ARM Mobile Facility (AMF) and Ancillary Facility (AAF) in China in 2008, 2) Processing, retrieving, improving and analyzing observation data from ground-based, air-borne and space-borne instruments; 3) Conducting a series of studies to gain insights into the direct and indirect effects of these aerosols on radiation, clouds, and precipitation using both

  19. First observations of tracking clouds using scanning ARM cloud radars

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Borque, Paloma; Giangrande, Scott; Kollias, Pavlos

    2014-12-01

    Tracking clouds using scanning cloud radars can help to document the temporal evolution of cloud properties well before large drop formation (‘‘first echo’’). These measurements complement cloud and precipitation tracking using geostationary satellites and weather radars. Here, two-dimensional (2-D) Along-Wind Range Height Indicator (AW-RHI) observations of a population of shallow cumuli (with and without precipitation) from the 35-GHz scanning ARM cloud radar (SACR) at the DOE Atmospheric Radiation Measurements (ARM) program Southern Great Plains (SGP) site are presented. Observations from the ARM SGP network of scanning precipitation radars are used to provide the larger scale context of the cloud fieldmore » and to highlight the advantages of the SACR to detect the numerous, small, non-precipitating cloud elements. A new Cloud Identification and Tracking Algorithm (CITA) is developed to track cloud elements. In CITA, a cloud element is identified as a region having a contiguous set of pixels exceeding a preset reflectivity and size threshold. The high temporal resolution of the SACR 2-D observations (30 sec) allows for an area superposition criteria algorithm to match cloud elements at consecutive times. Following CITA, the temporal evolution of cloud element properties (number, size, and maximum reflectivity) is presented. The vast majority of the designated elements during this cumulus event were short-lived non-precipitating clouds having an apparent life cycle shorter than 15 minutes. The advantages and disadvantages of cloud tracking using an SACR are discussed.« less

  20. ARM - Campaign Instrument - drum-aerosol

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    govInstrumentsdrum-aerosol Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign Instrument : Drum Aerosol Sampler (DRUM-AEROSOL) Instrument Categories Aerosols Campaigns Aerosol IOP [ Download Data ] Southern Great Plains, 2003.05.01 - 2003.05.31 Primary Measurements Taken The following measurements are those considered scientifically relevant. Refer to the datastream (netcdf) file headers for the list of all available measurements, including

  1. Carbonaceous Aerosols and Radiative Effects Study

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Carbonaceous Aerosols and Radiative Effects Study Science Objective This field campaign is designed to increase scientific knowledge about the evolution of black carbon, primary organic aerosols (POA), and secondary organic aerosols (SOA) from both man-made and biogenic sources. Black carbon and primary organic aerosols are emitted directly into the atmosphere through diesel and gasoline vehicle exhaust, as well as during meat cooking and biomass burning; secondary organic aerosols are formed

  2. eDPS Aerosol Collection

    SciTech Connect (OSTI)

    Venzie, J.

    2015-10-13

    The eDPS Aerosol Collection project studies the fundamental physics of electrostatic aerosol collection for national security applications. The interpretation of aerosol data requires understanding and correcting for biases introduced from particle genesis through collection and analysis. The research and development undertaken in this project provides the basis for both the statistical correction of existing equipment and techniques; as well as, the development of new collectors and analytical techniques designed to minimize unwanted biases while improving the efficiency of locating and measuring individual particles of interest.

  3. Raman Lidar Measurements of Aerosols and Water Vapor During the...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Raman Lidar Measurements of Aerosols and Water Vapor During the May 2003 Aerosol IOP R. A. ... Marina, California Abstract Raman lidar water vapor and aerosol extinction profiles ...

  4. ARM - Field Campaign - Carbonaceous Aerosol and Radiative Effects...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ARM Data Discovery Browse Data Related Campaigns Carbonaceous Aerosol and Radiation ... Carbonaceous Aerosol and Radiation Effects Study (CARES) Photo-Acoustic Aerosol Light ...

  5. ARM: Aerosol Observing System (AOS): auxiliary data (Dataset...

    Office of Scientific and Technical Information (OSTI)

    Aerosol Observing System (AOS): auxiliary data Title: ARM: Aerosol Observing System (AOS): auxiliary data Aerosol Observing System (AOS): auxiliary data Authors: Ogren, John ; ...

  6. Toward a Minimal Representation of Aerosols in Climate Models...

    Office of Scientific and Technical Information (OSTI)

    and external mixing between aerosol components, treating numerous complicated aerosol ... black carbon (BC) with other aerosol components, merging of the MAM7 fine dust and fine ...

  7. ARM - Field Campaign - MASRAD: Cloud Study from the 2NFOV at Pt. Reyes

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Field Campaign govCampaignsMASRAD: Cloud Study from the 2NFOV at Pt. Reyes Field Campaign Campaign Links AMF Point Reyes Website ARM Data Discovery Browse Data Related Campaigns MArine Stratus Radiation Aerosol and Drizzle (MASRAD) IOP 2005.03.14, Miller, AMF Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : MASRAD: Cloud Study from the 2NFOV at Pt. Reyes Field Campaign 2005.06.02 - 2005.09.30 Lead Scientist : Warren Wiscombe For

  8. ARM - Field Campaign - MASRAD: Pt. Reyes Stratus Cloud and Drizzle Study

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    govCampaignsMASRAD: Pt. Reyes Stratus Cloud and Drizzle Study Campaign Links AMF Point Reyes Website ARM Data Discovery Browse Data Related Campaigns MArine Stratus Radiation Aerosol and Drizzle (MASRAD) IOP 2005.03.14, Miller, AMF Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : MASRAD: Pt. Reyes Stratus Cloud and Drizzle Study 2005.07.07 - 2005.07.31 Lead Scientist : Richard Coulter For data sets, see below. Abstract The primary goal

  9. Stratospheric aerosol geoengineering

    SciTech Connect (OSTI)

    Robock, Alan

    2015-03-30

    The Geoengineering Model Intercomparison Project, conducting climate model experiments with standard stratospheric aerosol injection scenarios, has found that insolation reduction could keep the global average temperature constant, but global average precipitation would reduce, particularly in summer monsoon regions around the world. Temperature changes would also not be uniform; the tropics would cool, but high latitudes would warm, with continuing, but reduced sea ice and ice sheet melting. Temperature extremes would still increase, but not as much as without geoengineering. If geoengineering were halted all at once, there would be rapid temperature and precipitation increases at 5–10 times the rates from gradual global warming. The prospect of geoengineering working may reduce the current drive toward reducing greenhouse gas emissions, and there are concerns about commercial or military control. Because geoengineering cannot safely address climate change, global efforts to reduce greenhouse gas emissions and to adapt are crucial to address anthropogenic global warming.

  10. ARM - Measurement - Aerosol optical depth

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Sky-Scanning, Sun Tracking Atmospheric Research SAM : Sun and Aureole Measurement UAV-GNAT : UAV-General Atomics GNAT Value-Added Products AOD : Aerosol Optical Depth, derived from ...

  11. ARM - Measurement - Aerosol backscattered radiation

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Aerosol backscattered radiation The scattering of radiant energy into the hemisphere of space bounded by a ...

  12. Evaluation of high-level clouds in cloud resolving model simulations...

    Office of Scientific and Technical Information (OSTI)

    Title: Evaluation of high-level clouds in cloud resolving model simulations with ARM and KWAJEX observations: HIGH CLOUD IN CRM Authors: Liu, Zheng 1 ; Muhlbauer, Andreas 2 ; ...

  13. Linearity of Climate Response to Increases in Black Carbon Aerosols

    SciTech Connect (OSTI)

    Mahajan, Salil; Evans, Katherine J.; Hack, James J.; Truesdale, John

    2013-04-19

    The impact of absorbing aerosols on global climate are not completely understood. Here, we present results of idealized experiments conducted with the Community Atmosphere Model (CAM4) coupled to a slab ocean model (CAM4-SOM) to simulate the climate response to increases in tropospheric black carbon aerosols (BC) by direct and semi-direct effects. CAM4-SOM was forced with 0, 1x, 2x, 5x and 10x an estimate of the present day concentration of BC while maintaining their estimated present day global spatial and vertical distribution. The top of the atmosphere (TOA) radiative forcing of BC in these experiments is positive (warming) and increases linearly as the BC burden increases. The total semi-direct effect for the 1x experiment is positive but becomes increasingly negative for higher BC concentrations. The global average surface temperature response is found to be a linear function of the TOA radiative forcing. The climate sensitivity to BC from these experiments is estimated to be 0.42 K $ W^{-1} m^{2}$ when the semi-direct effects are accounted for and 0.22 K $ W^{-1} m^{2}$ with only the direct effects considered. Global average precipitation decreases linearly as BC increases, with a precipitation sensitivity to atmospheric absorption of 0.4 $\\%$ $W^{-1}m^{2}$ . The hemispheric asymmetry of BC also causes an increase in southward cross-equatorial heat transport and a resulting northward shift of the inter-tropical convergence zone in the simulations at a rate of 4$^{\\circ}$N $ PW^{-1}$. Global average mid- and high-level clouds decrease, whereas the low-level clouds increase linearly with BC. The increase in marine stratocumulus cloud fraction over the south tropical Atlantic is caused by increased BC-induced diabatic heating of the free troposphere.

  14. RACORO continental boundary layer cloud investigations. Part I: Case study development and ensemble large-scale forcings

    SciTech Connect (OSTI)

    Vogelmann, Andrew M.; Fridlind, Ann M.; Toto, Tami; Endo, Satoshi; Lin, Wuyin; Wang, Jian; Feng, Sha; Zhang, Yunyan; Turner, David D.; Liu, Yangang; Li, Zhijin; Xie, Shaocheng; Ackerman, Andrew S.; Zhang, Minghua; Khairoutdinov, Marat

    2015-06-19

    Observation-based modeling case studies of continental boundary layer clouds have been developed to study cloudy boundary layers, aerosol influences upon them, and their representation in cloud- and global-scale models. Three 60-hour case study periods span the temporal evolution of cumulus, stratiform, and drizzling boundary layer cloud systems, representing mixed and transitional states rather than idealized or canonical cases. Based on in-situ measurements from the RACORO field campaign and remote-sensing observations, the cases are designed with a modular configuration to simplify use in large-eddy simulations (LES) and single-column models. Aircraft measurements of aerosol number size distribution are fit to lognormal functions for concise representation in models. Values of the aerosol hygroscopicity parameter, ?, are derived from observations to be ~0.10, which are lower than the 0.3 typical over continents and suggestive of a large aerosol organic fraction. Ensemble large-scale forcing datasets are derived from the ARM variational analysis, ECMWF forecasts, and a multi-scale data assimilation system. The forcings are assessed through comparison of measured bulk atmospheric and cloud properties to those computed in 'trial' large-eddy simulations, where more efficient run times are enabled through modest reductions in grid resolution and domain size compared to the full-sized LES grid. Simulations capture many of the general features observed, but the state-of-the-art forcings were limited at representing details of cloud onset, and tight gradients and high-resolution transients of importance. Methods for improving the initial conditions and forcings are discussed. The cases developed are available to the general modeling community for studying continental boundary clouds.

  15. RACORO continental boundary layer cloud investigations. Part I: Case study development and ensemble large-scale forcings

    SciTech Connect (OSTI)

    Vogelmann, Andrew M.; Fridlind, Ann M.; Toto, Tami; Endo, Satoshi; Lin, Wuyin; Wang, Jian; Feng, Sha; Zhang, Yunyan; Turner, David D.; Liu, Yangang; Li, Zhijin; Xie, Shaocheng; Ackerman, Andrew S.; Zhang, Minghua; Khairoutdinov, Marat

    2015-06-19

    Observation-based modeling case studies of continental boundary layer clouds have been developed to study cloudy boundary layers, aerosol influences upon them, and their representation in cloud- and global-scale models. Three 60-hour case study periods span the temporal evolution of cumulus, stratiform, and drizzling boundary layer cloud systems, representing mixed and transitional states rather than idealized or canonical cases. Based on in-situ measurements from the RACORO field campaign and remote-sensing observations, the cases are designed with a modular configuration to simplify use in large-eddy simulations (LES) and single-column models. Aircraft measurements of aerosol number size distribution are fit to lognormal functions for concise representation in models. Values of the aerosol hygroscopicity parameter, κ, are derived from observations to be ~0.10, which are lower than the 0.3 typical over continents and suggestive of a large aerosol organic fraction. Ensemble large-scale forcing datasets are derived from the ARM variational analysis, ECMWF forecasts, and a multi-scale data assimilation system. The forcings are assessed through comparison of measured bulk atmospheric and cloud properties to those computed in 'trial' large-eddy simulations, where more efficient run times are enabled through modest reductions in grid resolution and domain size compared to the full-sized LES grid. Simulations capture many of the general features observed, but the state-of-the-art forcings were limited at representing details of cloud onset, and tight gradients and high-resolution transients of importance. Methods for improving the initial conditions and forcings are discussed. The cases developed are available to the general modeling community for studying continental boundary clouds.

  16. RACORO continental boundary layer cloud investigations. Part I: Case study development and ensemble large-scale forcings

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Vogelmann, Andrew M.; Fridlind, Ann M.; Toto, Tami; Endo, Satoshi; Lin, Wuyin; Wang, Jian; Feng, Sha; Zhang, Yunyan; Turner, David D.; Liu, Yangang; et al

    2015-06-19

    Observation-based modeling case studies of continental boundary layer clouds have been developed to study cloudy boundary layers, aerosol influences upon them, and their representation in cloud- and global-scale models. Three 60-hour case study periods span the temporal evolution of cumulus, stratiform, and drizzling boundary layer cloud systems, representing mixed and transitional states rather than idealized or canonical cases. Based on in-situ measurements from the RACORO field campaign and remote-sensing observations, the cases are designed with a modular configuration to simplify use in large-eddy simulations (LES) and single-column models. Aircraft measurements of aerosol number size distribution are fit to lognormal functionsmore » for concise representation in models. Values of the aerosol hygroscopicity parameter, κ, are derived from observations to be ~0.10, which are lower than the 0.3 typical over continents and suggestive of a large aerosol organic fraction. Ensemble large-scale forcing datasets are derived from the ARM variational analysis, ECMWF forecasts, and a multi-scale data assimilation system. The forcings are assessed through comparison of measured bulk atmospheric and cloud properties to those computed in 'trial' large-eddy simulations, where more efficient run times are enabled through modest reductions in grid resolution and domain size compared to the full-sized LES grid. Simulations capture many of the general features observed, but the state-of-the-art forcings were limited at representing details of cloud onset, and tight gradients and high-resolution transients of importance. Methods for improving the initial conditions and forcings are discussed. The cases developed are available to the general modeling community for studying continental boundary clouds.« less

  17. Method for producing monodisperse aerosols

    DOE Patents [OSTI]

    Ortiz, Lawrence W.; Soderholm, Sidney C.

    1990-01-01

    An aerosol generator is described which is capable of producing a monodisperse aerosol within narrow limits utilizing an aqueous solution capable of providing a high population of seed nuclei and an organic solution having a low vapor pressure. The two solutions are cold nebulized, mixed, vaporized, and cooled. During cooling, particles of the organic vapor condense onto the excess seed nuclei, and grow to a uniform particle size.

  18. Testing ice microphysics parameterizations in the NCAR Community Atmospheric Model Version 3 using Tropical Warm Pool-International Cloud Experiment data

    SciTech Connect (OSTI)

    Wang, Weiguo; Liu, Xiaohong; Xie, Shaocheng; Boyle, Jim; McFarlane, Sally A.

    2009-07-23

    Here, cloud properties have been simulated with a new double-moment microphysics scheme under the framework of the single-column version of NCAR Community Atmospheric Model version 3 (CAM3). For comparison, the same simulation was made with the standard single-moment microphysics scheme of CAM3. Results from both simulations compared favorably with observations during the Tropical Warm Pool–International Cloud Experiment by the U.S. Department of Energy Atmospheric Radiation Measurement Program in terms of the temporal variation and vertical distribution of cloud fraction and cloud condensate. Major differences between the two simulations are in the magnitude and distribution of ice water content within the mixed-phase cloud during the monsoon period, though the total frozen water (snow plus ice) contents are similar. The ice mass content in the mixed-phase cloud from the new scheme is larger than that from the standard scheme, and ice water content extends 2 km further downward, which is in better agreement with observations. The dependence of the frozen water mass fraction on temperature from the new scheme is also in better agreement with available observations. Outgoing longwave radiation (OLR) at the top of the atmosphere (TOA) from the simulation with the new scheme is, in general, larger than that with the standard scheme, while the surface downward longwave radiation is similar. Sensitivity tests suggest that different treatments of the ice crystal effective radius contribute significantly to the difference in the calculations of TOA OLR, in addition to cloud water path. Numerical experiments show that cloud properties in the new scheme can respond reasonably to changes in the concentration of aerosols and emphasize the importance of correctly simulating aerosol effects in climate models for aerosol-cloud interactions. Further evaluation, especially for ice cloud properties based on in-situ data, is needed.

  19. Testing ice microphysics parameterizations in the NCAR Community Atmospheric Model Version 3 using Tropical Warm Pool-International Cloud Experiment data

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Wang, Weiguo; Liu, Xiaohong; Xie, Shaocheng; Boyle, Jim; McFarlane, Sally A.

    2009-07-23

    Here, cloud properties have been simulated with a new double-moment microphysics scheme under the framework of the single-column version of NCAR Community Atmospheric Model version 3 (CAM3). For comparison, the same simulation was made with the standard single-moment microphysics scheme of CAM3. Results from both simulations compared favorably with observations during the Tropical Warm Pool–International Cloud Experiment by the U.S. Department of Energy Atmospheric Radiation Measurement Program in terms of the temporal variation and vertical distribution of cloud fraction and cloud condensate. Major differences between the two simulations are in the magnitude and distribution of ice water content within themore » mixed-phase cloud during the monsoon period, though the total frozen water (snow plus ice) contents are similar. The ice mass content in the mixed-phase cloud from the new scheme is larger than that from the standard scheme, and ice water content extends 2 km further downward, which is in better agreement with observations. The dependence of the frozen water mass fraction on temperature from the new scheme is also in better agreement with available observations. Outgoing longwave radiation (OLR) at the top of the atmosphere (TOA) from the simulation with the new scheme is, in general, larger than that with the standard scheme, while the surface downward longwave radiation is similar. Sensitivity tests suggest that different treatments of the ice crystal effective radius contribute significantly to the difference in the calculations of TOA OLR, in addition to cloud water path. Numerical experiments show that cloud properties in the new scheme can respond reasonably to changes in the concentration of aerosols and emphasize the importance of correctly simulating aerosol effects in climate models for aerosol-cloud interactions. Further evaluation, especially for ice cloud properties based on in-situ data, is needed.« less

  20. GFDL ARM Project Technical Report: Using ARM Observations to Evaluate Cloud and Convection Parameterizations & Cloud-Convection-Radiation Interactions in the GFDL Atmospheric General Circulation Model

    SciTech Connect (OSTI)

    V. Ramaswamy; L. J. Donner; J-C. Golaz; S. A. Klein

    2010-06-17

    This report briefly summarizes the progress made by ARM postdoctoral fellow, Yanluan Lin, at GFDL during the period from October 2008 to present. Several ARM datasets have been used for GFDL model evaluation, understanding, and improvement. This includes a new ice fall speed parameterization with riming impact and its test in GFDL AM3, evaluation of model cloud and radiation diurnal and seasonal variation using ARM CMBE data, model ice water content evaluation using ARM cirrus data, and coordination of the TWPICE global model intercomparison. The work illustrates the potential and importance of ARM data for GCM evaluation, understanding, and ultimately, improvement of GCM cloud and radiation parameterizations. Future work includes evaluation and improvement of the new dynamicsPDF cloud scheme and aerosol activation in the GFDL model.

  1. Perturbed Physics Ensemble Simulations of Cirrus on the Cloud System-resolving Scale

    SciTech Connect (OSTI)

    Muhlbauer, Andreas; Berry, Elizabeth; Comstock, Jennifer M.; Mace, Gerald G.

    2014-04-16

    In this study, the effect of uncertainties in the parameterization of ice microphysical processes and initial conditions on the variability of cirrus microphysical and radiative properties are investigated in a series of cloud system-resolving perturbed physics ensemble (PPE) and initial condition ensemble (ICE) simulations. Three cirrus cases representative of mid-latitude, subtropical and tropical cirrus are examined. It is found that the variability in cirrus properties induced by perturbing uncertain parameters in ice microphysics parameterizations outweighs the variability induced by perturbing the initial conditions in midlatitude and subtropical cirrus. However, in tropical anvil cirrus the variability in the PPE and ICE simulations is about the same order of magnitude. The cirrus properties showing the largest sensitivity are ice water content (IWC) and cloud thickness whereas the averaged high cloud cover is only marginally affected. Changes in cirrus ice water path and outgoing longwave radiation are controlled primarily by changes in IWC and cloud thickness but not by changes is the averaged high cloud cover. The change in the vertical distribution of cloud fraction and cloud thickness is caused by changes in cirrus cloud base whereas cloud top is not sensitive to either perturbed physics or perturbed initial conditions. In all cirrus cases, the top three parameters controlling the microphysical variability and radiative impact of cirrus clouds are ice fall speeds, ice autoconversion size thresholds and heterogeneous ice nucleation. Changes in the ice deposition coefficient do not affect the ice water path and outgoing longwave radiation. Similarly, changes in the number concentration of aerosols available for homogeneous freezing have virtually no effect on the microphysical and radiative properties of midlatitude and subtropical cirrus but only little impact on tropical anvil cirrus. Overall, the sensitivity of cirrus microphysical and radiative

  2. Assessing Cloud Spatial and Vertical Distribution with Infrared Cloud Analyzer

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Cloud Spatial and Vertical Distribution with Infrared Cloud Analyzer I. Genkova and C. N. Long Pacific Northwest National Laboratory Richland, Washington T. Besnard ATMOS SARL Le Mans, France D. Gillotay Institute d'Aeronomie Spatiale de Belgique Brussels, Belgium Introduction In the effort to resolve uncertainties about global climate change, the Atmospheric Radiation Measurement (ARM) Program (www.arm.gov) is improving the treatment of cloud radiative forcing and feedbacks in general

  3. U.S. and Portugal Sign Agreement for Climate Research Collaboration |

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Department of Energy Portugal Sign Agreement for Climate Research Collaboration U.S. and Portugal Sign Agreement for Climate Research Collaboration March 27, 2009 - 12:00am Addthis WASHINGTON, DC - The United States signed an agreement with Portugal today to launch the installation of a portable climate observatory on Graciosa Island in the Azores. The mobile observatory will obtain measurements of cloud and aerosol properties from the island's marine environment for 20 months, beginning in

  4. First observations of tracking clouds using scanning ARM cloud...

    Office of Scientific and Technical Information (OSTI)

    These measurements complement cloud and precipitation tracking using geostationary satellites and weather radars. Here, two-dimensional (2-D) Along-Wind Range Height Indicator ...

  5. TURBULENCE DECAY AND CLOUD CORE RELAXATION IN MOLECULAR CLOUDS

    SciTech Connect (OSTI)

    Gao, Yang; Law, Chung K.; Xu, Haitao

    2015-02-01

    The turbulent motion within molecular clouds is a key factor controlling star formation. Turbulence supports molecular cloud cores from evolving to gravitational collapse and hence sets a lower bound on the size of molecular cloud cores in which star formation can occur. On the other hand, without a continuous external energy source maintaining the turbulence, such as in molecular clouds, the turbulence decays with an energy dissipation time comparable to the dynamic timescale of clouds, which could change the size limits obtained from Jean's criterion by assuming constant turbulence intensities. Here we adopt scaling relations of physical variables in decaying turbulence to analyze its specific effects on the formation of stars. We find that the decay of turbulence provides an additional approach for Jeans' criterion to be achieved, after which gravitational infall governs the motion of the cloud core. This epoch of turbulence decay is defined as cloud core relaxation. The existence of cloud core relaxation provides a more complete understanding of the effect of the competition between turbulence and gravity on the dynamics of molecular cloud cores and star formation.

  6. Global distribution and climate forcing of marine organic aerosol: 1. Model improvements and evaluation

    SciTech Connect (OSTI)

    Meskhidze, N.; Xu, J.; Gantt, Brett; Zhang, Yang; Nenes, Athanasios; Ghan, Steven J.; Liu, Xiaohong; Easter, Richard C.; Zaveri, Rahul A.

    2011-11-23

    Marine organic aerosol emissions have been implemented and evaluated within the National Center of Atmospheric Research (NCAR)'s Community Atmosphere Model (CAM5) with the Pacific Northwest National Laboratory's 7-mode Modal Aerosol Module (MAM-7). Emissions of marine primary organic aerosols (POA), phytoplanktonproduced isoprene- and monoterpenes-derived secondary organic aerosols (SOA) and methane sulfonate (MS{sup -}) are shown to affect surface concentrations of organic aerosols in remote marine regions. Global emissions of submicron marine POA is estimated to be 7.9 and 9.4 Tg yr{sup -1}, for the Gantt et al. (2011) and Vignati et al. (2010) emission parameterizations, respectively. Marine sources of SOA and particulate MS{sup -} (containing both sulfur and carbon atoms) contribute an additional 0.2 and 5.1 Tg yr{sup -1}, respectively. Widespread areas over productive waters of the Northern Atlantic, Northern Pacific, and the Southern Ocean show marine-source submicron organic aerosol surface concentrations of 100 ngm{sup -3}, with values up to 400 ngm{sup -3} over biologically productive areas. Comparison of long-term surface observations of water insoluble organic matter (WIOM) with POA concentrations from the two emission parameterizations shows that despite revealed discrepancies (often more than a factor of 2), both Gantt et al. (2011) and Vignati et al. (2010) formulations are able to capture the magnitude of marine organic aerosol concentrations, with the Gantt et al. (2011) parameterization attaining better seasonality. Model simulations show that the mixing state of the marine POA can impact the surface number concentration of cloud condensation nuclei (CCN). The largest increases (up to 20 %) in CCN (at a supersaturation (S) of 0.2 %) number concentration are obtained over biologically productive ocean waters when marine organic aerosol is assumed to be externally mixed with sea-salt. Assuming marine organics are internally-mixed with sea

  7. Atmospheric emitted radiance interferometer (AERI): Status and the aerosol explanation for extra window region emissions

    SciTech Connect (OSTI)

    Revercomb, H.E.; Knuteson, R.O.; Best, F.A.; Dirkx, T.P.

    1996-04-01

    High spectral resolution observations of downwelling emission from 3 to 19 microns have been made by the Atmospheric Emitted Radiance Interferometer (AERI) Prototype at the Southern Great Plains (SGP) Cloud and Radiative Testbed (CART) site for over two years. The spectral data set from AERI provides a basis for improving clear sky radiative transfer; determining the radiative impact of clouds, including the derivation of cloud radiative properties; defining the influences of aerosols in the window regions; and retrieving boundary layer state properties, including temperature, water vapor, and other trace gases. The data stream of radiometrically and spectrally calibrated radiances is routinely provided by Pacific Northwest Laboratory (PNL) to those science teams requesting it, and further information on the instrument and data characteristics is available in the ARM Science Team proceedings for 1993 and 1994 and in several conference publications. This paper describes the AERI status, calibration, field experiment wit a new AERI-01 and schedule, window region emissions, and future AERI plans.

  8. ARM: Tandem Differential Mobility Analyzer Aerosol Particle Sizer...

    Office of Scientific and Technical Information (OSTI)

    Subject: 54 Environmental Sciences Aerosol concentration; Aerosol particle size distribution; Hygroscopic growth; Particle number concentration; Particle size distribution Dataset ...

  9. Cumulus Clouds and Reflected Sunlight

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Cumulus Clouds and Reflected Sunlight from Landsat ETM+ G. Wen and L. Oreopoulos National Aeronautics and Space Administration Goddard Space Flight Center University of Maryland Baltimore County Joint Center of Earth System Technology Greenbelt, Maryland R. F. Cahalan and S. C. Tsay National Aeronautics and Space Administration Goddard Space Flight Center Greenbelt, Maryland Introduction Cumulus clouds attenuate solar radiation casting shows on the ground. Cumulus clouds can also enhance solar

  10. ARM - Measurement - Cloud ice particle

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    : Lear Jet PARTIMG : Particle imager UAV-PROTEUS-MICRO : Proteus Cloud Microphysics ... particle imager MET : Surface Meteorological Instrumentation UAV-PROTEUS : UAV Proteus

  11. ARM - Measurement - Cloud droplet size

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Impactor MIRAI : JAMSTEC Research Vessel Mirai PDI : Phase Doppler Interferometer UAV-PROTEUS-MICRO : Proteus Cloud Microphysics Instruments SPEC-CPI : Stratton Park ...

  12. ARM - Measurement - Cloud optical depth

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    TWST : Three Waveband Spectrally-agile Technique Sensor WRF-CHEM : Weather Research and Forecasting (WRF) Model Output Value-Added Products LBTM-MINNIS : Minnis Cloud Products...

  13. ARM - Measurement - Cloud top height

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    RUC : Rapid Update Cycle Model Data Field Campaign Instruments CO2LIDAR : Carbon Dioxide Doppler Lidar MPLCMASK : Cloud mask from Micropulse Lidar VARANAL : Constrained...

  14. Study of Aerosol Indirect Effects in China

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Aerosol Indirect Effects in China In 2008, the U.S. Department of Energy (DOE)'s ... of regional aerosol impacts in China as part of a joint program with the ...

  15. ARM - Evaluation Product - Aerosol Modeling Testbed

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    The Aerosol Modeling Testbed (AMT) is a means of organizing a wide range of measurements into a single data set that modelers can use to evaluate the performance of aerosol, ...

  16. The influence of mixed and phase clouds on surface shortwave irradiance during the Arctic spring

    SciTech Connect (OSTI)

    Lubin D.; Vogelmann A.

    2011-10-13

    The influence of mixed-phase stratiform clouds on the surface shortwave irradiance is examined using unique spectral shortwave irradiance measurements made during the Indirect and Semi-Direct Aerosol Campaign (ISDAC), supported by the U.S. Department of Energy Atmospheric Radiation Measurement (ARM) program. An Analytical Spectral Devices (ASD, Inc.) spectroradiometer measured downwelling spectral irradiance from 350 to 2200 nm in one-minute averages throughout April-May 2008 from the ARM Climate Research Facility's North Slope of Alaska (NSA) site at Barrow. This study examines spectral irradiance measurements made under single-layer, overcast cloud decks having geometric thickness < 3000 m. Cloud optical depth is retrieved from irradiance in the interval 1022-1033 nm. The contrasting surface radiative influences of mixed-phase clouds and liquid-water clouds are discerned using irradiances in the 1.6-{micro}m window. Compared with liquid-water clouds, mixed-phase clouds during the Arctic spring cause a greater reduction of shortwave irradiance at the surface. At fixed conservative-scattering optical depth (constant optical depth for wavelengths {lambda} < 1100 nm), the presence of ice water in cloud reduces the near-IR surface irradiance by an additional several watts-per-meter-squared. This additional reduction, or supplemental ice absorption, is typically {approx}5 W m{sup -2} near solar noon over Barrow, and decreases with increasing solar zenith angle. However, for some cloud decks this additional absorption can be as large as 8-10 W m{sup -2}.

  17. ARM - PI Product - Direct Aerosol Forcing Uncertainty

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ProductsDirect Aerosol Forcing Uncertainty ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send PI Product : Direct Aerosol Forcing Uncertainty Understanding sources of uncertainty in aerosol direct radiative forcing (DRF), the difference in a given radiative flux component with and without aerosol, is essential to quantifying changes in Earth's radiation budget. We examine the uncertainty in DRF due to measurement

  18. Aerosol Oxidation Speeds Up in Smoggy Air

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Aerosol Oxidation Speeds Up in Smoggy Air Aerosol Oxidation Speeds Up in Smoggy Air Print Wednesday, 17 February 2016 11:37 Organic aerosols (nanometer-sized liquid or solid particles suspended in air) are important constituents of the troposphere, and their chemistry has large-scale impacts on climate, pollution, and health. Accurate predictions of these aerosol impacts require a robust microphysical understanding of all relevant chemical reaction mechanisms and time scales, including those

  19. ARM - Measurement - Aerosol particle size distribution

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AOS : Aerosol Observing System CSPHOT : Cimel Sunphotometer HTDMA : Humidified Tandem Differential Mobility Analyzer SMPS : Scanning mobility particle sizer TDMA : Tandem...

  20. Widget:LogoCloud | Open Energy Information

    Open Energy Info (EERE)

    LogoCloud Jump to: navigation, search This widget adds css selectors and javascript for the Template:LogoCloud. For example: Widget:LogoCloud Retrieved from "http:...

  1. In-Situ Characterization of Cloud Condensation Nuclei, Interstitial, and background Particles using Single Particle Mass Spectrometer, SPLAT II

    SciTech Connect (OSTI)

    Zelenyuk, Alla; Imre, D.; Earle, Michael; Easter, Richard C.; Korolev, Alexei; Leaitch, W. R.; Liu, Peter; Macdonald, A. M.; Ovchinnikov, Mikhail; Strapp, Walter

    2010-10-01

    Aerosol indirect effect remains the most uncertain aspect of climate change modeling because proper test requires knowledge of individual particles sizes and compositions with high spatial and temporal resolution. We present the first deployment of a single particle mass spectrometer (SPLAT II) that is operated in a dual data acquisition mode to measure all the required individual particle properties with sufficient temporal resolution to definitively resolve the aerosol-cloud interaction in this exemplary case. We measured particle number concentrations, asphericity, and individual particle size, composition, and density with better than 60 seconds resolution. SPLAT II measured particle number concentrations between 70 particles cm-3and 300 particles cm-3, an average particle density of 1.4 g cm-3. Found that most particles are composed of oxygenated organics, many of which are mixed with sulfates. Biomass burn particles some with sulfates were prevalent, particularly at higher altitudes, and processed sea-salt was observed over the ocean. Analysis of cloud residuals shows that with time cloud droplets acquire sulfate by the reaction of peroxide with SO2. Based on the particle mass spectra and densities we find that the compositions of cloud condensation nuclei are similar to those of background aerosol but, contain on average ~7% more sulfate, and do not include dust and metallic particles. A comparison between the size distributions of background, activated, and interstitial particles shows that while nearly none of the activated particles is smaller than 115 nm, more than 80% of interstitial particles are smaller than 115 nm. We conclude that for this cloud the most important difference between CCN and background aerosol is particle size although having more sulfate also helps.

  2. The role of clouds and oceans in global greenhouse warming. Final report

    SciTech Connect (OSTI)

    Hoffert, M.I.

    1996-10-01

    This research focuses on assessing connections between anthropogenic greenhouse gas emissions and global climatic change. it has been supported since the early 1990s in part by the DOE ``Quantitative Links`` Program (QLP). A three-year effort was originally proposed to the QLP to investigate effects f global cloudiness on global climate and its implications for cloud feedback; and to continue the development and application of climate/ocean models, with emphasis on coupled effects of greenhouse warming and feedbacks by clouds and oceans. It is well-known that cloud and ocean processes are major sources of uncertainty in the ability to predict climatic change from humankind`s greenhouse gas and aerosol emissions. And it has always been the objective to develop timely and useful analytical tools for addressing real world policy issues stemming from anthropogenic climate change.

  3. Zenith Radiance Retrieval of Cloud Properties

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    retrievals of cloud properties from the AMF/COPS campaign Preliminary retrievals of cloud properties from the AMF/COPS campaign Christine Chiu, UMBC/JCET Alexander Marshak, GSFC Yuri Knyazikhin, Boston University Warren Wiscombe, GSFC Christine Chiu, UMBC/JCET Alexander Marshak, GSFC Yuri Knyazikhin, Boston University Warren Wiscombe, GSFC The cloud optical properties of interest are: The cloud optical properties of interest are: * Cloud optical depth τ - the great unknown * Radiative cloud

  4. Real time infrared aerosol analyzer

    DOE Patents [OSTI]

    Johnson, Stanley A.; Reedy, Gerald T.; Kumar, Romesh

    1990-01-01

    Apparatus for analyzing aerosols in essentially real time includes a virtual impactor which separates coarse particles from fine and ultrafine particles in an aerosol sample. The coarse and ultrafine particles are captured in PTFE filters, and the fine particles impact onto an internal light reflection element. The composition and quantity of the particles on the PTFE filter and on the internal reflection element are measured by alternately passing infrared light through the filter and the internal light reflection element, and analyzing the light through infrared spectrophotometry to identify the particles in the sample.

  5. [Multifractal cloud properties data assessment

    SciTech Connect (OSTI)

    Gautier, C.; Ricchiazzi, P.; Peterson, P.; Lavallee, D. ); Frouin, R.; Lubin, D. ); Lovejoy, S. ); Schertzer, D. )

    1992-05-06

    Our group has been very active over the last year, analyzing a number of data sets to characterize multifractal cloud properties and assess the effects of clouds on surface radiation properties (spectral and broadband). The data sets analyzed include: AVHRR observations of clouds over the ocean, SPOT observations of clouds over the ocean, SSM/I observations of clouds over the ocean, pyranometer data with all-sky photographs, pyrgeometer data all-sky photographs, and spectral surface irradiance all-sky photographs. A number of radiative transfer computations have been performed to help in the interpretation of these observations or provide theoretical guidance for their analysis. Finally 4 number of radiative transfer models have been acquired and tested to prepare for the interpretation of ARM/CART data.

  6. Satellite determination of stratus cloud microphysical properties...

    Office of Scientific and Technical Information (OSTI)

    of liquid water path from SSMI, broadband albedo from ERBE, and cloud characteristics from ISCCP are used to study stratus regions. An average cloud liquid water path of ...

  7. Clouds Environmental Ltd | Open Energy Information

    Open Energy Info (EERE)

    Clouds Environmental Ltd Jump to: navigation, search Name: Clouds Environmental Ltd Place: Portsmouth, United Kingdom Zip: PO3 5EG Product: Independent consultancy specialising in...

  8. Radiative Effects of Cloud Inhomogeneity and

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Ackerman et al. 1999), to develop cloud statistics and improve the treatment of subgrid ... and Curry 1989; Liang and Wang 1997). Statistics of Subgrid Cloud Variability We have ...

  9. Aerosol Behavior Log-Normal Distribution Model.

    Energy Science and Technology Software Center (OSTI)

    2001-10-22

    HAARM3, an acronym for Heterogeneous Aerosol Agglomeration Revised Model 3, is the third program in the HAARM series developed to predict the time-dependent behavior of radioactive aerosols under postulated LMFBR accident conditions. HAARM3 was developed to include mechanisms of aerosol growth and removal which had not been accounted for in the earlier models. In addition, experimental measurements obtained on sodium oxide aerosols have been incorporated in the code. As in HAARM2, containment gas temperature, pressure,more » and temperature gradients normal to interior surfaces are permitted to vary with time. The effects of reduced density on sodium oxide agglomerate behavior and of nonspherical shape of particles on aerosol behavior mechanisms are taken into account, and aerosol agglomeration due to turbulent air motion is considered. Also included is a capability to calculate aerosol concentration attenuation factors and to restart problems requiring long computing times.« less

  10. Pathways of sulfate enhancement by natural and anthropogenic mineral aerosols in China

    SciTech Connect (OSTI)

    Huang, Xin; Song, Yu; Zhao, Chun; Li, Mengmeng; Zhu, Tong; Zhang, Qiang; Zhang, Xiaoye

    2014-12-27

    China, the world’s largest consumer of coal, emits approximately 30 million tons of sulfur dioxide (SO₂) per year. SO₂ is subsequently oxidized to sulfate in the atmosphere. However, large gaps exist between model-predicted and measured sulfate levels in China. Long-term field observations and numerical simulations were integrated to investigate the effect of mineral aerosols on sulfate formation. We found that mineral aerosols contributed a nationwide average of approximately 22% to sulfate production in 2006. The increased sulfate concentration was approximately 2 μg m⁻³ in the entire China. In East China and the Sichuan Basin, the increments reached 6.3 μg m⁻³ and 7.3 μg m⁻³, respectively. Mineral aerosols led to faster SO₂ oxidation through three pathways. First, more SO₂ was dissolved as cloud water alkalinity increased due to water-soluble mineral cations. Sulfate production was then enhanced through the aqueous-phase oxidation of S(IV) (dissolved sulfur in oxidation state +4). The contribution to the national sulfate production was 5%. Second, sulfate was enhanced through S(IV) catalyzed oxidation by transition metals. The contribution to the annual sulfate production was 8%, with 19% during the winter that decreased to 2% during the summer. Third, SO₂ reacts on the surface of mineral aerosols to produce sulfate. The contribution to the national average sulfate concentration was 9% with 16% during the winter and a negligible effect during the summer. The inclusion of mineral aerosols does resolve model discrepancies with sulfate observations in China, especially during the winter. These three pathways, which are not fully considered in most current chemistry-climate models, will significantly impact assessments regarding the effects of aerosol on climate change in China.

  11. Aerosol climate effects and air quality impacts from 1980 to 2030

    SciTech Connect (OSTI)

    Menon, Surabi; Menon, Surabi; Unger, Nadine; Koch, Dorothy; Francis, Jennifer; Garrett, Tim; Sednev, Igor; Shindell, Drew; Streets, David

    2007-11-26

    We investigate aerosol effects on climate for 1980, 1995 (meant to reflect present-day) and 2030 using the NASA Goddard Institute for Space Studies climate model coupled to an on-line aerosol source and transport model with interactive oxidant and aerosol chemistry. Aerosols simulated include sulfates, organic matter (OM), black carbon (BC), sea-salt and dust and additionally, the amount of tropospheric ozone is calculated, allowing us to estimate both changes to air quality and climate for different time periods and emission amounts. We include both the direct aerosol effect and indirect aerosol effects for liquid-phase clouds. Future changes for the 2030 A1B scenario are examined, focusing on the Arctic and Asia, since changes are pronounced in these regions. Our results for the different time periods include both emission changes and physical climate changes. We find that the aerosol indirect effect (AIE) has a large impact on photochemical processing, decreasing ozone amount and ozone forcing, especially for the future (2030-1995). Ozone forcings increase from 0 to 0.12 Wm{sup -2} and the total aerosol forcing increases from -0.10 Wm{sup -2} to -0.94 Wm{sup -2} (AIE increases from -0.13 to -0.68 Wm{sup -2}) for 1995-1980 versus 2030-1995. Over the Arctic we find that compared to ozone and the direct aerosol effect, the AIE contributes the most to net radiative flux changes. The AIE, calculated for 1995-1980, is positive (1.0 Wm{sup -2}), but the magnitude decreases (-0.3Wm{sup -2}) considerably for the future scenario. Over Asia, we evaluate the role of biofuel and transportation-based emissions (for BC and OM) via a scenario (2030A) that includes a projected increase (factor of two) in biofuel and transport-based emissions for 2030 A1B over Asia. Projected changes from present-day due to the 2030A emissions versus 2030 A1B are a factor of 4 decrease in summertime precipitation in Asia. Our results are sensitive to emissions used. Uncertainty in present

  12. Final Scientific/Technical Report Grant title: Use of ARM Measurements of Spectral Zenith Radiance for Better Understanding of 3D Cloud-Radiation Processes and Aerosol-Cloud Interaction This is a collaborative project with the NASA GSFC project of Dr. A. Marshak and W. Wiscombe (PIs). This report covers BU activities from February 2011 to June 2011 and BU "no-cost extension" activities from June 2011 to June 2012. This report summarizes results that complement a final technical report submitted by the PIs in 2011.

    SciTech Connect (OSTI)

    Knyazikhin, Y

    2012-09-10

    Main results are summarized for work in these areas: spectrally-invariant approximation within atmospheric radiative transfer; spectral invariance of single scattering albedo for water droplets and ice crystals at weakly absorbing wavelengths; seasonal changes in leaf area of Amazon forests from leaf flushing and abscission; and Cloud droplet size and liquid water path retrievals from zenith radiance measurements.

  13. cloud | OpenEI Community

    Open Energy Info (EERE)

    - 13:42 How cleantech-as-a-service will drive renewable energy adoption 2015 adoption Big Data clean tech clean-tech cleantech cleantech forum cleantech-as-a-service cloud...

  14. Macrophysical Properties of Tropical Cirrus Clouds from the CALIPSO Satellite and from Ground-based Micropulse and Raman Lidars

    SciTech Connect (OSTI)

    Thorsen, Tyler J.; Fu, Qiang; Comstock, Jennifer M.; Sivaraman, Chitra; Vaughan, Mark A.; Winker, D.; Turner, David D.

    2013-08-27

    Lidar observations of cirrus cloud macrophysical properties over the U.S. Department of Energy Atmospheric Radiation Measurement (ARM) program Darwin, Australia site are compared from the Cloud-Aerosol Lidar and In- frared Pathfinder Satellite Observation (CALIPSO) satellite, the ground-based ARM micropulse lidar (MPL), and the ARM Raman lidar (RL). Comparisons are made using the subset of profiles where the lidar beam is not fully attenuated. Daytime measurements using the RL are shown to be relatively unaffected by the solar background and are therefore suited for checking the validity of diurnal cycles. RL and CALIPSO cloud fraction profiles show good agreement while the MPL detects significantly less cirrus, particularly during the daytime. Both MPL and CALIPSO observations show that cirrus clouds occur less frequently during the day than at night at all altitudes. In contrast, the RL diurnal cy- cle is significantly different than zero only below about 11 km; where it is the opposite sign (i.e. more clouds during the daytime). For cirrus geomet- rical thickness, the MPL and CALIPSO observations agree well and both datasets have signficantly thinner clouds during the daytime than the RL. From the examination of hourly MPL and RL cirrus cloud thickness and through the application of daytime detection limits to all CALIPSO data we find that the decreased MPL and CALIPSO cloud thickness during the daytime is very likely a result of increased daytime noise. This study highlights the vast im- provement the RL provides (compared to the MPL) in the ARM program's ability to observe tropical cirrus clouds as well as a valuable ground-based lidar dataset for the validation of CALIPSO observations and to help im- prove our understanding of tropical cirrus clouds.

  15. Millimeter Wave Cloud Radar (MMCR) Handbook

    SciTech Connect (OSTI)

    KB Widener; K Johnson

    2005-01-30

    The millimeter cloud radar (MMCR) systems probe the extent and composition of clouds at millimeter wavelengths. The MMCR is a zenith-pointing radar that operates at a frequency of 35 GHz. The main purpose of this radar is to determine cloud boundaries (e.g., cloud bottoms and tops). This radar will also report radar reflectivity (dBZ) of the atmosphere up to 20 km. The radar possesses a doppler capability that will allow the measurement of cloud constituent vertical velocities.

  16. AMF Deployment, Graciosa Island, Azores

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Graciosa Island Home Data Plots and Baseline Instruments Satellite Retrievals Experiment Planning CAP-MBL Proposal Abstract and Related Campaigns Science Questions Science Plan...

  17. A Case Study of Urbanization Impact on Summer Precipitation in the Greater Beijing Metropolitan Area. Urban Heat Island Versus Aerosol Effects

    SciTech Connect (OSTI)

    Zhong, Shi; Qian, Yun; Zhao, Chun; Leung, Lai-Yung R.; Yang, Xiuqun

    2015-10-23

    Convection-resolving ensemble simulations using the WRF-Chem model coupled with a single-layer Urban Canopy Model (UCM) are conducted to investigate the individual and combined impacts of land use and anthropogenic pollutant emissions from urbanization on a heavy rainfall event in the Greater Beijing Metropolitan Area (GBMA) in China. The simulation with the urbanization effect included generally captures the spatial pattern and temporal variation of the rainfall event. An improvement of precipitation is found in the experiment including aerosol effect on both clouds and radiation. The expanded urban land cover and increased aerosols have an opposite effect on precipitation processes, with the latter playing a more dominant role, leading to suppressed convection and rainfall over the upstream (northwest) area, and enhanced convection and more precipitation in the downstream (southeast) region of the GBMA. In addition, the influence of aerosol indirect effect is found to overwhelm that of direct effect on precipitation in this rainfall event. Increased aerosols induce more cloud droplets with smaller size, which favors evaporative cooling and reduce updrafts and suppress convection over the upstream (northwest) region in the early stage of the rainfall event. As the rainfall system propagates southeastward, more latent heat is released due to the freezing of larger number of smaller cloud drops that are lofted above the freezing level, which is responsible for the increased updraft strength and convective invigoration over the downstream (southeast) area.

  18. Mean-state acceleration of cloud-resolving models and large eddy simulations

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Jones, C. R.; Bretherton, C. S.; Pritchard, M. S.

    2015-10-29

    In this study, large eddy simulations and cloud-resolving models (CRMs) are routinely used to simulate boundary layer and deep convective cloud processes, aid in the development of moist physical parameterization for global models, study cloud-climate feedbacks and cloud-aerosol interaction, and as the heart of superparameterized climate models. These models are computationally demanding, placing practical constraints on their use in these applications, especially for long, climate-relevant simulations. In many situations, the horizontal-mean atmospheric structure evolves slowly compared to the turnover time of the most energetic turbulent eddies. We develop a simple scheme to reduce this time scale separation to accelerate themore » evolution of the mean state. Using this approach we are able to accelerate the model evolution by a factor of 2–16 or more in idealized stratocumulus, shallow and deep cumulus convection without substantial loss of accuracy in simulating mean cloud statistics and their sensitivity to climate change perturbations. As a culminating test, we apply this technique to accelerate the embedded CRMs in the Superparameterized Community Atmosphere Model by a factor of 2, thereby showing that the method is robust and stable to realistic perturbations across spatial and temporal scales typical in a GCM.« less

  19. Mean-state acceleration of cloud-resolving models and large eddy simulations

    SciTech Connect (OSTI)

    Jones, C. R.; Bretherton, C. S.; Pritchard, M. S.

    2015-10-29

    In this study, large eddy simulations and cloud-resolving models (CRMs) are routinely used to simulate boundary layer and deep convective cloud processes, aid in the development of moist physical parameterization for global models, study cloud-climate feedbacks and cloud-aerosol interaction, and as the heart of superparameterized climate models. These models are computationally demanding, placing practical constraints on their use in these applications, especially for long, climate-relevant simulations. In many situations, the horizontal-mean atmospheric structure evolves slowly compared to the turnover time of the most energetic turbulent eddies. We develop a simple scheme to reduce this time scale separation to accelerate the evolution of the mean state. Using this approach we are able to accelerate the model evolution by a factor of 2–16 or more in idealized stratocumulus, shallow and deep cumulus convection without substantial loss of accuracy in simulating mean cloud statistics and their sensitivity to climate change perturbations. As a culminating test, we apply this technique to accelerate the embedded CRMs in the Superparameterized Community Atmosphere Model by a factor of 2, thereby showing that the method is robust and stable to realistic perturbations across spatial and temporal scales typical in a GCM.

  20. ARM - Surface Aerosol Observing System

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    FacilitiesSurface Aerosol Observing System AMF Information Science Architecture Baseline Instruments AMF1 AMF2 AMF3 MAOS AMF Fact Sheet Images Contacts AMF Deployments McMurdo Station, Antarctica, 2015-2016 Pearl Harbor, Hawaii, to San Francisco, California, 2015 Hyytiälä, Finland, 2014 Manacapuru, Brazil, 2014 Oliktok Point, Alaska, 2013 Los Angeles, California, to Honolulu, Hawaii, 2012 Cape Cod, Massachusetts, 2012 Gan Island, Maldives, 2011 Ganges Valley, India, 2011 Steamboat Springs,

  1. Evaluation of high-level clouds in cloud resolving model simulations...

    Office of Scientific and Technical Information (OSTI)

    Evaluation of high-level clouds in cloud resolving model simulations with ARM and KWAJEX observations Citation Details In-Document Search Title: Evaluation of high-level clouds in ...

  2. Composition and Reactions of Atmospheric Aerosol Particles

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Composition and Reactions of Atmospheric Aerosol Particles Print Microscopic aerosol particles in the atmosphere contain carbonaceous components from mineral dust and combustion emissions released from around the world. How long these tiny particles remain in the atmosphere can have a huge impact on the global climate. Measurements based on high-resolution scanning transmission x-ray images obtained at the ALS have revealed chemical reactions on and in atmospheric aerosol particles that caused

  3. Composition and Reactions of Atmospheric Aerosol Particles

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Composition and Reactions of Atmospheric Aerosol Particles Print Microscopic aerosol particles in the atmosphere contain carbonaceous components from mineral dust and combustion emissions released from around the world. How long these tiny particles remain in the atmosphere can have a huge impact on the global climate. Measurements based on high-resolution scanning transmission x-ray images obtained at the ALS have revealed chemical reactions on and in atmospheric aerosol particles that caused

  4. Aerosol Oxidation Speeds Up in Smoggy Air

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Aerosol Oxidation Speeds Up in Smoggy Air Print Organic aerosols (nanometer-sized liquid or solid particles suspended in air) are important constituents of the troposphere, and their chemistry has large-scale impacts on climate, pollution, and health. Accurate predictions of these aerosol impacts require a robust microphysical understanding of all relevant chemical reaction mechanisms and time scales, including those involving highly reactive free-radical molecules. However, detailed modeling is

  5. Aerosol Oxidation Speeds Up in Smoggy Air

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Aerosol Oxidation Speeds Up in Smoggy Air Print Organic aerosols (nanometer-sized liquid or solid particles suspended in air) are important constituents of the troposphere, and their chemistry has large-scale impacts on climate, pollution, and health. Accurate predictions of these aerosol impacts require a robust microphysical understanding of all relevant chemical reaction mechanisms and time scales, including those involving highly reactive free-radical molecules. However, detailed modeling is

  6. Aerosol Oxidation Speeds Up in Smoggy Air

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Aerosol Oxidation Speeds Up in Smoggy Air Print Organic aerosols (nanometer-sized liquid or solid particles suspended in air) are important constituents of the troposphere, and their chemistry has large-scale impacts on climate, pollution, and health. Accurate predictions of these aerosol impacts require a robust microphysical understanding of all relevant chemical reaction mechanisms and time scales, including those involving highly reactive free-radical molecules. However, detailed modeling is

  7. Composition and Reactions of Atmospheric Aerosol Particles

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Composition and Reactions of Atmospheric Aerosol Particles Print Microscopic aerosol particles in the atmosphere contain carbonaceous components from mineral dust and combustion emissions released from around the world. How long these tiny particles remain in the atmosphere can have a huge impact on the global climate. Measurements based on high-resolution scanning transmission x-ray images obtained at the ALS have revealed chemical reactions on and in atmospheric aerosol particles that caused

  8. Composition and Reactions of Atmospheric Aerosol Particles

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Composition and Reactions of Atmospheric Aerosol Particles Print Microscopic aerosol particles in the atmosphere contain carbonaceous components from mineral dust and combustion emissions released from around the world. How long these tiny particles remain in the atmosphere can have a huge impact on the global climate. Measurements based on high-resolution scanning transmission x-ray images obtained at the ALS have revealed chemical reactions on and in atmospheric aerosol particles that caused

  9. Composition and Reactions of Atmospheric Aerosol Particles

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Composition and Reactions of Atmospheric Aerosol Particles Print Microscopic aerosol particles in the atmosphere contain carbonaceous components from mineral dust and combustion emissions released from around the world. How long these tiny particles remain in the atmosphere can have a huge impact on the global climate. Measurements based on high-resolution scanning transmission x-ray images obtained at the ALS have revealed chemical reactions on and in atmospheric aerosol particles that caused

  10. Composition and Reactions of Atmospheric Aerosol Particles

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Composition and Reactions of Atmospheric Aerosol Particles Composition and Reactions of Atmospheric Aerosol Particles Print Wednesday, 29 June 2005 00:00 Microscopic aerosol particles in the atmosphere contain carbonaceous components from mineral dust and combustion emissions released from around the world. How long these tiny particles remain in the atmosphere can have a huge impact on the global climate. Measurements based on high-resolution scanning transmission x-ray images obtained at the

  11. he Impact of Primary Marine Aerosol on Atmospheric Chemistry, Radiation and Climate: A CCSM Model Development Study

    SciTech Connect (OSTI)

    Keene, William C.; Long, Michael S.

    2013-05-20

    marine aerosol production on the microphysical properties of aerosol populations and clouds over the ocean and the corresponding direct and indirect effects on radiative transfer; (2) atmospheric burdens of reactive halogen species and their impacts on O3, NOx, OH, DMS, and particulate non-sea-salt SO42-; and (3) the global production and influences of marine-derived particulate organic carbon. The model reproduced major characteristics of the marine aerosol system and demonstrated the potential sensitivity of global, decadal-scale climate metrics to multiphase marine-derived components of Earth's troposphere. Due to the combined computational burden of the coupled system, the currently available computational resources were the limiting factor preventing the adequate statistical analysis of the overall impact that multiphase chemistry might have on climate-scale radiative transfer and climate.

  12. Final Report for “Simulating the Arctic Winter Longwave Indirect Effects. A New Parameterization for Frost Flower Aerosol Salt Emissions” (DESC0006679) for 9/15/2011 through 9/14/2015

    SciTech Connect (OSTI)

    Russell, Lynn M.; Somerville, Richard C.J.; Burrows, Susannah; Rasch, Phil

    2015-12-12

    Description of the Project: This project has improved the aerosol formulation in a global climate model by using innovative new field and laboratory observations to develop and implement a novel wind-driven sea ice aerosol flux parameterization. This work fills a critical gap in the understanding of clouds, aerosol, and radiation in polar regions by addressing one of the largest missing particle sources in aerosol-climate modeling. Recent measurements of Arctic organic and inorganic aerosol indicate that the largest source of natural aerosol during the Arctic winter is emitted from crystal structures, known as frost flowers, formed on a newly frozen sea ice surface [Shaw et al., 2010]. We have implemented the new parameterization in an updated climate model making it the first capable of investigating how polar natural aerosol-cloud indirect effects relate to this important and previously unrecognized sea ice source. The parameterization is constrained by Arctic ARM in situ cloud and radiation data. The modified climate model has been used to quantify the potential pan-Arctic radiative forcing and aerosol indirect effects due to this missing source. This research supported the work of one postdoc (Li Xu) for two years and contributed to the training and research of an undergraduate student. This research allowed us to establish a collaboration between SIO and PNNL in order to contribute the frost flower parameterization to the new ACME model. One peer-reviewed publications has already resulted from this work, and a manuscript for a second publication has been completed. Additional publications from the PNNL collaboration are expected to follow.

  13. Composition and Reactions of Atmospheric Aerosol Particles

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    refine the computer models used to predict climate change. Tiny Specks with Large Effects Most people equate aerosols with hairspray and household cleaning products, but a...

  14. Composition and Reactions of Atmospheric Aerosol Particles

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    results will help climate scientists refine the computer models used to predict climate change. Tiny Specks with Large Effects Most people equate aerosols with hairspray and...

  15. ARM: Ultrahigh Sensitivity Aerosol Spectrometer (Dataset) | Data...

    Office of Scientific and Technical Information (OSTI)

    Ultrahigh Sensitivity Aerosol Spectrometer Authors: Cynthia Salwen ; Derek Hageman ; Bill Behrens ; Scott Smith ; Janek Uin ; Janek Uin ; Cynthia Salwen ; Annette Koontz ; Annette ...

  16. ARM - Two-Column Aerosol Project (TCAP)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    science objectives, the Atmospheric Radiation Measurement (ARM) Climate Research Facility will deploy the ARM Mobile Facility and the Mobile Aerosol Observing System on Cape...

  17. Composition and Reactions of Atmospheric Aerosol Particles

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    high-resolution scanning transmission x-ray images obtained at the ALS have revealed chemical reactions on and in atmospheric aerosol particles that caused particle growth while...

  18. Laboratory Investigation of Contact Freezing and the Aerosol to Ice Crystal Transformation Process

    SciTech Connect (OSTI)

    Shaw, Raymond A.

    2014-10-28

    This project has been focused on the following objectives: 1. Investigations of the physical processes governing immersion versus contact nucleation, specifically surface-induced crystallization; 2. Development of a quadrupole particle trap with full thermodynamic control over the temperature range 0 to –40 °C and precisely controlled water vapor saturation ratios for continuous, single-particle measurement of the aerosol to ice crystal transformation process for realistic ice nuclei; 3. Understanding the role of ice nucleation in determining the microphysical properties of mixed-phase clouds, within a framework that allows bridging between laboratory and field measurements.

  19. Preliminary Studies on the Variational Assimilation of Cloud...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Studies on the Variational Assimilation of Cloud-Radiation Observations Using ARM ... A linearized cloud scheme and a radiation scheme including cloud effects have been ...

  20. A novel approach for introducing cloud spatial structure into...

    Office of Scientific and Technical Information (OSTI)

    A novel approach for introducing cloud spatial structure into cloud radiative transfer ... Sponsoring Org: USDOE Country of Publication: United Kingdom Language: English Word Cloud ...

  1. MAGIC Cloud Properties from Zenith Radiance Data Final Campaign...

    Office of Scientific and Technical Information (OSTI)

    Title: MAGIC Cloud Properties from Zenith Radiance Data Final Campaign Summary Cloud droplet size and optical depth are the most fundamental properties for understanding cloud ...

  2. Evaluation of Mixed-Phase Cloud Microphysics Parameterizations...

    Office of Scientific and Technical Information (OSTI)

    the partitioning of condensed water into liquid droplets and ice crystals in these Arctic clouds, which affect modeled cloud phase, cloud lifetime and radiative properties. ...

  3. ARM: 10-minute TEMPORARY Raman Lidar: aerosol extinction profiles...

    Office of Scientific and Technical Information (OSTI)

    extinction profiles and aerosol optical thickness, from first Ferrare algorithm Citation Details In-Document Search Title: ARM: 10-minute TEMPORARY Raman Lidar: aerosol extinction ...

  4. Aerosol Retrievals from ARM SGP MFRSR Data (Dataset) | Data Explorer

    Office of Scientific and Technical Information (OSTI)

    Aerosol Retrievals from ARM SGP MFRSR Data Title: Aerosol Retrievals from ARM SGP MFRSR Data The Multi-Filter Rotating Shadowband Radiometer (MFRSR) makes precise simultaneous ...

  5. Aerosol specification in single-column Community Atmosphere Model...

    Office of Scientific and Technical Information (OSTI)

    Aerosol specification in single-column Community Atmosphere Model version 5 Prev Next Title: Aerosol specification in single-column Community Atmosphere Model version 5 ...

  6. Organic and Elemental Carbon Aerosol Particulates at the Southern...

    Office of Scientific and Technical Information (OSTI)

    Elemental Carbon Aerosol Particulates at the Southern Great Plains Site Field Campaign Report Citation Details In-Document Search Title: Organic and Elemental Carbon Aerosol ...

  7. Aerosol Properties Downwind of Biomass Burns Field Campaign Report

    Office of Scientific and Technical Information (OSTI)

    Science Aerosol Properties Downwind of Biomass Burns Field Campaign Report PR Buseck ... DOESC-ARM-15-076 Aerosol Properties Downwind of Biomass Burns Field Campaign Report PR ...

  8. ARM - Field Campaign - Carbonaceous Aerosol and Radiation Effects...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Photo-Acoustic Aerosol Light Absorption and Scattering Campaign Links ARM Data Discovery Browse Data Related Campaigns Carbonaceous Aerosol and Radiative Effects Study (CARES) ...

  9. Long-term measurements of submicrometer aerosol chemistry at...

    Office of Scientific and Technical Information (OSTI)

    Long-term measurements of submicrometer aerosol chemistry at the Southern Great Plains (SGP) using an Aerosol Chemical Speciation Monitor (ACSM) Title: Long-term measurements of ...

  10. Aerosol composition, chemistry, and source characterization during the 2008 VOCALS Experiment

    SciTech Connect (OSTI)

    Lee, Y.; Springston, S.; Jayne, J.; Wang, J.; Senum, G.; Hubbe, J.; Alexander, L.; Brioude, J.; Spak, S.; Mena-Carrasco, M.; Kleinman, L.; Daum, P.

    2010-03-15

    Chemical composition of fine aerosol particles over the northern Chilean coastal waters was determined onboard the U.S. DOE G-1 aircraft during the VOCALS (VAMOS Ocean-Cloud-Atmosphere-Land Study) field campaign between October 16 and November 15, 2008. SO42-, NO3-, NH4+, and total organics (Org) were determined using an Aerodyne Aerosol Mass Spectrometer, and SO42-, NO3-, NH4+, Na+, Cl-, CH3SO3-, Mg2+, Ca2+, and K+ were determined using a particle-into-liquid sampler-ion chromatography technique. The results show the marine boundary layer (MBL) aerosol mass was dominated by non- sea-salt SO42- followed by Na+, Cl-, Org, NO3-, and NH4+, in decreasing importance; CH3SO3-, Ca2+, and K+ rarely exceeded their respective limits of detection. The SO42- aerosols were strongly acidic as the equivalent NH4+ to SO42- ratio was only {approx}0.25 on average. NaCl particles, presumably of sea-salt origin, showed chloride deficits but retained Cl- typically more than half the equivalency of Na+, and are externally mixed with the acidic sulfate aerosols. Nitrate was observed only on sea-salt particles, consistent with adsorption of HNO3 on sea-salt aerosols, responsible for the Cl- deficit. Dust particles appeared to play a minor role, judging from the small volume differences between that derived from the observed mass concentrations and that calculated based on particle size distributions. Because SO42- concentrations were substantial ({approx}0.5 - {approx}3 {micro}g/m3) with a strong gradient (highest near the shore), and the ocean-emitted dimethylsulfide and its unique oxidation product, CH3SO3-, were very low (i.e., {le} 40 parts per trillion and <0.05 {micro}g/m3, respectively), the observed SO42- aerosols are believed to be primarily of terrestrial origin. Back trajectory calculations indicate sulfur emissions from smelters and power plants along coastal regions of Peru and Chile are the main sources of these SO4- aerosols. However, compared to observations, model

  11. Characterization of aerosols produced by surgical procedures

    SciTech Connect (OSTI)

    Yeh, H.C.; Muggenburg, B.A.; Lundgren, D.L.; Guilmette, R.A.; Snipes, M.B.; Jones, R.K.; Turner, R.S.

    1994-07-01

    In many surgeries, especially orthopedic procedures, power tools such as saws and drills are used. These tools may produce aerosolized blood and other biological material from bone and soft tissues. Surgical lasers and electrocautery tools can also produce aerosols when tissues are vaporized and condensed. Studies have been reported in the literature concerning production of aerosols during surgery, and some of these aerosols may contain infectious material. Garden et al. (1988) reported the presence of papilloma virus DNA in the fumes produced from laser surgery, but the infectivity of the aerosol was not assessed. Moon and Nininger (1989) measured the size distribution and production rate of emissions from laser surgery and found that particles were generally less than 0.5 {mu}m diameter. More recently there has been concern expressed over the production of aerosolized blood during surgical procedures that require power tools. In an in vitro study, the production of an aerosol containing the human immunodeficiency virus (HIV) was reported when power tools were used to cut tissues with blood infected with HIV. Another study measured the size distribution of blood aerosols produced by surgical power tools and found blood-containing particles in a number of size ranges. Health care workers are anxious and concerned about whether surgically produced aerosols are inspirable and can contain viable pathogens such as HIV. Other pathogens such as hepatitis B virus (HBV) are also of concern. The Occupational Safety and Health funded a project at the National Institute for Inhalation Toxicology Research Institute to assess the extent of aerosolization of blood and other tissues during surgical procedures. This document reports details of the experimental and sampling approach, methods, analyses, and results on potential production of blood-associated aerosols from surgical procedures in the laboratory and in the hospital surgical suite.

  12. Technical Note: On the use of nudging for aerosol-climate model intercomparison studies

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Zhang, K.; Wan, H.; Liu, X.; Ghan, S. J.; Kooperman, G. J.; Ma, P.-L.; Rasch, P. J.

    2014-04-24

    Nudging is an assimilation technique widely used in the development and evaluation of climate models. Constraining the simulated wind and temperature fields using global weather reanalysis facilitates more straightforward comparison between simulation and observation, and reduces uncertainties associated with natural variabilities of the large-scale circulation. On the other hand, the forcing introduced by nudging can be strong enough to change the basic characteristics of the model climate. In the paper we show that for the Community Atmosphere Model version 5, due to the systematic temperature bias in the standard model and the sensitivity of simulated ice formation to anthropogenic aerosolmore » concentration, nudging towards reanalysis results in substantial reductions in the ice cloud amount and the impact of anthropogenic aerosols on longwave cloud forcing. In order to reduce discrepancies between the nudged and unconstrained simulations and meanwhile take the advantages of nudging, two alternative experimentation methods are evaluated. The first one constrains only the horizontal winds. The second method nudges both winds and temperature, but replaces the long-term climatology of the reanalysis by that of the model. Results show that both methods lead to substantially improved agreement with the free-running model in terms of the top-of-atmosphere radiation budget and cloud ice amount. The wind-only nudging is more convenient to apply, and provides higher correlations of the wind fields, geopotential height and specific humidity between simulation and reanalysis. This suggests nudging the horizontal winds but not temperature is a good strategy for the investigation of aerosol indirect effects through ice clouds, since it provides well-constrained meteorology without strongly perturbing the model's mean climate.« less

  13. Technical Note: On the Use of Nudging for Aerosol-Climate Model Intercomparison Studies

    SciTech Connect (OSTI)

    Zhang, Kai; Wan, Hui; Liu, Xiaohong; Ghan, Steven J.; Kooperman, G. J.; Ma, Po-Lun; Rasch, Philip J.; Neubauer, David; Lohmann, U.

    2014-08-26

    Nudging is an assimilation technique widely used in the development and evaluation of climate models. Con- straining the simulated wind and temperature fields using global weather reanalysis facilitates more straightforward comparison between simulation and observation, and reduces uncertainties associated with natural variabilities of the large-scale circulation. On the other hand, the artificial forcing introduced by nudging can be strong enough to change the basic characteristics of the model climate. In the paper we show that for the Community Atmosphere Model version 5, due to the systematic temperature bias in the standard model and the relatively strong sensitivity of homogeneous ice nucleation to aerosol concentration, nudging towards reanalysis results in substantial reductions in the ice cloud amount and the impact of anthropogenic aerosols on longwave cloud forcing. In order to reduce discrepancies between the nudged and unconstrained simulations and meanwhile take the advantages of nudging, two alternative experimentation methods are evaluated. The first one constrains only the horizontal winds. The second method nudges both winds and temperature, but replaces the long-term climatology of the reanalysis by that of the model. Results show that both methods lead to substantially improved agreement with the free-running model in terms of the top-of-atmosphere radiation budget and cloud ice amount. The wind-only nudging is more convenient to apply, and provides higher correlations of the wind fields, geopotential height and specific humidity between simulation and reanalysis. This suggests that nudging the horizontal winds but not temperature is a good strategy, especially for studies that involve both warm and cold clouds.

  14. Final Technical Report for Interagency Agreement No. DE-SC0005453 “Characterizing Aerosol Distributions, Types, and Optical and Microphysical Properties using the NASA Airborne High Spectral Resolution Lidar (HSRL) and the Research Scanning Polarimeter (RSP)”

    SciTech Connect (OSTI)

    Hostetler, Chris; Ferrare, Richard

    2015-01-13

    Measurements of the vertical profile of atmospheric aerosols and aerosol optical and microphysical characteristics are required to: 1) determine aerosol direct and indirect radiative forcing, 2) compute radiative flux and heating rate profiles, 3) assess model simulations of aerosol distributions and types, and 4) establish the ability of surface and space-based remote sensors to measure the indirect effect. Consequently the ASR program calls for a combination of remote sensing and in situ measurements to determine aerosol properties and aerosol influences on clouds and radiation. As part of our previous DOE ASP project, we deployed the NASA Langley airborne High Spectral Resolution Lidar (HSRL) on the NASA B200 King Air aircraft during major field experiments in 2006 (MILAGRO and MaxTEX), 2007 (CHAPS), 2009 (RACORO), and 2010 (CalNex and CARES). The HSRL provided measurements of aerosol extinction (532 nm), backscatter (532 and 1064 nm), and depolarization (532 and 1064 nm). These measurements were typically made in close temporal and spatial coincidence with measurements made from DOE-funded and other participating aircraft and ground sites. On the RACORO, CARES, and CalNEX missions, we also deployed the NASA Goddard Institute for Space Studies (GISS) Research Scanning Polarimeter (RSP). RSP provided intensity and degree of linear polarization over a broad spectral and angular range enabling column-average retrievals of aerosol optical and microphysical properties. Under this project, we analyzed observations and model results from RACORO, CARES, and CalNex and accomplished the following objectives. 1. Identified aerosol types, characterize the vertical distribution of the aerosol types, and partition aerosol optical depth by type, for CARES and CalNex using HSRL data as we have done for previous missions. 2. Investigated aerosol microphysical and macrophysical properties using the RSP. 3. Used the aerosol backscatter and extinction profiles measured by the HSRL

  15. AEROSOL PARTICLE COLLECTOR DESIGN STUDY

    SciTech Connect (OSTI)

    Lee, S; Richard Dimenna, R

    2007-09-27

    A computational evaluation of a particle collector design was performed to evaluate the behavior of aerosol particles in a fast flowing gas stream. The objective of the work was to improve the collection efficiency of the device while maintaining a minimum specified air throughput, nominal collector size, and minimal power requirements. The impact of a range of parameters was considered subject to constraints on gas flow rate, overall collector dimensions, and power limitations. Potential improvements were identified, some of which have already been implemented. Other more complex changes were identified and are described here for further consideration. In addition, fruitful areas for further study are proposed.

  16. Aerosol Effects on Cirrus through Ice Nucleation in the Community Atmosphere Model CAM5 with a Statistical Cirrus Scheme

    SciTech Connect (OSTI)

    Wang, Minghuai; Liu, Xiaohong; Zhang, Kai; Comstock, Jennifer M.

    2014-09-01

    A statistical cirrus cloud scheme that tracks ice saturation ratio in the clear-sky and cloudy portion of a grid box separately has been implemented into NCAR CAM5 to provide a consistent treatment of ice nucleation and cloud formation. Simulated ice supersaturation and ice crystal number concentrations strongly depend on the number concentrations of heterogeneous ice nuclei (IN), subgrid temperature formulas and the number concentration of sulfate particles participating in homogeneous freezing, while simulated ice water content is insensitive to these perturbations. 1% to 10% dust particles serving as heterogeneous IN is 20 found to produce ice supersaturaiton in better agreement with observations. Introducing a subgrid temperature perturbation based on long-term aircraft observations of meso-scale motion produces a better hemispheric contrast in ice supersaturation compared to observations. Heterogeneous IN from dust particles significantly alter the net radiative fluxes at the top of atmosphere (TOA) (-0.24 to -1.59 W m-2) with a significant clear-sky longwave component (0.01 to -0.55 W m-2). Different cirrus treatments significantly perturb the net TOA anthropogenic aerosol forcing from -1.21 W m-2 to -1.54 W m-2, with a standard deviation of 0.10 W m-2. Aerosol effects on cirrus clouds exert an even larger impact on the atmospheric component of the radiative fluxes (two or three times the changes in the TOA radiative fluxes) and therefore on the hydrology cycle through the fast atmosphere response. This points to the urgent need to quantify aerosol effects on cirrus clouds through ice nucleation and how these further affect the hydrological cycle.

  17. Researching Impact of Clouds on Solar Plants

    Office of Energy Efficiency and Renewable Energy (EERE)

    Sandia National Laboratories (SNL) researchers developed a new system to monitor how clouds affect large-scale solar photovoltaic (PV) power plants. By observing cloud shape, size and movement, the...

  18. ARM - Field Campaign - Fall 1997 Cloud IOP

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    The primary objective of the Cloud IOP was to generate a multi-platform data set that can ... Given the diversity of cloud types sampled during the IOP, the analysis of this data set ...

  19. Evaluating the MMF Using CloudSat

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    its cloud Evaluate the MMF and improve its cloud simulations simulations Borrowed from Dave Randall, CSU The big picture The big picture ... ... . . Data ARM A-Train, MISR etc. ...

  20. ARM - Measurement - Cloud particle size distribution

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    from you Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Cloud particle size distribution The number of cloud particles present in any given volume of air...

  1. ARM - Measurement - Cloud particle number concentration

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    from you Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Cloud particle number concentration The total number of cloud particles present in any given volume...

  2. Impact of heterogeneous ice nuclei on homogeneous freezing events in cirrus clouds

    SciTech Connect (OSTI)

    Spichtinger, Peter; Cziczo, Daniel J.

    2010-07-29

    The influence of initial heterogeneous nucleation on subsequent homogeneous nucleation events in cirrus clouds is investigated using a box model which includes the explicit impact of aerosols on the nucleation of ice crystals and sedimentation. Different effects are discussed, namely the impact of external mixtures of heterogeneous ice nuclei and the influence of size-dependent freezing thresholds. Several idealized experiments are carried out, which show that the treatment of external mixtures of ice nuclei can strongly change later homogeneous nucleation events (i.e., the ice crystal number densities) in different matters. The use of size-dependent freezing thresholds can also change the cloud prop erties when compared to more simple parameterizations. This size effect is most important for large IN concentrations. Based upon these findings, recommendations for future modeling and measurement efforts are presented.

  3. What Makes Clouds Form, Grow and Die?

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Makes Clouds Form, Grow and Die? What Makes Clouds Form, Grow and Die? Simulations Show Raindrops Physics May Affect Climate Model Accuracy February 19, 2015 thunderstorm Brazil shuttle NASA 1984 540 PNNL scientists used real-world observations to simulate how small clouds are likely to stay shallow, while larger clouds grow deeper because they mix with less dry air. Pictured are small and large thunderstorms growing over southern Brazil, taken from the space shuttle. Image: NASA Johnson Space

  4. ARM Data for Cloud Parameterization

    SciTech Connect (OSTI)

    Xu, Kuan-Man

    2006-10-02

    The PI's ARM investigation (DE-IA02-02ER633 18) developed a physically-based subgrid-scale saturation representation that fully considers the direct interactions of the parameterized subgrid-scale motions with subgrid-scale cloud microphysical and radiative processes. Major accomplishments under the support of that interagency agreement are summarized in this paper.

  5. Unlocking the Secrets of Clouds

    Broader source: Energy.gov [DOE]

    Clouds may look soft, fluffy and harmless to the untrained eye, but to an expert climate model scientist they represent great challenges. Fortunately the Atmospheric Radiation Measurement (ARM) Climate and Research Facility is kicking off a five-month study which should significantly clear the air.

  6. Effect of Terrestrial and Marine Organic Aerosol on Regional and Global Climate: Model Development, Application, and Verification with Satellite Data

    SciTech Connect (OSTI)

    Meskhidze, Nicholas; Zhang, Yang; Kamykowski, Daniel

    2012-03-28

    In this DOE project the improvements to parameterization of marine primary organic matter (POM) emissions, hygroscopic properties of marine POM, marine isoprene derived secondary organic aerosol (SOA) emissions, surfactant effects, new cloud droplet activation parameterization have been implemented into Community Atmosphere Model (CAM 5.0), with a seven mode aerosol module from the Pacific Northwest National Laboratory (PNNL)'s Modal Aerosol Model (MAM7). The effects of marine aerosols derived from sea spray and ocean emitted biogenic volatile organic compounds (BVOCs) on microphysical properties of clouds were explored by conducting 10 year CAM5.0-MAM7 model simulations at a grid resolution 1.9° by 2.5° with 30 vertical layers. Model-predicted relationship between ocean physical and biological systems and the abundance of CCN in remote marine atmosphere was compared to data from the A-Train satellites (MODIS, CALIPSO, AMSR-E). Model simulations show that on average, primary and secondary organic aerosol emissions from the ocean can yield up to 20% increase in Cloud Condensation Nuclei (CCN) at 0.2% Supersaturation, and up to 5% increases in droplet number concentration of global maritime shallow clouds. Marine organics were treated as internally or externally mixed with sea salt. Changes associated with cloud properties reduced (absolute value) the model-predicted short wave cloud forcing from -1.35 Wm-2 to -0.25 Wm-2. By using different emission scenarios, and droplet activation parameterizations, this study suggests that addition of marine primary aerosols and biologically generated reactive gases makes an important difference in radiative forcing assessments. All baseline and sensitivity simulations for 2001 and 2050 using global-through-urban WRF/Chem (GU-WRF) were completed. The main objective of these simulations was to evaluate the capability of GU-WRF for an accurate representation of the global atmosphere by exploring the most accurate configuration of

  7. Microphysical Effects Determine Macrophysical Response for Aerosol...

    Office of Scientific and Technical Information (OSTI)

    Deep convective clouds (DCCs) play a crucial role in the general circulation and energy ... Sponsoring Org: USDOE Country of Publication: United States Language: English Subject: ...

  8. ARM - Field Campaign - MASRAD - Aerosol Optical Properties

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    govCampaignsMASRAD - Aerosol Optical Properties Campaign Links AMF Point Reyes Website ARM Data Discovery Browse Data Related Campaigns MArine Stratus Radiation Aerosol and Drizzle (MASRAD) IOP 2005.03.14, Miller, AMF Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : MASRAD - Aerosol Optical Properties 2005.06.29 - 2005.08.30 Lead Scientist : Anthony Strawa For data sets, see below. Abstract Principal Investigators: J. Ogren, C.

  9. Two-Column Aerosol Project (TCAP): Ground-Based Radiation and...

    Office of Scientific and Technical Information (OSTI)

    ... Sponsoring Org: USDOE Office of Science (SC), Biological and Environmental Research (BER) ... Subject: 54 ENVIRONMENTAL SCIENCES aerosols, aerosol optical depth, direct aerosol ...

  10. Natural Radionuclides and Isotopic Signatures for Determining Carbonaceous Aerosol Sources, Aerosol Lifetimes, and Washout Processes

    SciTech Connect (OSTI)

    Gaffney, Jeffrey

    2012-12-12

    This is the final technical report. The project description is as follows: to determine the role of aerosol radiative forcing on climate, the processes that control their atmospheric concentrations must be understood, and aerosol sources need to be determined for mitigation. Measurements of naturally occurring radionuclides and stable isotopic signatures allow the sources, removal and transport processes, as well as atmospheric lifetimes of fine carbonaceous aerosols, to be evaluated.

  11. Aerosol optical depth derived from solar radiometry observations at northern mid-latitude sites

    SciTech Connect (OSTI)

    Laulainen, N.S.; Larson, N.R.; Michalsky, J.J.; Harrison, L.C.

    1994-01-01

    Routine, automated solar radiometry observations began with the development of the Mobile Automated Scanning Photometer (MASP) and its installation at the Rattlesnake Mountain Observatory (RMO). We have introduced a microprocessor controlled rotating shadowband radiometer (RSR), both the single detector and the multi-filter/detector (MFRSR) versions to replace the MASP. The operational mode of the RSRs is substantially different than the MASP or other traditional sun-tracking radiometers, because, by virtue of the automated rotating shadowband, the total and diffuse irradiance on a horizontal plane are measured and the direct-normal component deduced through computation from the total and diffuse components by the self-contained microprocessor. Because the three irradiance components are measured using the same detector for a given wavelength, the calibration coefficients are identical for each component, thus reducing errors when comparing them. The MFRSR is the primary radiometric instrument in the nine-station Quantitative Links Network (QLN) established in the eastern United States in late 1991. Data from this network are being used to investigate how cloud- and aerosol-induced radiative effects vary in time and with cloud structure and type over a mid-latitude continental region. This work supports the DOE Quantitative Links Program to quantify linkages between changes in atmospheric composition and climate forcing. In this paper we describe the setup of the QLN and present aerosol optical depth results from the on-going measurements at PNL/RMO, as well as preliminary results from the QLN. From the time-series of data at each site, we compare seasonal variability and geographical differences, as well as the effect of the perturbation to the stratosphere by Mt. Pinatubo. Analysis of the wavelength dependence of optical depth also provides information on the evolution and changes in the size distribution of the aerosols.

  12. ARM - Field Campaign - In-situ Aerosol Profiles (Cessna Aerosol Flights)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    govCampaignsIn-situ Aerosol Profiles (Cessna Aerosol Flights) ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : In-situ Aerosol Profiles (Cessna Aerosol Flights) 2000.03.01 - 2007.10.31 Lead Scientist : John Ogren Data Availability As of 2007-01, data prior to 2006-01 are now available through the regular ARM archive in datastreams: sgpiapC1.a1 sgpiapavgC1.a1 Current data continues to be delivered to the

  13. Quantifying Diurnal Cloud Radiative Effects by Cloud Type in the Tropical Western Pacific

    SciTech Connect (OSTI)

    Burleyson, Casey D.; Long, Charles N.; Comstock, Jennifer M.

    2015-06-01

    Cloud radiative effects are examined using long-term datasets collected at the three Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facilities in the tropical western Pacific. We quantify the surface radiation budget, cloud populations, and cloud radiative effects by partitioning the data by cloud type, time of day, and as a function of large scale modes of variability such as El Niño Southern Oscillation (ENSO) phase and wet/dry seasons at Darwin. The novel facet of our analysis is that we break aggregate cloud radiative effects down by cloud type across the diurnal cycle. The Nauru cloud populations and subsequently the surface radiation budget are strongly impacted by ENSO variability whereas the cloud populations over Manus only shift slightly in response to changes in ENSO phase. The Darwin site exhibits large seasonal monsoon related variations. We show that while deeper convective clouds have a strong conditional influence on the radiation reaching the surface, their limited frequency reduces their aggregate radiative impact. The largest source of shortwave cloud radiative effects at all three sites comes from low clouds. We use the observations to demonstrate that potential model biases in the amplitude of the diurnal cycle and mean cloud frequency would lead to larger errors in the surface energy budget compared to biases in the timing of the diurnal cycle of cloud frequency. Our results provide solid benchmarks to evaluate model simulations of cloud radiative effects in the tropics.

  14. Direct impact aerosol sampling by electrostatic precipitation

    DOE Patents [OSTI]

    Braden, Jason D.; Harter, Andrew G.; Stinson, Brad J.; Sullivan, Nicholas M.

    2016-02-02

    The present disclosure provides apparatuses for collecting aerosol samples by ionizing an air sample at different degrees. An air flow is generated through a cavity in which at least one corona wire is disposed and electrically charged to form a corona therearound. At least one grounded sample collection plate is provided downstream of the at least one corona wire so that aerosol ions generated within the corona are deposited on the at least one grounded sample collection plate. A plurality of aerosol samples ionized to different degrees can be generated. The at least one corona wire may be perpendicular to the direction of the flow, or may be parallel to the direction of the flow. The apparatus can include a serial connection of a plurality of stages such that each stage is capable of generating at least one aerosol sample, and the air flow passes through the plurality of stages serially.

  15. Long-Term Measurements of Submicrometer Aerosol

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    non-refractory submicron particulate matter (NR-PM1) including organic aerosol (OA), sulfate (SO 4 2- ), nitrate (NO 3 - ), ammonium (NH 4 + ), and chloride (Cl-). In this study,...

  16. ARM - Field Campaign - MASRAD: Marine Aerosol Properties

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    govCampaignsMASRAD: Marine Aerosol Properties Campaign Links AMF Point Reyes Website Comments? We would love to hear from you Send us a note below or call us at 1-888-ARM-DATA....

  17. Prediction of cloud condensation nuclei activity for organic compounds using functional group contribution methods

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Petters, M. D.; Kreidenweis, S. M.; Ziemann, P. J.

    2015-09-01

    A wealth of recent laboratory and field experiments demonstrate that organic aerosol composition evolves with time in the atmosphere, leading to changes in the influence of the organic fraction to cloud condensation nuclei (CCN) spectra. There is a need for tools that can realistically represent the evolution of CCN activity to better predict indirect effects of organic aerosol on clouds and climate. This work describes a model to predict the CCN activity of organic compounds from functional group composition. The model combines Khler theory with semi-empirical group contribution methods to estimate molar volumes, activity coefficients and liquid-liquid phase boundaries tomorepredict the effective hygroscopicity parameter, kappa. Model evaluation against a selected database of published laboratory measurements demonstrates that kappa can be predicted within a factor of two. Simulation of homologous series is used to identify the relative effectiveness of different functional groups in increasing the CCN activity of weakly functionalized organic compounds. Hydroxyl, carboxyl, aldehyde, hydroperoxide, carbonyl, and ether moieties promote CCN activity while methylene and nitrate moieties inhibit CCN activity. The model can be incorporated into scale-bridging testbeds such as the Generator of Explicit Chemistry and Kinetics of Organics in the Atmosphere to evaluate the evolution of kappa for a complex mix of organic compounds and to develop suitable parameterizations of CCN evolution for larger scale models.less

  18. Prediction of cloud condensation nuclei activity for organic compounds using functional group contribution methods

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Petters, M. D.; Kreidenweis, S. M.; Ziemann, P. J.

    2016-01-19

    A wealth of recent laboratory and field experiments demonstrate that organic aerosol composition evolves with time in the atmosphere, leading to changes in the influence of the organic fraction to cloud condensation nuclei (CCN) spectra. There is a need for tools that can realistically represent the evolution of CCN activity to better predict indirect effects of organic aerosol on clouds and climate. This work describes a model to predict the CCN activity of organic compounds from functional group composition. Following previous methods in the literature, we test the ability of semi-empirical group contribution methods in Köhler theory to predict themore » effective hygroscopicity parameter, kappa. However, in our approach we also account for liquid–liquid phase boundaries to simulate phase-limited activation behavior. Model evaluation against a selected database of published laboratory measurements demonstrates that kappa can be predicted within a factor of 2. Simulation of homologous series is used to identify the relative effectiveness of different functional groups in increasing the CCN activity of weakly functionalized organic compounds. Hydroxyl, carboxyl, aldehyde, hydroperoxide, carbonyl, and ether moieties promote CCN activity while methylene and nitrate moieties inhibit CCN activity. The model can be incorporated into scale-bridging test beds such as the Generator of Explicit Chemistry and Kinetics of Organics in the Atmosphere (GECKO-A) to evaluate the evolution of kappa for a complex mix of organic compounds and to develop suitable parameterizations of CCN evolution for larger-scale models.« less

  19. Prediction of cloud condensation nuclei activity for organic compounds using functional group contribution methods

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Petters, M. D.; Kreidenweis, S. M.; Ziemann, P. J.

    2016-01-19

    A wealth of recent laboratory and field experiments demonstrate that organic aerosol composition evolves with time in the atmosphere, leading to changes in the influence of the organic fraction to cloud condensation nuclei (CCN) spectra. There is a need for tools that can realistically represent the evolution of CCN activity to better predict indirect effects of organic aerosol on clouds and climate. This work describes a model to predict the CCN activity of organic compounds from functional group composition. Following previous methods in the literature, we test the ability of semi-empirical group contribution methods in Kohler theory to predict themore » effective hygroscopicity parameter, kappa. However, in our approach we also account for liquid–liquid phase boundaries to simulate phase-limited activation behavior. Model evaluation against a selected database of published laboratory measurements demonstrates that kappa can be predicted within a factor of 2. Simulation of homologous series is used to identify the relative effectiveness of different functional groups in increasing the CCN activity of weakly functionalized organic compounds. Hydroxyl, carboxyl, aldehyde, hydroperoxide, carbonyl, and ether moieties promote CCN activity while methylene and nitrate moieties inhibit CCN activity. Furthermore, the model can be incorporated into scale-bridging test beds such as the Generator of Explicit Chemistry and Kinetics of Organics in the Atmosphere (GECKO-A) to evaluate the evolution of kappa for a complex mix of organic compounds and to develop suitable parameterizations of CCN evolution for larger-scale models.« less

  20. Aerosol remote sensing in polar regions

    SciTech Connect (OSTI)

    Tomasi, Claudio; Kokhanovsky, Alexander A.; Lupi, Angelo; Ritter, Christoph; Smirnov, Alexander; O'Neill, Norman T.; Stone, Robert S.; Holben, Brent N.; Nyeki, Stephan; Mazzola, Mauro; Lanconelli, Christian; Vitale, Vito; Stebel, Kerstin; Aaltonen, Veijo; de Leeuw, Gerrit; Rodriguez, Edith; Herber, Andreas B.; Radionov, Vladimir F.; Zielinski, Tymon; Petelski, Tomasz; Sakerin, Sergey M.; Kabanov, Dmitry M.; Xue, Yong; Mei, Linlu; Istomina, Larysa; Wagener, Richard; McArthur, Bruce; Sobolewski, Piotr S.; Kivi, Rigel; Courcoux, Yann; Larouche, Pierre; Broccardo, Stephen; Piketh, Stuart J.

    2015-01-01

    Multi-year sets of ground-based sun-photometer measurements conducted at 12 Arctic sites and 9 Antarctic sites were examined to determine daily mean values of aerosol optical thickness ?(?) at visible and near-infrared wavelengths, from which best-fit values of ngstrm's exponent ? were calculated. Analysing these data, the monthly mean values of ?(0.50 ?m) and ? and the relative frequency histograms of the daily mean values of both parameters were determined for winterspring and summerautumn in the Arctic and for austral summer in Antarctica. The Arctic and Antarctic covariance plots of the seasonal median values of ? versus ?(0.50 ?m) showed: (i) a considerable increase in ?(0.50 ?m) for the Arctic aerosol from summer to winterspring, without marked changes in ?; and (ii) a marked increase in ?(0.50 ?m) passing from the Antarctic Plateau to coastal sites, whereas ? decreased considerably due to the larger fraction of sea-salt aerosol. Good agreement was found when comparing ground-based sun-photometer measurements of ?(?) and ? at Arctic and Antarctic coastal sites with Microtops measurements conducted during numerous AERONET/MAN cruises from 2006 to 2013 in three Arctic Ocean sectors and in coastal and off-shore regions of the Southern Atlantic, Pacific, and Indian Oceans, and the Antarctic Peninsula. Lidar measurements were also examined to characterise vertical profiles of the aerosol backscattering coefficient measured throughout the year at Ny-lesund. Satellite-based MODIS, MISR, and AATSR retrievals of ?(?) over large parts of the oceanic polar regions during spring and summer were in close agreement with ship-borne and coastal ground-based sun-photometer measurements. An overview of the chemical composition of mode particles is also presented, based on in-situ measurements at Arctic and Antarctic sites. Fourteen log-normal aerosol number size-distributions were defined to represent the average features of nuclei, accumulation and coarse mode particles

  1. Electrically Driven Technologies for Radioactive Aerosol Abatement

    SciTech Connect (OSTI)

    David W. DePaoli; Ofodike A. Ezekoye; Costas Tsouris; Valmor F. de Almeida

    2003-01-28

    The purpose of this research project was to develop an improved understanding of how electriexecy driven processes, including electrocoalescence, acoustic agglomeration, and electric filtration, may be employed to efficiently treat problems caused by the formation of aerosols during DOE waste treatment operations. The production of aerosols during treatment and retrieval operations in radioactive waste tanks and during thermal treatment operations such as calcination presents a significant problem of cost, worker exposure, potential for release, and increased waste volume.

  2. Apparatus for sampling and characterizing aerosols

    DOE Patents [OSTI]

    Dunn, P.F.; Herceg, J.E.; Klocksieben, R.H.

    1984-04-11

    Apparatus for sampling and characterizing aerosols having a wide particle size range at relatively low velocities may comprise a chamber having an inlet and an outlet, the chamber including: a plurality of vertically stacked, successive particle collection stages; each collection stage includes a separator plate and a channel guide mounted transverse to the separator plate, defining a labyrinthine flow path across the collection stage. An opening in each separator plate provides a path for the aerosols from one collection stage t

  3. Aerosol fabrication methods for monodisperse nanoparticles

    DOE Patents [OSTI]

    Jiang, Xingmao; Brinker, C Jeffrey

    2014-10-21

    Exemplary embodiments provide materials and methods for forming monodisperse particles. In one embodiment, the monodisperse particles can be formed by first spraying a nanoparticle-containing dispersion into aerosol droplets and then heating the aerosol droplets in the presence of a shell precursor to form core-shell particles. By removing either the shell layer or the nanoparticle core of the core-shell particles, monodisperse nanoparticles can be formed.

  4. Priorities for In-situ Aerosol Measurements

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Priorities for In-situ Aerosol Measurements Parameters * Aerosol light absorption coefficient - spectral, including UV, vis, and IR - as f(RH), and at ambient RH * Phase function - or relevant integral properties (how many?) * Ice nuclei * Scattering vs. RH, for RH>90% * CCN, as f(S, D p ) * Size distribution * Chemical composition - for determining climate forcing, vs. radiative effect Calibration * Number concentration * Size and shape * Light absorption reference method Characterization *

  5. WRF-Chem Simulations of Aerosols and Anthropogenic Aerosol Radiative Forcing in East Asia

    SciTech Connect (OSTI)

    Gao, Yi; Zhao, Chun; Liu, Xiaohong; Zhang, Meigen; Leung, Lai-Yung R.

    2014-08-01

    This study aims to provide a first comprehensive evaluation of WRF-Chem for modeling aerosols and anthropogenic aerosol radiative forcing (RF) over East Asia. Several numerical experiments were conducted from November 2007 to December 2008. Comparison between model results and observations shows that the model can generally reproduce the observed spatial distributions of aerosol concentration, aerosol optical depth (AOD) and single scattering albedo (SSA) from measurements at different sites, including the relatively higher aerosol concentration and AOD over East China and the relatively lower AOD over Southeast Asia, Korean, and Japan. The model also depicts the seasonal variation and transport of pollutions over East Asia. Particulate matter of 10 um or less in the aerodynamic diameter (PM10), black carbon (BC), sulfate (SO42-), nitrate (NO3-) and ammonium (NH4+) concentrations are higher in spring than other seasons in Japan due to the pollutant transport from polluted area of East Asia. AOD is high over Southwest and Central China in winter, spring and autumn and over North China in summer while is low over South China in summer due to monsoon precipitation. SSA is lowest in winter and highest in summer. The model also captures the dust events at the Zhangye site in the semi-arid region of China. Anthropogenic aerosol RF is estimated to range from -5 to -20 W m-2 over land and -20 to -40 W m-2 over ocean at the top of atmosphere (TOA), 5 to 30 W m-2 in the atmosphere (ATM) and -15 to -40 W m-2 at the bottom (BOT). The warming effect of anthropogenic aerosol in ATM results from BC aerosol while the negative aerosol RF at TOA is caused by scattering aerosols such as SO4 2-, NO3 - and NH4+. Positive BC RF at TOA compensates 40~50% of the TOA cooling associated with anthropogenic aerosol.

  6. The First Aerosol Indirect Effect: Beyond Twomey

    SciTech Connect (OSTI)

    Liu, Y.; Dunn, M.; Daum, P.

    2008-03-10

    The traditional first aerosol indirect effect or the Twomey effect involves several fundamental assumptions. Some of the assumptions (e.g., constant liquid water content) are explicitly stated in studies of the Twomey effect whereas others are only implicitly embedded in the quantitative formulation. This work focuses on examining the implicit assumptions. In particular, we will show that anthropogenic pollution not only increases aerosol loading and droplet concentrations but also alters the relative dispersions of both the aerosol and subsequent droplet size distributions. The indirect effects resulting from the two altered relative dispersions (aerosol dispersion effect and droplet dispersion effect) are likely opposite in sign and proportional in magnitude to the conventional Twomey effect. This result suggests that the outstanding problems of the Twomey effect (i.e., large uncertainty and overestimation reported in literature) may lie with violation of the constant spectral shapes of aerosol and droplet size distributions implicitly assumed in evaluation of the Twomey effect, and therefore, further progress in understanding and quantification of the first aerosol indirect effect demands moving beyond the traditional paradigm originally conceived by Twomey.

  7. DOE-SC-ARM-16-012 ARM Cloud-Aerosol-Precipitation Experiment...

    Office of Scientific and Technical Information (OSTI)

    ... Atmospheric Chemistry and Physics 14: 81-101, doi: 10.5194acp-14-81-2014. Givati, A, and D Rosenfeld. 2004. "Quantifying precipitation suppression due to air pollution." Journal ...

  8. DOE/SC-ARM-14-030 ARM Cloud Aerosol Precipitation Experiment

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ... in that region during winter, much of the rest of the orographic precipitation occurs in ... western U.S. during winter, much of the rest of the orographic precipitation occurs in ...

  9. Global and regional modeling of clouds and aerosols in the marine...

    Office of Scientific and Technical Information (OSTI)

    A diverse collection of models are used to simulate the marine boundary layer in the southeast Pacific region during the period of the October-November 2008 VOCALS REx (VAMOS Ocean ...

  10. Ground-based remote sensing scheme for monitoring aerosol-cloud...

    Office of Scientific and Technical Information (OSTI)

    Publisher: European Geosciences Union Research Org: Delft Univ. of Technology, Stevinweg, Delft (Netherlands) Sponsoring Org: USDOE Country of Publication: United States Language: ...

  11. Evaluation of Cloud Type Occurrences and Radiative Forcings Simulated by a Cloud Resolving Model Using Observations from Sa...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Cloud Type Occurrences and Radiative Forcings Simulated by a Cloud Resolving Model Using Observations from Satellite and Cloud Radar Y. Luo and S. K. Krueger University of Utah Salt Lake City, Utah Introduction Because of both the various effects clouds exert on the earth-atmospheric system and the cloud feedback, correct representations of clouds in numerical models are critical for accurate climate modeling and weather forecast. Unfortunately, determination of clouds and their radiative

  12. Failure and Redemption of Multifilter Rotating Shadowband Radiometer (MFRSR)/Normal Incidence Multifilter Radiometer (NIMFR) Cloud Screening: Contrasting Algorithm Performance at Atmospheric Radiation Measurement (ARM) North Slope of Alaska (NSA) and Southern Great Plains (SGP) Sites

    SciTech Connect (OSTI)

    Kassianov, Evgueni I.; Flynn, Connor J.; Koontz, Annette S.; Sivaraman, Chitra; Barnard, James C.

    2013-09-11

    Well-known cloud-screening algorithms, which are designed to remove cloud-contaminated aerosol optical depths (AOD) from AOD measurements, have shown great performance at many middle-to-low latitude sites around the world. However, they may occasionally fail under challenging observational conditions, such as when the sun is low (near the horizon) or when optically thin clouds with small spatial inhomogeneity occur. Such conditions have been observed quite frequently at the high-latitude Atmospheric Radiation Measurement (ARM) North Slope of Alaska (NSA) sites. A slightly modified cloud-screening version of the standard algorithm is proposed here with a focus on the ARM-supported Multifilter Rotating Shadowband Radiometer (MFRSR) and Normal Incidence Multifilter Radiometer (NIMFR) data. The modified version uses approximately the same techniques as the standard algorithm, but it additionally examines the magnitude of the slant-path line of sight transmittance and eliminates points when the observed magnitude is below a specified threshold. Substantial improvement of the multi-year (1999-2012) aerosol product (AOD and its Angstrom exponent) is shown for the NSA sites when the modified version is applied. Moreover, this version reproduces the AOD product at the ARM Southern Great Plains (SGP) site, which was originally generated by the standard cloud-screening algorithms. The proposed minor modification is easy to implement and its application to existing and future cloud-screening algorithms can be particularly beneficial for challenging observational conditions.

  13. Aerosol Characterization Data from the Asian Pacific Regional Aerosol Characterization Project (ACE-Asia)

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    The Aerosol Characterization Experiments (ACE) were designed to increase understanding of how atmospheric aerosol particles affect the Earth's climate system. These experiments integrated in-situ measurements, satellite observations, and models to reduce the uncertainty in calculations of the climate forcing due to aerosol particles and improve the ability of models to predict the influences of aerosols on the Earth's radiation balance. ACE-Asia was the fourth in a series of experiments organized by the International Global Atmospheric Chemistry (IGAC) Program (A Core Project of the International Geosphere Biosphere Program). The Intensive Field Phase for ACE-Asia took place during the spring of 2001 (mid-March through early May) off the coast of China, Japan and Korea. ACE-Asia pursued three specific objectives: 1) Determine the physical, chemical, and radiative properties of the major aerosol types in the Eastern Asia and Northwest Pacific region and investigate the relationships among these properties. 2) Quantify the physical and chemical processes controlling the evolution of the major aerosol types and in particular their physical, chemical, and radiative properties. 3) Develop procedures to extrapolate aerosol properties and processes from local to regional and global scales, and assess the regional direct and indirect radiative forcing by aerosols in the Eastern Asia and Northwest Pacific region [Edited and shortened version of summary at http://data.eol.ucar.edu/codiac/projs?ACE-ASIA]. The Ace-Asia collection contains 174 datasets.

  14. Testing a New Cirrus Cloud Parameterizaton

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Testing a New Cirrus Cloud Parameterization in NCAR CCM3 D. Zurovac-Jevtic, G. J. Zhang, and V. Ramanathan Center for Atmospheric Sciences Scripps Institute of Oceanography La Jolla, California Introduction Cirrus cloud cover and ice water content (IWC) are the two most important properties of cirrus clouds. However, in general circulation models (GCMs), their treatment is very crude. For example, in the National Center for Atmospheric Research (NCAR) Community Climate Model (CCM3), IWC is

  15. Midlatitude Continental Convective Clouds Experiment Science Objective

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Midlatitude Continental Convective Clouds Experiment Science Objective Despite improvements in computing power, current weather and climate models are unable to accurately reproduce the formation, growth, and decay of clouds and precipitation associated with storm systems. Not only is this due to a lack of data about precipitation, but also about the 3-dimensional environment of the surrounding clouds, winds, and moisture, and how that affects the transfer of energy between the sun and Earth. To

  16. Parameterizing correlations between hydrometeor species in mixed-phase Arctic clouds

    SciTech Connect (OSTI)

    Larson, Vincent E.; Nielsen, Brandon J.; Fan, Jiwen; Ovchinnikov, Mikhail

    2011-08-16

    Mixed-phase Arctic clouds, like other clouds, contain small-scale variability in hydrometeor fields, such as cloud water or snow mixing ratio. This variability may be worth parameterizing in coarse-resolution numerical models. In particular, for modeling processes such as accretion and aggregation, it would be useful to parameterize subgrid correlations among hydrometeor species. However, one difficulty is that there exist many hydrometeor species and many microphysical processes, leading to complexity and computational expense.Existing lower and upper bounds (inequalities) on linear correlation coefficients provide useful guidance, but these bounds are too loose to serve directly as a method to predict subgrid correlations. Therefore, this paper proposes an alternative method that is based on a blend of theory and empiricism. The method begins with the spherical parameterization framework of Pinheiro and Bates (1996), which expresses the correlation matrix in terms of its Cholesky factorization. The values of the elements of the Cholesky matrix are parameterized here using a cosine row-wise formula that is inspired by the aforementioned bounds on correlations. The method has three advantages: 1) the computational expense is tolerable; 2) the correlations are, by construction, guaranteed to be consistent with each other; and 3) the methodology is fairly general and hence may be applicable to other problems. The method is tested non-interactively using simulations of three Arctic mixed-phase cloud cases from two different field experiments: the Indirect and Semi-Direct Aerosol Campaign (ISDAC) and the Mixed-Phase Arctic Cloud Experiment (M-PACE). Benchmark simulations are performed using a large-eddy simulation (LES) model that includes a bin microphysical scheme. The correlations estimated by the new method satisfactorily approximate the correlations produced by the LES.

  17. Note: Design and development of wireless controlled aerosol sampling network for large scale aerosol dispersion experiments

    SciTech Connect (OSTI)

    Gopalakrishnan, V.; Subramanian, V.; Baskaran, R.; Venkatraman, B.

    2015-07-15

    Wireless based custom built aerosol sampling network is designed, developed, and implemented for environmental aerosol sampling. These aerosol sampling systems are used in field measurement campaign, in which sodium aerosol dispersion experiments have been conducted as a part of environmental impact studies related to sodium cooled fast reactor. The sampling network contains 40 aerosol sampling units and each contains custom built sampling head and the wireless control networking designed with Programmable System on Chip (PSoC™) and Xbee Pro RF modules. The base station control is designed using graphical programming language LabView. The sampling network is programmed to operate in a preset time and the running status of the samplers in the network is visualized from the base station. The system is developed in such a way that it can be used for any other environment sampling system deployed in wide area and uneven terrain where manual operation is difficult due to the requirement of simultaneous operation and status logging.

  18. Search for: All records | Data Explorer

    Office of Scientific and Technical Information (OSTI)

    site will have significant enhancements to instruments previously deployed to the Azores, including a Ka-W-band scanning cloud radar, precipitation radar, and Doppler lidar. ...

  19. Search for: All records | Data Explorer

    Office of Scientific and Technical Information (OSTI)

    Have feedback or suggestions for a way to improve these results? Cloud Property Retrieval Products for Graciosa Island, Azores Dong, Xiquan The motivation for developing this ...

  20. ARM - Datastreams - tsimovie

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    are those considered scientifically relevant. Measurement Variable Cloud fraction mpg Locations Eastern North Atlantic ENA C1 Browse Data Graciosa Island, Azores, Portugal...