Powered by Deep Web Technologies
Note: This page contains sample records for the topic "aerosol observing systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


1

ARM - Mobile Aerosol Observing System  

NLE Websites -- All DOE Office Websites (Extended Search)

FacilitiesMobile Aerosol Observing System FacilitiesMobile Aerosol Observing System AMF Information Science Architecture Baseline Instruments AMF1 AMF2 AMF3 Data Operations AMF Fact Sheet Images Contacts AMF Deployments 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, Colorado, 2010 Graciosa Island, Azores, 2009-2010 Shouxian, China, 2008 Black Forest, Germany, 2007 Niamey, Niger, 2006 Point Reyes, California, 2005 Mobile Aerosol Observing System Intensive aerosol observations conducted on the campus of Brookhaven National Laboratory on Long Island, New York, using the ARM Mobile Aerosol Observing System. Intensive aerosol observations conducted on the campus of Brookhaven

2

Aerosol Observing System (AOS) Handbook  

Science Conference Proceedings (OSTI)

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.

Jefferson, A

2011-01-17T23:59:59.000Z

3

ARM - Surface Aerosol Observing System  

NLE Websites -- All DOE Office Websites (Extended Search)

FacilitiesSurface Aerosol Observing System FacilitiesSurface Aerosol Observing System AMF Information Science Architecture Baseline Instruments AMF1 AMF2 AMF3 Data Operations AMF Fact Sheet Images Contacts AMF Deployments 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, Colorado, 2010 Graciosa Island, Azores, 2009-2010 Shouxian, China, 2008 Black Forest, Germany, 2007 Niamey, Niger, 2006 Point Reyes, California, 2005 Surface Aerosol Observing System The ARM Mobile Facility (AMF) is equipped to quantify the interaction between clouds and aerosol particles. A counter-flow virtual impactor (CVI) is used to selectively sample cloud drops. The CVI takes advantage of the

4

BNL | Mobile Aerosol Observing System (MAOS)  

NLE Websites -- All DOE Office Websites (Extended Search)

Mobile Aerosol Observing System (MAOS) Mobile Aerosol Observing System (MAOS) The Mobile Aerosol Observing System (MAOS) is a platform and instrument suite for Intensive Operation Periods (IOPs) to conduct in situ measurements of aerosols and their precursors. MAOS is part of the ARM Climate Research Facility. Physically MAOS is contained in two 20' SeaTainers custom adapted to provide a sheltered laboratory environment for operators and instruments even under harsh conditions. The two structures are designated MAOS-A and MAOS-C for Aerosol and Chemistry respectively. Although independent, with separate data systems, inlets and power distribution, the two structures are normally a single operating unit. The two enclosures comprising MAOS are designed for rapid deployment. All components (except for the Radar Wind Profiler) are transported internally

5

ARM's Aerosol Observing System (AOS) Data  

DOE Data Explorer (OSTI)

The aerosol observing system (AOS) is the primary Atmospheric Radiation Measurement (ARM) platform for in situ aerosol measurements at the surface. The principal measurements are those of the aerosol absorption and scattering coefficients as a function of the particle size and radiation wavelength. Additional measurements include those of the particle number concentration, size distribution, hygroscopic growth, and inorganic chemical composition. The AOS measures aerosol optical properties to better understand how particles interact with solar radiation and influence the earth's radiation balance. The 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. [Copied from http://www.arm.gov/instruments/aos]

The ARM Archive at Oak Ridge National Laboratory holds aerosol data from the AOS for two of the permanent ARM sites, North Slope Alaska (NSA) and Southern Great Plains (SGP), as well as from mobile facilities used during specific field campaigns. The AOS has collected data since 1995.

6

Aerosol observing system platform integration and AAF instrumentation  

SciTech Connect

As part of the federal governments 2009 American Recovery and Reinvestment Act (ARRA), the U.S. DOE Office of Science allocated funds for the capital upgrade of the Atmospheric Radiation Measurement (ARM) Climate Research Facility to improve and expand observational capabilities related to cloud and aerosol properties. The ARM Facility was established as a national user facility for the global scientific community to conduct a wide range of interdisciplinary science. Part of the ARRA-funded expansion of the ARM Facility includes four new Aerosol Observing Systems (AOS) to be designed, instrumented, and mentored by BNL. The enclosures will be customized SeaTainers. These new platforms ([AMF2]: ARM Mobile Facility-2; [TWP-D]: Tropical Western Pacific at Darwin; and [MAOS-A]/[MAOS-C]: Mobile Aerosol Observing System-Aerosol/-Chemistry) will provide a laboratory environment for fielding instruments to collect data on aerosol life cycle, microphysics, and optical/physical properties. The extensive instrument suite includes both established methods and initial deployments of new techniques to add breadth and depth to the AOS data sets. The platforms are designed: (1) to have all instruments pre-installed before deployment, allowing a higher measurement duty cycle; (2) with a standardized configuration improving the robustness of data inter-comparability; (3) to provide remote access capability for instrument mentors; and (4) to readily accommodate guest instrumentation. The first deployment of the AMF2 platform will be at the upcoming StormVEx campaign held at Steamboat Springs, Colorado, October 15, 2010March 31, 2011 while the TWP-D AOS will be stationed at the ARM Darwin site. The maiden deployments of the MAOS-A and MAOS-C platforms will be during the Ganges Valley Experiment (GVAX) scheduled for April 2011April 2012. In addition to the ground-based AOS platforms, thee major instrument builds for the AAF are also being undertaken (new trace gas package [NO, NOx, NOy, CO, O3, and SO2]; Scanning Mobility Particle Sampler [SMPS]; and Particle into Liquid Sampler [PILS]). The current status of the AOS platforms, instrument suites, instituted QA/QC activities, projected AOS VAPs, and inlet design, as well as still-unresolved issues, will be presented.

Springston, S.; Sedlacek, A.

2010-03-15T23:59:59.000Z

7

EMSL: Science: Atmospheric Aerosol Systems  

NLE Websites -- All DOE Office Websites (Extended Search)

Atmospheric Aerosol Systems Atmospheric Aerosol Systems atmospheric logo Nighttime enhancement of nitrogen-containing organic compounds, or NOC Observed nighttime enhancement of nitrogen-containing organic compounds, or NOC, showed evidence of being formed by reactions that transform carbonyls into imines. The Atmospheric Aerosol Systems Science Theme focuses on understanding the chemistry, physics and molecular-scale dynamics of aerosols for model parameterization to improve the accuracy of climate model simulations and develop a predictive understanding of climate. By elucidating the role of natural and anthropogenic regional and global climate forcing mechanisms, EMSL can provide DOE and others with the ability to develop cost-effective strategies to monitor, control and mitigate them.

8

Global observations of desert dust and biomass burning aerosols  

E-Print Network (OSTI)

Global observations of desert dust and biomass burning aerosols Martin de Graaf KNMI #12; Outline · Absorbing Aerosol Index - Theory · Absorbing Aerosol Index - Reality · Biomass burning.6 Biomass burning over Angola, 09 Sep. 2004 Absorbing Aerosol Index PMD image #12;biomass burning ocean

Graaf, Martin de

9

ARM - Measurement - Aerosol scattering  

NLE Websites -- All DOE Office Websites (Extended Search)

Spectrometer RL : Raman Lidar Field Campaign Instruments AOS : Aerosol Observing System DRI-GND : Desert Research Institute Ground-Based Aerosol Instruments AEROSOL-TOWER-EML :...

10

Aerosol Retrieval Using Remote-sensed Observations  

E-Print Network (OSTI)

electromagnetic solar radiation. The amount of atmosphericas the amount of solar radiation that aerosols scatter andbased on reflected solar radiation field measurements

Wang, Yueqing

2012-01-01T23:59:59.000Z

11

Micro Aerosol-based Decontamination System - Available ...  

Search PNNL. PNNL Home; About; Research; Publications; Jobs; News; Contacts; Micro Aerosol-based Decontamination System. Battelle Number(s): 15847. ...

12

Droplet activation properties of organic aerosols observed at...  

NLE Websites -- All DOE Office Websites (Extended Search)

activation properties of organic aerosols observed at an urban site during CalNex-LA Fan Mei, 1,7 Patrick L. Hayes, 2,3 Amber Ortega, 2,3 Jonathan W. Taylor, 4 James D. Allan,...

13

An Aerosol Climatology at Kyoto: Observed Local Radiative Forcing and Columnar Optical Properties  

Science Conference Proceedings (OSTI)

In order to evaluate the radiative effect of the atmospheric aerosol at Kyoto, Japan, surface solar irradiance and columnar aerosol optical properties were observed in the period between September 1998 and December 2001. The aerosol optical ...

Takahiro Yabe; Robert Hller; Susumu Tohno; Mikio Kasahara

2003-06-01T23:59:59.000Z

14

Lidar Observations of the Vertical Aerosol Flux in the Planetary Boundary Layer  

Science Conference Proceedings (OSTI)

The vertical aerosol transport in the planetary boundary layer (PBL) is investigated with lidars. Profiles of the vertical wind velocity are measured with a 2-?m Doppler wind lidar. Aerosol parameters are derived from observations with an aerosol ...

Ronny Engelmann; Ulla Wandinger; Albert Ansmann; Detlef Mller; Egidijus eromskis; Dietrich Althausen; Birgit Wehner

2008-08-01T23:59:59.000Z

15

Observations of Saharan Aerosols: Results of ECLATS Field Experiment. Part I: Optical Thicknesses and Aerosol Size Distributions  

Science Conference Proceedings (OSTI)

A series of ground-based and airborne observations of desert aerosols, the ECLATS experiment was carried out in December 1980 in the vicinity of Niamey (Niger). This paper deals with aerosol optical thicknesses and size distributions derived from ...

Y. Fouquart; B. Bonnel; M. Chaoui Roquai; R. Santer; A. Cerf

1987-01-01T23:59:59.000Z

16

Aerosol Observing System (AOS) Handbook  

E-Print Network (OSTI)

DISCLAIMER This report was prepared as an account of work sponsored by the U.S. Government. Neither the United States nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the U.S. Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect

A. Jefferson

2011-01-01T23:59:59.000Z

17

Observed Aerosol Radiative Forcings: Comparison for Natural...  

NLE Websites -- All DOE Office Websites (Extended Search)

are from 1997, when the El Nio suppressed the rainfall in that region and biomass burning was widespread in the area. These observations are compared to those observed during...

18

Background Stratospheric Aerosol Variations Deduced from Satellite Observations  

Science Conference Proceedings (OSTI)

The Stratospheric Aerosol and Gas Experiment II (SAGE II) aerosol products from 1998 to 2004 have been analyzed for the tendency of changes in background stratospheric aerosol properties. The aerosol extinction coefficient E has apparently ...

Yu Liu; Xuepeng Zhao; Weiliang Li; Xiuji Zhou

2012-04-01T23:59:59.000Z

19

Satellite observations of the seasonal cycles of absorbing aerosols in Africa related to the monsoon rainfall, 1995e2008  

E-Print Network (OSTI)

to the monsoon rainfall, 1995e2008 M. de Graaf a,*, L.G. Tilstra a , I. Aben b , P. Stammes a a Royal Netherlands: Absorbing aerosols Remote sensing African monsoon Precipitation a b s t r a c t The link between the African Monsoon systems and aerosol loading in Africa is studied using multi-year satellite observations of UV

Tilstra, Gijsbert

20

Aerosol Remote Sensing over Clouds Using A-Train Observations  

Science Conference Proceedings (OSTI)

The detection of aerosol above clouds is critical for the estimate of both the aerosol and cloud radiative impacts. In this study, the authors present a new method to retrieve the aerosol properties over clouds that uses the multiangle ...

F. Waquet; J. Riedi; L. C. Labonnote; P. Goloub; B. Cairns; J-L. Deuz; D. Tanr

2009-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol observing systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Multi-year Satellite and Surface Observations of AOD in support of Two-Column Aerosol Project (TCAP) Field Campaign  

SciTech Connect

We use combined multi-year measurements from the surface and space for assessing the spatial and temporal distribution of aerosol properties within a large (~400x400 km) region centered on Cape Cod, Massachusetts, along the East Coast of the United States. The ground-based Aerosol Robotic Network (AERONET) measurements at Marthas Vineyard Coastal Observatory (MVCO) site and Moderate Resolution Imaging Spectrometer (MODIS) sensors on board the Terra and Aqua satellites provide horizontal and temporal variations of aerosol optical depth, while the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) offers the altitudes of aerosol-layers. The combined ground-based and satellite measurements indicated several interesting features among which were the large differences in the aerosol properties observed in July and February. We applied the climatology of aerosol properties for designing the Two-Column Aerosol Project (TCAP), which is supported by the U.S. Department of Energys (DOEs) Atmospheric Radiation Measurement (ARM) Program. The TCAP field campaign involves 12-month deployment (started July 1, 2012) of the ground-based ARM Mobile Facility (AMF) and Mobile Aerosol Observing System (MAOS) on Cape Cod and complimentary aerosol observations from two research aircraft: the DOE Gulfstream-1 (G-1) and the National Aeronautics and Space Administration (NASA) B200 King Air. Using results from the coordinated G-1 and B200 flights during the recent (July, 2012) Intensive Observation Period, we demonstrated that the G-1 in situ measurements and B200 active remote sensing can provide complementary information on the temporal and spatial changes of the aerosol properties off the coast of North America.

Kassianov, Evgueni I.; Chand, Duli; Berg, Larry K.; Fast, Jerome D.; Tomlinson, Jason M.; Ferrare, R.; Hostetler, Chris A.; Hair, John

2012-11-01T23:59:59.000Z

22

Retrieval of Aerosol Optical Depth above Clouds from OMI Observations: Sensitivity Analysis and Case Studies  

Science Conference Proceedings (OSTI)

A large fraction of the atmospheric aerosol load reaching the free troposphere is frequently located above low clouds. Most commonly observed aerosols above clouds are carbonaceous particles generally associated with biomass burning and boreal ...

Omar Torres; Hiren Jethva; P. K. Bhartia

2012-03-01T23:59:59.000Z

23

A Critical Examination of the Observed First Aerosol Indirect Effect  

Science Conference Proceedings (OSTI)

The relative change in cloud droplet number concentration with respect to the relative change in aerosol number concentration, ?, is an indicator of the strength of the aerosol indirect effect and is commonly used in models to parameterize this ...

Hongfei Shao; Guosheng Liu

2009-04-01T23:59:59.000Z

24

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

NLE Websites -- All DOE Office Websites (Extended Search)

An Observed Signature of Aerosol Effect on Cloud Droplet Radii from a 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 1993. Diurnal, monthly, seasonal and interannual variability of aerosol (optical depth and Angstrom coefficient) and cloud (optical depth and effective radius) have been analyzed. We have correlated an "aerosol index" computed from clear-sky observations of MFRSR with cloud droplet mean effective radius to study the

25

Ionization detection system for aerosols  

DOE Patents (OSTI)

This invention relates to an improved smoke-detection system of the ionization-chamber type. In the preferred embodiment, the system utilizes a conventional detector head comprising a measuring ionization chamber, a reference ionization chamber, and a normally non-conductive gas triode for discharging when a threshold concentration of airborne particulates is present in the measuring chamber. The improved system utilizes a measuring ionization chamber which is modified to minimize false alarms and reductions in sensitivity resulting from changes in ambient temperature. In the preferred form of the modification, an annular radiation shield is mounted about the usual radiation source provided to effect ionization in the measuring chamber. The shield is supported by a bimetallic strip which flexes in response to changes in ambient temperature, moving the shield relative to the source so as to vary the radiative area of the source in a manner offsetting temperature-induced variations in the sensitivity of the chamber.

Jacobs, Martin E. (Chillicothe, OH)

1977-01-01T23:59:59.000Z

26

Development of a Global Validation Package for Satellite Oceanic Aerosol Optical Thickness Retrieval Based on AERONET Observations and Its Application to NOAA/NESDIS Operational Aerosol Retrievals  

Science Conference Proceedings (OSTI)

In this paper, a global validation package for satellite aerosol optical thickness retrieval using the Aerosol Robotic Network (AERONET) observations as ground truth is described. To standardize the validation procedure, the optimum timespace ...

Tom X-P. Zhao; Larry L. Stowe; Alexander Smirnov; David Crosby; John Sapper; Charles R. McClain

2002-02-01T23:59:59.000Z

27

Observations and Calculations of Aerosol Heating over the Arabian Sea during MONEX  

Science Conference Proceedings (OSTI)

Radiation flux observations were obtained during a flight of the NCAR Electra over the Arabian Sea during MONEX when aerosols were present, and these observations have been compared with theoretical calculations based upon simultaneously observed ...

Robert O. Ellingson; George N. Serafino

1984-02-01T23:59:59.000Z

28

On Surface Temperature, Greenhouse Gases, and Aerosols: Models and Observations  

Science Conference Proceedings (OSTI)

The effect of changes in atmospheric carbon dioxide concentrations and sulphate aerosols on near-surface temperature is investigated using a version of the Hadley Centre atmospheric model coupled to a mixed layer ocean. The scattering of sunlight ...

J. F. B. Mitchell; R. A. Davis; W. J. Ingram; C. A. Senior

1995-10-01T23:59:59.000Z

29

Observed Impact of Atmospheric Aerosols on the Surface Energy Budget  

Science Conference Proceedings (OSTI)

Atmospheric aerosols scatter and potentially absorb incoming solar radiation, thereby reducing the total amount of radiation reaching the surface and increasing the fraction that is diffuse. The partitioning of incoming energy at the surface into ...

Allison L. Steiner; Dori Mermelstein; Susan J. Cheng; Tracy E. Twine; Andrew Oliphant

2013-09-01T23:59:59.000Z

30

Cloud Activating Properties of Aerosol Observed during CELTIC  

Science Conference Proceedings (OSTI)

Measurements of aerosol size distribution, chemical composition, and cloud condensation nuclei (CCN) concentration were performed during the Chemical Emission, Loss, Transformation, and Interactions with Canopies (CELTIC) field program at Duke ...

Craig A. Stroud; Athanasios Nenes; Jose L. Jimenez; Peter F. DeCarlo; J. Alex Huffman; Roelof Bruintjes; Eiko Nemitz; Alice E. Delia; Darin W. Toohey; Alex B. Guenther; Sreela Nandi

2007-02-01T23:59:59.000Z

31

Observed impact of atmospheric aerosols on the surface energy budget  

Science Conference Proceedings (OSTI)

Atmospheric aerosols scatter and potentially absorb incoming solar radiation, thereby reducing the total amount of radiation reaching the surface and increasing the fraction that is diffuse. The partitioning of incoming energy at the surface into ...

Allison L. Steiner; Dori Mermelstein; Susan J. Cheng; Tracy E. Twine; Andrew Oliphant

32

Organic aerosol components observed in Northern Hemispheric datasets from Aerosol Mass Spectrometry  

E-Print Network (OSTI)

In this study we compile and present results from the factor analysis of 43 Aerosol Mass Spectrometer (AMS) datasets (27 of the datasets are reanalyzed in this work). The components from all sites, when taken together, ...

Kroll, Jesse

33

The Segregation of Aerosols by Cloud-Nucleating Activity. Part II: Observation of an Urban Aerosol  

Science Conference Proceedings (OSTI)

The submicron aerosol of metropolitan Seattle was segregated into CCN and non-CCN fractions by a high-flux thermal diffusion cloud chamber in series with a dichotomous separator. Each segregated fraction of the five-hour daily sample was ...

Lee Harrison

1985-04-01T23:59:59.000Z

34

Operational Aerosol Observations (AEROBS) from AVHRR/3 On Board NOAA-KLM Satellites  

Science Conference Proceedings (OSTI)

Since 1988, the National Oceanic and Atmospheric Administration (NOAA) has provided operational aerosol observations (AEROBS) from the Advanced Very High Resolution Radiometer (AVHRR/2) on board the afternoon NOAA satellites [nominal equator ...

Alexander Ignatov; John Sapper; Stephen Cox; Istvan Laszlo; Nicholas R. Nalli; Katherine B. Kidwell

2004-01-01T23:59:59.000Z

35

Early Radar Echoes from Ultragiant Aerosol in a Cumulus Congestus: Modeling and Observations  

Science Conference Proceedings (OSTI)

The growth of ultragiant aerosol (UGA) in a Lagrangian framework within a simulated three-dimensional cloud is analyzed and compared with radar and aircraft observations of a cumulus congestus collected during the Small Cumulus Microphysics Study ...

Sonia G. Lasher-Trapp; Charles A. Knight; Jerry M. Straka

2001-12-01T23:59:59.000Z

36

Constraining cloud lifetime effects of aerosols using A-Train satellite observations  

Science Conference Proceedings (OSTI)

Aerosol indirect effects have remained the largest uncertainty in estimates of the radiative forcing of past and future climate change. Observational constraints on cloud lifetime effects are particularly challenging since it is difficult to separate aerosol effects from meteorological influences. Here we use three global climate models, including a multi-scale aerosol-climate model PNNL-MMF, to show that the dependence of the probability of precipitation on aerosol loading, termed the precipitation frequency susceptibility (S{sub pop}), is a good measure of the liquid water path response to aerosol perturbation ({lambda}), as both Spop and {lambda} strongly depend on the magnitude of autoconversion, a model representation of precipitation formation via collisions among cloud droplets. This provides a method to use satellite observations to constrain cloud lifetime effects in global climate models. S{sub pop} in marine clouds estimated from CloudSat, MODIS and AMSR-E observations is substantially lower than that from global climate models and suggests a liquid water path increase of less than 5% from doubled cloud condensation nuclei concentrations. This implies a substantially smaller impact on shortwave cloud radiative forcing (SWCF) over ocean due to aerosol indirect effects than simulated by current global climate models (a reduction by one-third for one of the conventional aerosol-climate models). Further work is needed to quantify the uncertainties in satellite-derived estimates of S{sub pop} and to examine S{sub pop} in high-resolution models.

Wang, Minghuai; Ghan, Steven J.; Liu, Xiaohong; Ecuyer, Tristan L.; Zhang, Kai; Morrison, H.; Ovchinnikov, Mikhail; Easter, Richard C.; Marchand, Roger; Chand, Duli; Qian, Yun; Penner, Joyce E.

2012-08-15T23:59:59.000Z

37

Sampling Characteristics of an Aircraft-Borne Aerosol Inlet System  

Science Conference Proceedings (OSTI)

When sampling aerosol particles from aircraft, the inlet system is the most critical item because it can strongly modify the number concentration, size distribution, and chemical composition of the particles. In this investigation, the authors ...

M. Hermann; F. Stratmann; M. Wilck; A. Wiedensohler

2001-01-01T23:59:59.000Z

38

Aerosols: Smoke and Mirrors of the Climate System  

NLE Websites -- All DOE Office Websites (Extended Search)

Aerosols: Smoke and Mirrors of the Climate System Speaker(s): Dr. Harshvardhan Date: May 16, 2011 - 3:00pm Location: 90-3075 Seminar HostPoint of Contact: Surabi Menon Solid and...

39

Observations of Secondary Organic Aerosol Production and Soot Aging under Atmospheric Conditions Using a Novel Environmental Aerosol Chamber  

E-Print Network (OSTI)

Secondary organic aerosols (SOA) comprise a substantial fraction of the total global aerosol budget. While laboratory studies involving smog chambers have advanced our understanding of the formation mechanisms responsible for SOA, our knowledge of the processes leading to SOA production under ambient gaseous and particulate concentrations as well as the impact these aerosol types have on climate is poorly understood. Although the majority of atmospheric aerosols scatter radiation either directly or indirectly by serving as cloud condensation nuclei, soot is thought to have a significant warming effect through absorption. Like inorganic salts, soot may undergo atmospheric transformation through the vapor condensation of non-volatile gaseous species which will alter both its chemical and physical properties. Typical smog chamber studies investigating the formation and growth of SOA as well as the soot aging process are temporally limited by the initial gaseous concentrations injected into the chamber environment. Furthermore, data interpretation from such experiments is generally restricted to the singular gaseous species under investigation. This dissertation discusses the use of a new aerosol chamber designed to study the formation and growth of SOA and soot aging under atmospherically relevant conditions. The Ambient Aerosol Chamber for Evolution Studies (AACES) was deployed at three field sites where size and hygroscopic growth factor (HGF) of ammonium sulfate seed particles was monitored over time to examine the formation and growth of SOA. Similar studies investigating the soot aging process were also conducted in Houston, TX. It is shown that during the ambient growth of ammonium sulfate seed particles, as particle size increases, hygroscopic growth factors decrease considerably resulting in a significant organic mass fraction in the particle phase concluding an experiment. Observations of soot aging show an increase in measured size, HGF, mass and single scattering albedo. Ambient growth rate comparisons with chamber growth yielded similar trends verifying the use of AACES to study aerosol aging. Based on the results from this study, it is recommended that AACES be employed in future studies involving the production and growth of SOA and soot aging under ambient conditions in order to bridge the gaps in our current scientific knowledge.

Glen, Crystal

2010-12-01T23:59:59.000Z

40

Aerosol optical thickness retrieval from satellite observation using support vector regression  

Science Conference Proceedings (OSTI)

Processing of data recorded by the MODIS sensors on board the Terra and Aqua satellites has provided AOT maps that in some cases show low correlations with ground-based data recorded by the AERONET. Application of SVR techniques to MODIS data is a promising, ... Keywords: MODIS, aerosol optical thickness, earth observation, remote sensing, support vector regression

Thi Nhat Thanh Nguyen; Simone Mantovani; Piero Campalani; Mario Cavicchi; Maurizio Bottoni

2010-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol observing systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

"Radiative Closure Studies for Clear Skies During the ARM 2003 Aerosol Intensive Observation Period"  

SciTech Connect

The Department of Energy's Atmospheric Radiation Measurement (ARM) program sponsored a large intensive observation period (IOP) to study aerosol during the month of May 2003 around the Southern Great Plains (SGP) Climate Research Facility (CRF) in north central Oklahoma. Redundant measurements of aerosol optical properties were made using different techniques at the surface as well as in vertical profile with sensors aboard two aircraft. One of the principal motivations for this experiment was to resolve the disagreement between models and measurements of diffuse horizontal broadband shortwave irradiance at the surface, especially for modest aerosol loading. This paper focuses on using the redundant aerosol and radiation measurements during this IOP to compare direct beam and diffuse horizontal broadband shortwave irradiance measurements and models at the surface for a wide range of aerosol cases that occurred during 30 clear-sky periods on 13 days of May 2003. Models and measurements are compared over a large range of solar-zenith angles. Six different models are used to assess the relative agreement among them and the measurements. Better agreement than previously achieved appears to be the result of better specification of input parameters and better measurements of irradiances than in prior studies. Biases between modeled and measured direct irradiances are less than 1%, and biases between modeled and measured diffuse irradiances are less than 2%.

J. J. Michalsky, G. P. Anderson, J. Barnard, J. Delamere, C. Gueymard, S. Kato, P. Kiedron, A. McComiskey, and P. Ricchiazzi

2006-04-01T23:59:59.000Z

42

Aircraft Observations of Sub-cloud Aerosol and Convective Cloud Physical Properties  

E-Print Network (OSTI)

This research focuses on aircraft observational studies of aerosol-cloud interactions in cumulus clouds. The data were collected in the summer of 2004, the spring of 2007 and the mid-winter and spring of 2008 in Texas, central Saudi Arabia and Istanbul, Turkey, respectively. A set of 24 pairs of sub-cloud aerosol and cloud penetration data are analyzed. Measurements of fine and coarse mode aerosol concentrations from 3 different instruments were combined and fitted with lognormal distributions. The fit parameters of the lognormal distributions are compared with cloud droplet effective radii retrieved from 260 cloud penetrations. Cloud condensation nuclei (CCN) measurements for a subset of 10 cases from the Istanbul region are compared with concentrations predicted from aerosol size distributions. Ammonium sulfate was assumed to represent the soluble component of aerosol with dry sizes smaller than 0.5 mm and sodium chloride for aerosol larger than 0.5 mm. The measured CCN spectrum was used to estimate the soluble fraction. The correlations of the measured CCN concentration with the predicted CCN concentration were strong (R2 > 0.89) for supersaturations of 0.2, 0.3 and 0.6%. The measured concentrations were typically consistent with an aerosol having a soluble fraction between roughly 0.5 and 1.0, suggesting a contribution of sulfate or some other similarly soluble inorganic compound. The predicted CCN were found to vary by +or-3.7% when the soluble fraction was varied by 0.1. Cumulative aerosol concentrations at cutoff dry diameters of 1.1, 0.1 and 0.06 mm were found to be correlated with cloud condensation nuclei concentrations but not with maximum cloud base droplet concentrations. It is also shown that in some cases the predominant mechanisms involved in the formation of precipitation were altered and modified by the aerosol properties. This study suggests that CCN-forced variations in cloud droplet number concentration can change the effective radius profile and the type of precipitation hydrometeors. These differences may have a major impact on the global hydrological cycle and energy budget.

Axisa, Duncan

2009-12-01T23:59:59.000Z

43

A General Systems Theory for Atmospheric Flows and Atmospheric Aerosol Size Distribution  

E-Print Network (OSTI)

Atmospheric flows exhibit selfsimilar fractal spacetime fluctuations manifested as the fractal geometry to global cloud cover pattern and inverse power law form for power spectra of meteorological parameters such as windspeed, temperature, rainfall etc. Inverse power law form for power spectra indicate long-range spacetime correlations or non-local connections and is a signature of selforganised criticality generic to dynamical systems in nature such as river flows, population dynamics, heart beat patterns etc. The author has developed a general systems theory which predicts the observed selforganised criticality as a signature of quantumlike chaos in dynamical systems. The model predictions are (i) The fractal fluctuations can be resolved into an overall logarithmic spiral trajectory with the quasiperiodic Penrose tiling pattern for the internal structure. (ii) The probability distribution represents the power (variance) spectrum for fractal fluctuations and follows universal inverse power law form incorporating the golden mean. Such a result that the additive amplitudes of eddies when squared represent probability distribution is observed in the subatomic dynamics of quantum systems such as the electron or photon. Therefore the irregular or unpredictable fractal fluctuations exhibit quantumlike chaos. (iii) Atmospheric aerosols are held in suspension by the vertical velocity distribution (spectrum). The atmospheric aerosol size spectrum is derived in terms of the universal inverse power law characterizing atmospheric eddy energy spectrum. Model predicted spectrum is in agreement with the following two experimentally determined atmospheric aerosol data sets, (i) SAFARI 2000 CV-580 Aerosol Data, Dry Season 2000 (CARG) (ii) World Data Centre Aerosols data sets for the three stations Ny {\\AA}lesund, Pallas and Hohenpeissenberg.

A. M. Selvam

2009-08-17T23:59:59.000Z

44

Design and Implementation of the Radioactive Aerosol's Concentration Measurement System Based on Virtual Training  

Science Conference Proceedings (OSTI)

A Virtual Training System of radioactive aerosol 's concentration measurement is constructed based on Virtual Reality. Firstly, 3-d geometric models about radioactive aerosol's outer environment, detector, intelligent scaler and air sampling pump etc. ... Keywords: Virtual Training, Radioactivity, Aerosol, Radiation Field component

Hui Wei-hua; Huang Chang-qiang; Ding Da-li

2011-07-01T23:59:59.000Z

45

Increase of Cloud Droplet Size with Aerosol Optical Depth: An Observational and Modeling Study  

SciTech Connect

Cloud droplet effective radius (DER) is generally negatively correlated with aerosol optical depth (AOD) as a proxy of cloud condensation nuclei. In this study, cases of positive correlation were found over certain portions of the world by analyzing the Moderate Resolution Imaging Spectroradiometer (MODIS) satellite products, together with a general finding that DER may increase or decrease with aerosol loading depending on environmental conditions. The slope of the correlation between DER and AOD is driven primarily by water vapor amount, which explains 70% of the variance in our study. Various potential artifacts that may cause the positive relation are investigated including water vapor swelling, partially cloudy, atmospheric dynamics, cloud three-dimensional (3-D) and surface influence effects. None seems to be the primary cause for the observed phenomenon, although a certain degree of influence exists for some of the factors. Analyses are conducted over seven regions around the world representing different types of aerosols and clouds. Only two regions show positive dependence of DER on AOD, near coasts of the Gulf of Mexico and South China Sea, which implies physical processes may at work. Using a 2-D spectral-bin microphysics Goddard Cumulus Ensemble model (GCE) which incorporated a reformulation of the Khler theory, two possible physical mechanisms are hypothesized. They are related to the effects of slightly soluble organics (SSO) particles and giant CCNs. Model simulations show a positive correlation between DER and AOD, due to a decrease in activated aerosols with an increasing SSO content. Addition of a few giant CCNs also increases the DER. Further investigations are needed to fully understand and clarify the observed phenomenon.

Yuan, Tianle; Li, Zhanqing; Zhang, Renyi; Fan, Jiwen

2008-02-21T23:59:59.000Z

46

Retrieval of Key Aerosol Optical Parameters from Spectral Direct and Diffuse Irradiances Observed by a Radiometer with Nonideal Cosine Response Characteristic  

Science Conference Proceedings (OSTI)

The spectral direct and diffuse irradiances observed by a radiometer with a horizontal surface detector have been frequently used to study aerosol optical parameters, such as aerosol optical thickness (?aer) and single scattering albedo (?). Such ...

Pradeep Khatri; Tamio Takamura; Akihiro Yamazaki; Yutaka Kondo

2012-05-01T23:59:59.000Z

47

ARM - Measurement - Aerosol concentration  

NLE Websites -- All DOE Office Websites (Extended Search)

concentration concentration 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 : Aerosol concentration A measure of the amount of aerosol particles (e.g. number, mass, volume) per unit volume of air. Categories Aerosols Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments AOS : Aerosol Observing System CSPHOT : Cimel Sunphotometer CPC : Condensation Particle Counter IAP : In-situ Aerosol Profiles (Cessna Aerosol Flights) TDMA : Tandem Differential Mobility Analyzer

48

ARM - Measurement - Aerosol absorption  

NLE Websites -- All DOE Office Websites (Extended Search)

absorption absorption 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 : Aerosol absorption The process in which radiation energy is retained by aerosols. Categories Aerosols Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments AOS : Aerosol Observing System CSPHOT : Cimel Sunphotometer IAP : In-situ Aerosol Profiles (Cessna Aerosol Flights) PSAP : Particle Soot Absorption Photometer PASS : Photoacoustic Soot Spectrometer External Instruments OMI : Ozone Monitoring Instrument

49

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

Science Conference Proceedings (OSTI)

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.

Wang, Jian (Ph.D., Environmental Sciences Department)

2010-05-12T23:59:59.000Z

50

Variability of Absorption and Optical Properties of Key Aerosol Types Observed in Worldwide Locations  

Science Conference Proceedings (OSTI)

Aerosol radiative forcing is a critical, though variable and uncertain, component of the global climate. Yet climate models rely on sparse information of the aerosol optical properties. In situ measurements, though important in many respects, ...

Oleg Dubovik; Brent Holben; Thomas F. Eck; Alexander Smirnov; Yoram J. Kaufman; Michael D. King; Didier Tanr; Ilya Slutsker

2002-02-01T23:59:59.000Z

51

The Use of Direct Observations over the Aerosol Particle Size Distribution for Inverting Lidar Data  

Science Conference Proceedings (OSTI)

The work is concerned with the inversion of horizontal lidar data into the aerosol particle size distribution (APSD). The aerosol is assumed to consist of spherical particles of continental and oceanic origin. The particular refraction index is ...

Kusiel S. Shifrin; Ilia G. Zolotov

2003-10-01T23:59:59.000Z

52

Observations and Modeling of the Surface Aerosol Radiative Forcing during UAE2  

Science Conference Proceedings (OSTI)

Aerosol radiative forcing in the Persian Gulf region is derived from data collected during the United Arab Emirates (UAE) Unified Aerosol Experiment (UAE2). This campaign took place in August and September of 2004. The landsea-breeze circulation ...

K. M. Markowicz; P. J. Flatau; J. Remiszewska; M. Witek; E. A. Reid; J. S. Reid; A. Bucholtz; B. Holben

2008-09-01T23:59:59.000Z

53

Observations and Modeling of Shallow Convective Clouds: Implications for the Indirect Aerosol Effects  

NLE Websites -- All DOE Office Websites (Extended Search)

Observations Observations and Modeling of Shallow Convective Clouds: Implications for the Indirect Aerosol Effects Sylwester Arabas 1 , Joanna Slawinska 1 , Wojciech Grabowski 2 , Hugh Morrison 2 , Hanna Pawlowska 1 1 : Institute of Geophysics, University of Warsaw, Poland 2 : National Center for Atmospheric Research, Boulder, Colorado, USA 348 constants for reference state and lateral boundary conditions 349 ibcx=icyx 350 ibcy=icyy*j3 351 ibcz=icyz 352 irlx=irelx 353 irly=irely*j3 354 irdbc=0 355 fcr0=fcr0*icorio 356 itdl=0 357 tdt=40.*3600. 358 u0tdl=u00 359 360 361 constants for thermodynamics 362 c bv=sqrt(st*g) 363 bv=st 364 st=bv**2/g 365 cp=3.5*rg 366 cap=rg/cp 367 pr00=rg*rh00*tt00

54

Implementation of a lidar system and its usage in characterization of aerosols in the atmospheric column  

Science Conference Proceedings (OSTI)

Light Detection and Ranging (LIDAR) is a recent remote sensing system which has been gradually expanding as a network among the countries actively concerned about the atmospheric contaminants, earth radiation budget, rain variations, clean air index, ... Keywords: AERONET station, Lidar system, aerosol optical depth, aerosol size distribution, air quality index, planetary boundary layer

Javier Mndez-Rodrguez; Hamed Parsiani

2009-06-01T23:59:59.000Z

55

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

NLE Websites -- All DOE Office Websites (Extended Search)

Facility (AMF) and the Mobile Aerosol Observing System (MAOS) will be deployed on Cape Cod (MA) for a 12-month period starting in the summer of 2012 in order to quantify aerosol...

56

Aerosol-Cloud-Radiation Interaction Studies with GEOS-4 Model and Comparison with Observations .  

E-Print Network (OSTI)

??Increasing human population and rapid urbanization in the last two decades have caused a sharp rise in anthropogenic aerosols particularly over South and East Asia. (more)

Bhattacharjee, Partha Sarathi

2011-01-01T23:59:59.000Z

57

Aerosol-Cloud-Radiation Interaction Studies with GEOS-4 model and Comparison with Observations.  

E-Print Network (OSTI)

?? Increasing human population and rapid urbanization in the last two decades have caused a sharp rise in anthropogenic aerosols particularly over South and East (more)

Bhattacharjee, Partha Sarathi

2011-01-01T23:59:59.000Z

58

A Long-Term Record of Aerosol Optical Depth from TOMS Observations and Comparison to AERONET Measurements  

Science Conference Proceedings (OSTI)

Observations of backscattered near-ultraviolet radiation from the Total Ozone Mapping Spectrometer (TOMS) on board the Nimbus-7 (197992) and the Earth Probe (mid-1996 to present) satellites have been used to derive a long-term record of aerosol ...

O. Torres; P. K. Bhartia; J. R. Herman; A. Sinyuk; Paul Ginoux; Brent Holben

2002-02-01T23:59:59.000Z

59

Simulating Aerosols Using a Chemical Transport Model with Assimilation of Satellite Aerosol Retrievals: Methodology for INDOEX  

E-Print Network (OSTI)

A system for simulating aerosols has been developed using a chemical transport model together with an assimilation of satellite aerosol retrievals. The methodology and model components are described in this paper, and the modeled distribution of aerosols for the Indian Ocean Experiment (INDOEX) is presented by Rasch et al. [this issue]. The system generated aerosol forecasts to guide deployment of ships and aircraft during INDOEX. The system consists of the Model of Atmospheric Transport and Chemistry (MATCH) combined with an assimilation package developed for applications in atmospheric chemistry. MATCH predicts the evolution of sulfate, carbonaceous, and mineral dust aerosols, and it diagnoses the distribution of sea salt aerosols. The model includes a detailed treatment of the sources, chemical transformation, transport, and deposition of the aerosol species. The aerosol forecasts involve a two-stage process. During the assimilation phase the total column aerosol optical depth (AOD) is estimated from the model aerosol fields. The model state is then adjusted to improve the agreement between the simulated AOD and satellite retrievals of AOD. During the subsequent integration phase the aerosol fields are evolved using meteorological fields from an external model. Comparison of the modeled AOD against estimates of the AOD from INDOEX Sun photometer data show that the differences in daily means are #0.03 # 0.06. Although the initial application is limited to the Indian Ocean, the methodology could be extended to derive global aerosol analyses combining in situ and remotely sensed aerosol observations.

William D. Collins; Phillip J. Rasch; Brian E. Eaton; Boris V. Khattatov; Jean-francois Lamarque; C. Zender

2001-01-01T23:59:59.000Z

60

Do We Observe Aerosol Impacts on DSDs in Strongly Forced Tropical Thunderstorms?  

Science Conference Proceedings (OSTI)

Rain drop size distributions retrieved from polarimetric radar measurements over regularly occurring thunderstorms over the islands north of Darwin, Australia, are used to test if aerosol contributions to the probability distributions of the drop ...

P. T. May; V. N. Bringi; M. Thurai

2011-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol observing systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Integrating and Interpreting Aerosol Observations and Models within the PARAGON Framework  

Science Conference Proceedings (OSTI)

Given the breadth and complexity of available data, constructing a measurement-based description of global tropospheric aerosols that will effectively confront and constrain global three-dimensional models is a daunting task. Because data are ...

Thomas P. Ackerman; Amy J. Braverman; David J. Diner; Theodore L. Anderson; Ralph A. Kahn; John V. Martonchik; Joyce E. Penner; Philip J. Rasch; Bruce A. Wielicki; Bin Yu

2004-10-01T23:59:59.000Z

62

Climate response of the South Asian monsoon system to anthropogenic aerosols  

Science Conference Proceedings (OSTI)

The equilibrium climate response to the total effects (direct, indirect and semi-direct effects) of aerosols arising from anthropogenic and biomass burning emissions on the South Asian summer monsoon system is studied using a coupled atmosphere-slab ocean model. Our results suggest that anthropogenic and biomass burning aerosols generally induce a reduction in mean summer monsoon precipitation over most parts of the Indian subcontinent, strongest along the western coastline of the Indian peninsula and eastern Nepal region, but modest increases also occur over the north western part of the subcontinent. While most of the noted reduction in precipitation is triggered by increased emissions of aerosols from anthropogenic activities, modest increases in the north west are mostly associated with decreases in local emissions of aerosols from forest fire and grass fire sources. Anthropogenic aerosols from outside Asia also contribute to the overall reduction in precipitation but the dominant contribution comes from aerosol sources within Asia. Local emissions play a more important role in the total rainfall response to anthropogenic aerosol sources during the early monsoon period, whereas both local as well as remote emissions of aerosols play almost equally important roles during the later part of the monsoon period. While precipitation responses are primarily driven by local aerosol forcing, regional surface temperature changes over the region are strongly influenced by anthropogenic aerosols from sources further away (non-local changes). Changes in local anthropogenic organic and black carbon emissions by as much as a factor of two (preserving their ratio) produce the same basic signatures in the model's summer monsoon temperature and precipitation responses.

Ganguly, Dilip; Rasch, Philip J.; Wang, Hailong; Yoon, Jin-Ho

2012-07-13T23:59:59.000Z

63

Fast and Slow Responses of the South Asian Monsoon System to Anthropogenic Aerosols  

Science Conference Proceedings (OSTI)

Using a global climate model with fully predictive aerosol life cycle, we investigate the fast and slow responses of the South Asian monsoon system to anthropogenic aerosol forcing. Our results show that the feedbacks associated with sea surface temperature (SST) change caused by aerosols play a more important role than the aerosol's direct impact on radiation, clouds and land surface (rapid adjustments) in shaping the total equilibrium climate response of the monsoon system to aerosol forcing. Inhomogeneous SST cooling caused by anthropogenic aerosols eventually reduces the meridional tropospheric temperature gradient and the easterly shear of zonal winds over the region, slowing down the local Hadley cell circulation, decreasing the northward moisture transport, and causing a reduction in precipitation over South Asia. Although total responses in precipitation are closer to the slow responses in general, the fast component dominates over land areas north of 25N. Our results also show an east-west asymmetry in the fast responses to anthropogenic aerosols causing increases in precipitation west of 80E but decreases east of it.

Ganguly, Dilip; Rasch, Philip J.; Wang, Hailong; Yoon, Jin-Ho

2012-09-25T23:59:59.000Z

64

Addition of Tropospheric Chemistry and Aerosols to the NCAR Community Climate System Model  

SciTech Connect

Atmospheric chemistry and aerosols have several important roles in climate change. They affect the Earth's radiative balance directly: cooling the earth by scattering sunlight (aerosols) and warming the Earth by trapping the Earth's thermal radiation (methane, ozone, nitrous oxide, and CFCs are greenhouse gases). Atmospheric chemistry and aerosols also impact many other parts of the climate system: modifying cloud properties (aerosols can be cloud condensation nuclei), fertilizing the biosphere (nitrogen species and soil dust), and damaging the biosphere (acid rain and ozone damage). In order to understand and quantify the effects of atmospheric chemistry and aerosols on the climate and the biosphere in the future, it is necessary to incorporate atmospheric chemistry and aerosols into state-of-the-art climate system models. We have taken several important strides down that path. Working with the latest NCAR Community Climate System Model (CCSM), we have incorporated a state-of-the-art atmospheric chemistry model to simulate tropospheric ozone. Ozone is not just a greenhouse gas, it damages biological systems including lungs, tires, and crops. Ozone chemistry is also central to the oxidizing power of the atmosphere, which destroys a lot of pollutants in the atmosphere (which is a good thing). We have also implemented a fast chemical mechanism that has high fidelity with the full mechanism, for significantly reduced computational cost (to facilitate millennium scale simulations). Sulfate aerosols have a strong effect on climate by reflecting sunlight and modifying cloud properties. So in order to simulate the sulfur cycle more fully in CCSM simulations, we have linked the formation of sulfate aerosols to the oxidizing power of the atmosphere calculated by the ozone mechanisms, and to dimethyl sulfide emissions from the ocean ecosystem in the model. Since the impact of sulfate aerosols depends on the relative abundance of other aerosols in the atmosphere, we also implemented interactive simulation of nitrate, sea-salt, black carbon, and both primary and secondary organic aerosols into CCSM (using assumed size distributions). These new capabilities are opening the door to studies of the role atmospheric chemistry and aerosols in climate change, and their impact on the biosphere, that were previously impossible.

Cameron-Smith, P; Lamarque, J; Connell, P; Chuang, C; Rotman, D; Taylor, J

2005-11-14T23:59:59.000Z

65

Impact of Aerosols on Atmospheric Attenuation Loss in Central Receiver Systems: Preprint  

Science Conference Proceedings (OSTI)

Atmospheric attenuation loss between the heliostat field and receiver has been recognized as a significant source of loss in Central Receiver Systems. In clear sky situations, extinction of Direct Normal Irradiance (DNI) is primarily by aerosols in the atmosphere. When aerosol loading is high close to the surface the attenuation loss between heliostat and receivers is significantly influenced by the amount of aerosols present on a particular day. This study relates measured DNI to aerosol optical depths close to the surface of the earth. The model developed in the paper uses only measured DNI to estimate the attenuation between heliostat and receiver in a central receiver system. The requirement that only a DNI measurement is available potentially makes the model a candidate for widespread use.

Sengupta, M.; Wagner, M. J.

2011-08-01T23:59:59.000Z

66

ARM - Field Campaign - Aerosol Life Cycle IOP at BNL  

NLE Websites -- All DOE Office Websites (Extended Search)

govCampaignsAerosol Life Cycle IOP at BNL govCampaignsAerosol Life Cycle IOP at BNL Campaign Links Images Wiki 2011 ASR STM Presentation: Sedlacek 2011 ASR STM Presentation: Springston 2010 ASR Fall Meeting: Sedlacek News, June 14, 2011: Next-generation Aerosol-sampling Stations to Head for India Related Campaigns Aerosol Life Cycle: Chemical Ionization Mass Spectrometer - CIMS 2011.07.10, Lee, OSC Aerosol Life Cycle: HR-ToF-AMS 2011.06.15, Zhang, OSC Aerosol Life Cycle: ARM Mobile Facility 2 Aerosol Observing System 2011.06.15, Sedlacek, OSC Aerosol Life Cycle: UV-APS and Nano-SMPS 2011.06.10, Hallar, 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 IOP at BNL 2011.06.01 - 2011.08.31 Lead Scientist : Arthur Sedlacek For data sets, see below.

67

ARM AOS Processing Status and Aerosol Intensive Properties VAP  

NLE Websites -- All DOE Office Websites (Extended Search)

Andrews, and P. J. Sheridan National Oceanic and Atmospheric Administration Boulder, Colorado Abstract The Atmospheric Radiation Measurement (ARM) Aerosol Observing System (AOS)...

68

Top-of-Atmosphere Direct Radiative Effect of Aerosols over Global Oceans from Merged CERES and MODIS Observations  

Science Conference Proceedings (OSTI)

The direct radiative effect of aerosols (DREA) is defined as the difference between radiative fluxes in the absence and presence of aerosols. In this study, the direct radiative effect of aerosols is estimated for 46 months (March 2000December ...

Norman G. Loeb; Natividad Manalo-Smith

2005-09-01T23:59:59.000Z

69

Emission-Induced Nonlinearities in the Global Aerosol System: Results from the ECHAM5-HAM Aerosol-Climate Model  

Science Conference Proceedings (OSTI)

In a series of simulations with the global ECHAM5-HAM aerosol-climate model, the response to changes in anthropogenic emissions is analyzed. Traditionally, additivity is assumed in the assessment of the aerosol climate impact, as the underlying ...

Philip Stier; Johann Feichter; Silvia Kloster; Elisabetta Vignati; Julian Wilson

2006-08-01T23:59:59.000Z

70

Absorbing Aerosols and Summer Monsoon Evolution over South Asia: An Observational Portrayal  

Science Conference Proceedings (OSTI)

The South Asian haze builds up from December to May, is mostly of anthropogenic origin, and absorbs part of the solar radiation. The influence of interannual variations of absorbing aerosols over the Indo-Gangetic Plain in May on the Indian ...

Massimo Bollasina; Sumant Nigam; K-M. Lau

2008-07-01T23:59:59.000Z

71

The influence of HVAC systems on secondary organic aerosol formation Michael S. Waring1  

E-Print Network (OSTI)

The influence of HVAC systems on secondary organic aerosol formation Michael S. Waring1 , Jeffrey A, ventilation, and air- conditioning (HVAC) system. This study models the influence of HVAC systems on SOA. The most influential HVAC parameters are the flow rates, particle filtration, and indoor temperature

Siegel, Jeffrey

72

AERONET: The Aerosol Robotic Network  

DOE Data Explorer (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

73

Aerosol Sampling System for Collection of Capstone Depleted Uranium Particles in a High-Energy Environment  

SciTech Connect

The Capstone Depleted Uranium Aerosol Study was undertaken to obtain aerosol samples resulting from a kinetic-energy cartridge with a large-caliber depleted uranium (DU) penetrator striking an Abrams or Bradley test vehicle. The sampling strategy was designed to (1) optimize the performance of the samplers and maintain their integrity in the extreme environment created during perforation of an armored vehicle by a DU penetrator, (2) collect aerosols as a function of time post-impact, and (3) obtain size-classified samples for analysis of chemical composition, particle morphology, and solubility in lung fluid. This paper describes the experimental setup and sampling methodologies used to achieve these objectives. Custom-designed arrays of sampling heads were secured to the inside of the target in locations approximating the breathing zones of the vehicle commander, loader, gunner, and driver. Each array was designed to support nine filter cassettes and nine cascade impactors mounted with quick-disconnect fittings. Shielding and sampler placement strategies were used to minimize sampler loss caused by the penetrator impact and the resulting fragments of eroded penetrator and perforated armor. A cyclone train was used to collect larger quantities of DU aerosol for chemical composition and solubility. A moving filter sample was used to obtain semicontinuous samples for depleted uranium concentration determination. Control for the air samplers was provided by five remotely located valve control and pressure monitoring units located inside and around the test vehicle. These units were connected to a computer interface chassis and controlled using a customized LabVIEW engineering computer control program. The aerosol sampling arrays and control systems for the Capstone study provided the needed aerosol samples for physicochemical analysis, and the resultant data were used for risk assessment of exposure to DU aerosol.

Holmes, Thomas D.; Guilmette, Raymond A.; Cheng, Yung-Sung; Parkhurst, MaryAnn; Hoover, Mark D.

2009-03-01T23:59:59.000Z

74

A Small Portable MieRayleigh Lidar System to Measure Aerosol Optical and Spatial Properties  

Science Conference Proceedings (OSTI)

The characteristics of a small, lightweight portable lidar system for measuring aerosol (Mie) scatter at wavelengths of 1064 and 532 nm are described. It uses a 20-Hz Nd:YAG pulsed laser as a source and a 12.7-cm-diameter telescope as a receiver. ...

J. N. Porter; B. R. Lienert; S. K. Sharma; H. W. Hubble

2002-11-01T23:59:59.000Z

75

An Ocean Observing System for Climate  

Science Conference Proceedings (OSTI)

Designs and implementation are proceeding for a Global Ocean Observing System (GOOS) and a Global Climate Observing System (GCOS). The initial design for the ocean component of the GCOS, which is also the climate module of the GOOS, was completed ...

Worth D. Nowlin Jr.; Neville Smith; George Needler; Peter K. Taylor; Robert Weller; Ray Schmitt; Liliane Merlivat; Alain Vzina; Arthur Alexiou; Michael McPhaden; Massaaki Wakatsuchi

1996-10-01T23:59:59.000Z

76

Secondary organic aerosol from ozone-initiated reactions with terpene-rich household products  

E-Print Network (OSTI)

analysis of competition between aerosol particle removal andof secondary organic aerosol. Part I: ?-pinene/ozone system.data when measuring ambient aerosol. Aerosol Science and

Coleman, Beverly K.

2008-01-01T23:59:59.000Z

77

Response of California temperature to regional anthropogenic aerosol changes  

E-Print Network (OSTI)

to regional anthropogenic aerosol changes T. Novakov, T.W.indicator of anthropogenic aerosols with observed surfacetemperature increase. Seasonal aerosol concentration trends

Novakov, T.

2008-01-01T23:59:59.000Z

78

Atmospheric Aerosols  

NLE Websites -- All DOE Office Websites (Extended Search)

Tom Kirchstetter with aerosol measurement instrument Atmospheric Aerosols Atmospheric aerosol research at LBNL seeks to understand the air quality and climate impacts of particles...

79

GNSS radio occultation constellation observing system experiments  

Science Conference Proceedings (OSTI)

Observing system experiments within the operational ECMWF data assimilation framework have been performed for summer 2008 when the largest recorded number of GNSS radio occultation observations from both operational and experimental satellites ...

Peter Bauer; Gbor Radnti; Sean Healy; Carla Cardinali

80

Automated Surface Observing System: Standby Power Options  

NLE Websites -- All DOE Office Websites (Extended Search)

Automated Automated Surface Observing System Standby Options Power Automated Surface Observing System (ASOS) General System Description * Self contained group of sensors and data gathering equipment that produces an automated weather observation * Weather observations support aviation, climate data, non government weather operations, public consumption, etc. * Initial deployment began in 1991 and continued through 1997 * Located at 884 sites nationwide, normally at airports * System has two distinct subsystems: Field installed equipment (DCP & Sensor Group) and an indoor processor (ACU) with peripherals * Separate facility power for DCP & Sensors and ACU 1 * measure and collect data * Located on the airport * back up group for 10 minutes * Currently pl

Note: This page contains sample records for the topic "aerosol observing systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

On the Aerosol Particle Size Distribution Spectrum in Alaskan Air Mass Systems: Arctic Haze and Non-Haze Episodes  

Science Conference Proceedings (OSTI)

Aerosols in central Alaskan winter air mass system were classified according to size by diffusive separation and light-scattering spectrometry. Particles entering central Alaska from the Pacific Marine environment had number concentrations ...

Glenn E. Shaw

1983-05-01T23:59:59.000Z

82

GEO Secretariat Global Earth Observing System of  

E-Print Network (OSTI)

Secretariat Vegetation greenness profiles North America Vegetation Annual Greenness Profiles 100 120 140 160;© GEO Secretariat GEO 2009-11 Work Plan ­ Related Task DA-09-05: Global Carbon Observation and Analysis System Implement a global carbon observation and analysis system addressing the three components

83

Aerosol Remote Duct-Sealing System - lbl.gov  

Available for licensing for fields of use other than sealing HVAC systems. REFERENCE NUMBER: IB-1029. SEE THESE ...

84

Limits to the Aerosol Indirect Radiative Effect Derived from Observations of Ship Tracks  

Science Conference Proceedings (OSTI)

One-kilometer Advanced Very High Resolution Radiometer (AVHRR) observations of the effects of ships on low-level clouds off the west coast of the United States are used to derive limits for the degree to which clouds might be altered by increases ...

James A. Coakley Jr.; Christopher D. Walsh

2002-02-01T23:59:59.000Z

85

A Study of the Aerosol Effect on a Cloud Field with Simultaneous Use of GCM Modeling and Satellite Observation  

Science Conference Proceedings (OSTI)

The indirect effect of aerosols was simulated by a GCM for nonconvective water clouds and was compared with remote sensing results from the Advanced Very High Resolution Radiometer (AVHRR) satellite-borne sensor for January, April, July, and ...

Kentaroh Suzuki; Teruyuki Nakajima; Atusi Numaguti; Toshihiko Takemura; Kazuaki Kawamoto; Akiko Higurashi

2004-01-01T23:59:59.000Z

86

Retrieval of Aerosol Scattering and Absorption Properties from Photopolarimetric Observations over the Ocean during the CLAMS Experiment  

Science Conference Proceedings (OSTI)

The extensive set of measurements performed during the Chesapeake Lighthouse and Aircraft Measurements for Satellites (CLAMS) experiment provides a unique opportunity to evaluate aerosol retrievals over the ocean from multiangle, multispectral ...

Jacek Chowdhary; Brian Cairns; Michael I. Mishchenko; Peter V. Hobbs; Glenn F. Cota; Jens Redemann; Ken Rutledge; Brent N. Holben; Ed Russell

2005-04-01T23:59:59.000Z

87

Multiyear Observations of the Tropical Atlantic Atmosphere: Multidisciplinary Applications of the NOAA Aerosols and Ocean Science Expeditions  

Science Conference Proceedings (OSTI)

This paper gives an overview of a unique set of ship-based atmospheric data acquired over the tropical Atlantic Ocean during boreal spring and summer as part of ongoing National Oceanic and Atmospheric Administration (NOAA) Aerosols and Ocean Science ...

Nicholas R. Nalli; Everette Joseph; Vernon R. Morris; Christopher D. Barnet; Walter W. Wolf; Daniel Wolfe; Peter J. Minnett; Malgorzata Szczodrak; Miguel A. Izaguirre; Rick Lumpkin; Hua Xie; Alexander Smirnov; Thomas S. King; Jennifer Wei

2011-06-01T23:59:59.000Z

88

The Retrieval of Profiles of Particulate Extinction from Cloud-Aerosol Lidar Infrared Pathfinder Satellite Observations (CALIPSO) Data: Algorithm Description  

Science Conference Proceedings (OSTI)

This work describes the algorithms used for the fully automated retrieval of profiles of particulate extinction coefficients from the attenuated backscatter data acquired by the lidar on board the Cloud-Aerosol Lidar Infrared Pathfinder Satellite ...

Stuart A. Young; Mark A. Vaughan

2009-06-01T23:59:59.000Z

89

Field Observations of In-Cloud Nucleation and the Modification of Atmospheric Aerosol Size Distributions after Cloud Evaporation  

Science Conference Proceedings (OSTI)

The authors measured aerosol and droplet size distributions in the range from 0.1 to 50 m, concentrations and sizes of precipitation particles, concentrations of condensation nuclei, and state parameters in and in the vicinity of a towering ...

A. J. Alkezweeny

1995-12-01T23:59:59.000Z

90

Increase in background stratospheric aerosol observed with lidar at Mauna Loa Observatory and Boulder, Colorado - article no. L15808  

Science Conference Proceedings (OSTI)

The stratospheric aerosol layer has been monitored with lidars at Mauna Loa Observatory in Hawaii and Boulder in Colorado since 1975 and 2000, respectively. Following the Pinatubo volcanic eruption in June 1991, the global stratosphere has not been perturbed by a major volcanic eruption providing an unprecedented opportunity to study the background aerosol. Since about 2000, an increase of 4-7% per year in the aerosol backscatter in the altitude range 20-30 km has been detected at both Mauna Loa and Boulder. This increase is superimposed on a seasonal cycle with a winter maximum that is modulated by the quasi-biennial oscillation (QBO) in tropical winds. Of the three major causes for a stratospheric aerosol increase: volcanic emissions to the stratosphere, increased tropical upwelling, and an increase in anthropogenic sulfur gas emissions in the troposphere, it appears that a large increase in coal burning since 2002, mainly in China, is the likely source of sulfur dioxide that ultimately ends up as the sulfate aerosol responsible for the increased backscatter from the stratospheric aerosol layer. The results are consistent with 0.6-0.8% of tropospheric sulfur entering the stratosphere.

Hofmann, D.; Barnes, J.; O'Neill, M.; Trudeau, M.; Neely, R. [NOAA, Boulder, CO (United States)

2009-08-15T23:59:59.000Z

91

Aerosol Properties from Multi-spectral and Multi-angular Aircraft 4STAR Observations: Expected Advantages and Challenges  

SciTech Connect

The airborne Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research (4STAR) is developed to retrieve aerosol microphysical and optical properties from multi-angular and multi-spectral measurements of sky radiance and direct-beam sun transmittance. The necessarily compact design of the 4STAR may cause noticeable apparent enhancement of sky radiance at small scattering angles. We assess the sensitivity of expected 4STAR-based aerosol retrieval to such enhancement by applying the operational AERONET retrieval code and constructed synthetic 4STARlike data. Also, we assess the sensitivity of the broadband fluxes and the direct aerosol radiative forcing to uncertainties in aerosol retrievals associated with the sky radiance enhancement. Our sensitivity study results suggest that the 4STARbased aerosol retrieval has limitations in obtaining detailed information on particle size distribution and scattering phase function. However, these limitations have small impact on the retrieved bulk optical parameters, such as the asymmetry factor (up to 4%, or 0.02) and single-scattering albedo (up to 2%, or 0.02), and the calculated direct aerosol radiative forcing (up to 6%, or 2 Wm-2).

Kassianov, Evgueni I.; Flynn, Connor J.; Redemann, Jens; Schmid, Beat; Russell, P. B.; Sinyuk, Alexander

2012-11-01T23:59:59.000Z

92

Aerosols and solar energy  

DOE Green Energy (OSTI)

A brief description is presented of the involvement of the Solar Energy Research Institute (SERI) in atmospheric research, including aerosol characterization and modeling. The use of both rigorous and simple models for radiation transport is described. Modeled broadband solar irradiance data are shown to illustrate the important influence that aerosols have on the energy available to solar systems and the economics of solar systems design. Standard aerosol measurement methods for solar applications are discussed along with the need for improved instrumentation and methods.

Bird, R. E.; Hulstrom, R. L.

1979-01-01T23:59:59.000Z

93

Methodology to quantify leaks in aerosol sampling system components  

E-Print Network (OSTI)

Filter holders and continuous air monitors (CAMs) are used extensively in the nuclear industry. It is important to minimize leakage in these devices and in recognition of this consideration, a limit on leakage for sampling systems is specified in ANSI/HPS N13.1-1999; however the protocol given in the standard is really germane to measurement of significant leakage, e.g., several percent of the sampling flow rate. In the present study, a technique for quantifying leakage was developed and that approach was used to measure the sealing integrity of a CAM and two kinds of filter holders. The methodology involves use of sulfur hexafluoride as a tracer gas with the device being tested operated under dynamic flow conditions. The leak rates in these devices were determined in the pressure range from 2.49 kPa (10 In. H2O) vacuum to 2.49 kPa (10 In. H2O) pressure at a typical flow rate of 56.6 L/min (2 cfm). For the two filter holders, the leak rates were less than 0.007% of the nominal flow rate. The leak rate in the CAM was less than 0.2% of the nominal flow rate. These values are well within the limit prescribed in the ANSI standard, which is 5% of the nominal flow rate. Therefore the limit listed in the ANSI standard should be reconsidered as lower values can be achieved, and the methodology presented herein can be used to quantify lower leakage values in sample collectors and analyzers. A theoretical analysis was also done to determine the nature of flow through the leaks and the amount of flow contribution by the different possible mechanisms of flow through leaks.

Vijayaraghavan, Vishnu Karthik

2003-08-01T23:59:59.000Z

94

Factors influencing the microphysics and radiative properties of liquid-dominated Arctic clouds: insight from observations of aerosol and clouds during ISDAC  

SciTech Connect

Aircraft measurements during the Indirect and Semi-Direct Aerosol Campaign (ISDAC) in April 2008 are used to investigate aerosol indirect effects in Arctic clouds. Two aerosol-cloud regimes are considered in this analysis: single-layer stratocumulus cloud with below-cloud aerosol concentrations (N{sub a}) below 300 cm{sup -3} on April 8 and April 26-27 (clean cases); and inhomogeneous layered cloud with N{sub a} > 500 cm{sup -3} below cloud base on April 19-20, concurrent with a biomass burning episode (polluted cases). Vertical profiles through cloud in each regime are used to determine average cloud microphysical and optical properties. Positive correlations between the cloud droplet effective radius (Re) and cloud optical depth ({tau}) are observed for both clean and polluted cases, which are characteristic of optically-thin, non-precipitating clouds. Average Re values for each case are {approx} 6.2 {mu}m, despite significantly higher droplet number concentrations (Nd) in the polluted cases. The apparent independence of Re and Nd simplifies the description of indirect effects, such that {tau} and the cloud albedo (A) can be described by relatively simple functions of the cloud liquid water path. Adiabatic cloud parcel model simulations show that the marked differences in Na between the regimes account largely for differences in droplet activation, but that the properties of precursor aerosol also play a role, particularly for polluted cases where competition for vapour amongst the more numerous particles limits activation to larger and/or more hygroscopic particles. The similarity of Re for clean and polluted cases is attributed to compensating droplet growth processes for different initial droplet size distributions.

Earle, Michael; Liu, Peter S.; Strapp, J. Walter; Zelenyuk, Alla; Imre, D.; McFarquhar, Greg; Shantz, Nicole C.; Leaitch, W. R.

2011-11-04T23:59:59.000Z

95

The web-PLOP observation prioritisation system  

E-Print Network (OSTI)

We present a description of the automated system used by RoboNet to prioritise follow up observations of microlensing events to search for planets. The system keeps an up-to-date record of all public data from OGLE and MOA together with any existing RoboNet data and produces new PSPL fits whenever new data arrives. It then uses these fits to predict the current or future magnitudes of events, and selects those to observe which will maximise the probability of detecting planets for a given telescope and observing time. The system drives the RoboNet telescopes automatically based on these priorities, but it is also designed to be used interactively by human observers. The prioritisation options, such as telescope/instrument parameters, observing conditions and available time can all be controlled via a web-form, and the output target list can also be customised and sorted to show the parameters that the user desires. The interactive interface is available at http://www.artemis-uk.org/web-PLOP/

Colin Snodgrass; Yiannis Tsapras; Rachel Street; Daniel Bramich; Keith Horne; Martin Dominik; Alasdair Allan

2008-05-14T23:59:59.000Z

96

ARM - Measurement - Aerosol backscattered radiation  

NLE Websites -- All DOE Office Websites (Extended Search)

backscattered radiation backscattered radiation 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 : Aerosol backscattered radiation The scattering of radiant energy into the hemisphere of space bounded by a plane normal to the direction of the incident radiation and lying on the same side as the incident ray. Categories Aerosols Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments AOS : Aerosol Observing System MPL : Micropulse Lidar NEPHELOMETER : Nephelometer

97

Atmospheric Aerosols  

NLE Websites -- All DOE Office Websites (Extended Search)

measuring equipment Atmospheric Aerosols Atmospheric aerosol research at Berkeley Lab seeks to understand the air quality and climate impacts of particles in the atmosphere. On...

98

Aerosol Characterization Data from the Asian Pacific Regional Aerosol Characterization Project (ACE-Asia)  

DOE Data Explorer (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.

99

GUIDE TO CALCULATING TRANSPORT EFFICIENCY OF AEROSOLS IN OCCUPATIONAL AIR SAMPLING SYSTEMS  

SciTech Connect

This report will present hand calculations for transport efficiency based on aspiration efficiency and particle deposition losses. Because the hand calculations become long and tedious, especially for lognormal distributions of aerosols, an R script (R 2011) will be provided for each element examined. Calculations are provided for the most common elements in a remote air sampling system, including a thin-walled probe in ambient air, straight tubing, bends and a sample housing. One popular alternative approach would be to put such calculations in a spreadsheet, a thorough version of which is shared by Paul Baron via the Aerocalc spreadsheet (Baron 2012). To provide greater transparency and to avoid common spreadsheet vulnerabilities to errors (Burns 2012), this report uses R. The particle size is based on the concept of activity median aerodynamic diameter (AMAD). The AMAD is a particle size in an aerosol where fifty percent of the activity in the aerosol is associated with particles of aerodynamic diameter greater than the AMAD. This concept allows for the simplification of transport efficiency calculations where all particles are treated as spheres with the density of water (1 g?cm-3). In reality, particle densities depend on the actual material involved. Particle geometries can be very complicated. Dynamic shape factors are provided by Hinds (Hinds 1999). Some example factors are: 1.00 for a sphere, 1.08 for a cube, 1.68 for a long cylinder (10 times as long as it is wide), 1.05 to 1.11 for bituminous coal, 1.57 for sand and 1.88 for talc. Revision 1 is made to correct an error in the original version of this report. The particle distributions are based on activity weighting of particles rather than based on the number of particles of each size. Therefore, the mass correction made in the original version is removed from the text and the calculations. Results affected by the change are updated.

Hogue, M.; Hadlock, D.; Thompson, M.; Farfan, E.

2013-11-12T23:59:59.000Z

100

Evolution of organic aerosol mass spectra upon heating: implications for OA phase and partitioning behavior  

E-Print Network (OSTI)

and Seinfeld, J. H. : Organic aerosol formation from theJ. : A large organic aerosol source in the free troposphereand Worsnop, D. R. : Organic aerosol components observed in

Cappa, Christopher D.

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol observing systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

BNL | Aerosol Lifecycle IOP  

NLE Websites -- All DOE Office Websites (Extended Search)

Program Program Aerosol Life Cycle IOP The primary objectives that make up the Aerosol Life Cycle IOP can be broken down into three categories: Scientific; Logistical; and GVAX preparation. Scientific Objectives The science goals are to conduct intensive aerosol observations in a region exposed to anthropogenic, biogenic, and marine emissions with atmospheric processing times depending on air mass trajectories and time of day. Take advantage of new instruments in the MAOS (e.g., SP2, HR-PTRMS, ACSM, Trace Gas Suite, PASS-3, Aethelometer, UHSAS). Within this broad umbrella are embedded three main foci: Aerosol light absorption: How does the aerosol mass absorption coefficient (absorption per unit mass of BC) vary with atmospheric processing? Do observations agree with a shell-core model?

102

Design of an Unattended Environmental Aerosol Sampling and Analysis System for Gaseous Centrifuge Enrichment Plants  

Science Conference Proceedings (OSTI)

The resources of the IAEA continue to be challenged by the rapid, worldwide expansion of nuclear energy production. Gaseous centrifuge enrichment plants (GCEPs) represent an especially formidable dilemma to the application of safeguard measures, as the size and enrichment capacity of GCEPs continue to escalate. During the early part of the 1990's, the IAEA began to lay the foundation to strengthen and make cost-effective its future safeguard regime. Measures under Part II of 'Programme 93+2' specifically sanctioned access to nuclear fuel production facilities and environmental sampling by IAEA inspectors. Today, the Additional Protocol grants inspection and environmental sample collection authority to IAEA inspectors at GCEPs during announced and low frequency unannounced (LFUA) inspections. During inspections, IAEA inspectors collect environmental swipe samples that are then shipped offsite to an analytical laboratory for enrichment assay. This approach has proven to be an effective deterrence to GCEP misuse, but this method has never achieved the timeliness of detection goals set forth by IAEA. Furthermore it is questionable whether the IAEA will have the resources to even maintain pace with the expansive production capacity of the modern GCEP, let alone improve the timeliness in reaching current safeguards conclusions. New safeguards propositions, outside of familiar mainstream safeguard measures, may therefore be required that counteract the changing landscape of nuclear energy fuel production. A new concept is proposed that offers rapid, cost effective GCEP misuse detection, without increasing LFUA inspection access or introducing intrusive access demands on GCEP operations. Our approach is based on continuous onsite aerosol collection and laser enrichment analysis. This approach mitigates many of the constraints imposed by the LFUA protocol, reduces the demand for onsite sample collection and offsite analysis, and overcomes current limitations associated with the in-facility misuse detection devices. Onsite environmental sample collection offers the ability to collect fleeting uranium hexafluoride emissions before they are lost to the ventilation system or before they disperse throughout the facility, to become deposited onto surfaces that are contaminated with background and historical production material. Onsite aerosol sample collection, combined with enrichment analysis, provides the unique ability to quickly detect stepwise enrichment level changes within the facility, leading to a significant strengthening of facility misuse deterence. We report in this paper our study of several GCEP environmental sample release scenarios and simulation results of a newly designed aerosol collection and particle capture system that is fully integrated with the Laser Ablation, Absorbance Ratio Spectrometry (LAARS) uranium particle enrichment analysis instrument that was developed at the Pacific Northwest National Laboratory.

Anheier, Norman C.; Munley, John T.; Alexander, M. L.

2011-07-19T23:59:59.000Z

103

Common Cyber Security Vulnerabilities Observed in Control System...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Common Cyber Security Vulnerabilities Observed in Control System Assessments by the INL NSTB Program Common Cyber Security Vulnerabilities Observed in Control System Assessments by...

104

Impact of anthropogenic aerosols on Indian summer monsoon  

SciTech Connect

Using an interactive aerosol-climate model we find that absorbing anthropogenic aerosols, whether coexisting with scattering aerosols or not, can significantly affect the Indian summer monsoon system. We also show that the influence is reflected in a perturbation to the moist static energy in the sub-cloud layer, initiated as a heating by absorbing aerosols to the planetary boundary layer. The perturbation appears mostly over land, extending from just north of the Arabian Sea to northern India along the southern slope of the Tibetan Plateau. As a result, during the summer monsoon season, modeled convective precipitation experiences a clear northward shift, coincidently in agreement with observed monsoon precipitation changes in recent decades particularly during the onset season. We demonstrate that the sub-cloud layer moist static energy is a useful quantity for determining the impact of aerosols on the northward extent and to a certain degree the strength of monsoon convection.

Wang, Chien; Kim, Dongchul; Ekman, Annica; Barth, Mary; Rasch, Philip J.

2009-11-05T23:59:59.000Z

105

Characterizing the Vertical Distribution of Aerosols Over the ARM SGP Site  

Science Conference Proceedings (OSTI)

This project focused on: 1) evaluating the performance of the DOE ARM SGP Raman lidar system in measuring profiles of water vapor and aerosols, and 2) the use of the Raman lidar measurements of aerosol and water vapor profiles for assessing the vertical distribution of aerosols and water vapor simulated by global transport models and examining diurnal variability of aerosols and water vapor. The highest aerosol extinction was generally observed close to the surface during the nighttime just prior to sunrise. The high values of aerosol extinction are most likely associated with increased scattering by hygroscopic aerosols, since the corresponding average relative humidity values were above 70%. After sunrise, relative humidity and aerosol extinction below 500 m decreased with the growth in the daytime convective boundary layer. The largest aerosol extinction for altitudes above 1 km occurred during the early afternoon most likely as a result of the increase in relative humidity. The water vapor mixing ratio profiles generally showed smaller variations with altitude between day and night. We also compared simultaneous measurements of relative humidity, aerosol extinction, and aerosol optical thickness derived from the ARM SGP Raman lidar and in situ instruments on board a small aircraft flown routinely over the ARM SGP site. In contrast, the differences between the CARL and IAP aerosol extinction measurements are considerably larger. Aerosol extinction derived from the IAP measurements is, on average, about 30-40% less than values derived from the Raman lidar. The reasons for this difference are not clear, but may be related to the corrections for supermicron scattering and relative humidity that were applied to the IAP data. The investigators on this project helped to set up a major field mission (2003 Aerosol IOP) over the DOE ARM SGP site. One of the goals of the mission was to further evaluate the aerosol and water vapor retrievals from this lidar system. Analysis of the aerosol and water vapor data collected by the Raman lidar during the 2003 Aerosol IOP indicated that the sensitivity of the lidar was significantly lower than when the lidar was initially deployed. A detailed analysis after the IOP of the long-term dataset demonstrated that the lidar began degrading in early 2002, and that it lost approximately a factor of 4 in sensitivity between 2002 and 2004. We participated in the development of the remediation plan for the system to restore its initial performance. We conducted this refurbishment and upgrade from May- September 2004. This remediation lead to an increase in the signal-to-noise ratio of 10 and 30 for the Raman lidar's water vapor mixing ratio and aerosol backscatter coefficient data, respectively as compared to the signal strengths when the system was first deployed. The DOE ARM Aerosol Lidar Validation Experiment (ALIVE), which was conducted during September 2005, evaluated the impact of these modifications and upgrades on the SGP Raman lidar measurements of aerosol extinction and optical thickness. The CARL modifications significantly improved the accuracy and temporal resolution of the aerosol measurements. Aerosol extinction profiles measured by the Raman lidar were also used to evaluate aerosol extinction profiles and aerosol optical thickness (AOT) simulated by aerosol models as part of the Aerosol module inter-Comparison in global models (AEROCOM) (http://nansen.ipsl.jussieu.fr/AEROCOM/aerocomhome.html) project. There was a wide range in how the models represent the aerosol extinction profiles over the ARM SGP site, even though the average annual AOT represented by the various models and measured by CARL and the Sun photometer were in general agreement, at least within the standard deviations of the averages. There were considerable differences in the average vertical distributions among the models, even among models that had similar average aerosol optical thickness. Deviations between mean aerosol extinction profiles were generally small (~20-30%) for altitudes above 2 km, and grew consider

Richard Ferrare, Connor Flynn, David Turner

2009-05-05T23:59:59.000Z

106

The Two-Column Aerosol Project (TCAP) Science Plan  

Science Conference Proceedings (OSTI)

The Two-Column Aerosol Project (TCAP) field campaign will provide a detailed set of observations with which to (1) perform radiative and cloud condensation nuclei (CCN) closure studies, (2) evaluate a new retrieval algorithm for aerosol optical depth (AOD) in the presence of clouds using passive remote sensing, (3) extend a previously developed technique to investigate aerosol indirect effects, and (4) evaluate the performance of a detailed regional-scale model and a more parameterized global-scale model in simulating particle activation and AOD associated with the aging of anthropogenic aerosols. To meet these science objectives, the Atmospheric Radiation Measurement (ARM) Climate Research Facility will deploy the ARM Mobile Facility (AMF) and the Mobile Aerosol Observing System (MAOS) on Cape Cod, Massachusetts, for a 12-month period starting in the summer of 2012 in order to quantify aerosol properties, radiation, and cloud characteristics at a location subject to both clear and cloudy conditions, and clean and polluted conditions. These observations will be supplemented by two aircraft intensive observation periods (IOPs), one in the summer and a second in the winter. Each IOP will deploy one, and possibly two, aircraft depending on available resources. The first aircraft will be equipped with a suite of in situ instrumentation to provide measurements of aerosol optical properties, particle composition and direct-beam irradiance. The second aircraft will fly directly over the first and use a multi-wavelength high spectral resolution lidar (HSRL) and scanning polarimeter to provide continuous optical and cloud properties in the column below.

Berkowitz, CM; Berg, LK; Cziczo, DJ; Flynn, CJ; Kassianov, EI; Fast, JD; Rasch, PJ; Shilling, JE; Zaveri, RA; Zelenyuk, A; Ferrare, RA; Hostetler, CA; Cairns, B; Russell, PB; Ervens, B

2011-07-27T23:59:59.000Z

107

CLARREO shortwave observing system simulation experiments of the twenty-first century: Simulator design and implementation  

Science Conference Proceedings (OSTI)

Projected changes in the Earth system will likely be manifested in changes in reflected solar radiation. This paper introduces an operational Observational System Simulation Experiment (OSSE) to calculate the signals of future climate forcings and feedbacks in top-of-atmosphere reflectance spectra. The OSSE combines simulations from the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report for the NCAR Community Climate System Model (CCSM) with the MODTRAN radiative transfer code to calculate reflectance spectra for simulations of current and future climatic conditions over the 21st century. The OSSE produces narrowband reflectances and broadband fluxes, the latter of which have been extensively validated against archived CCSM results. The shortwave reflectance spectra contain atmospheric features including signals from water vapor, liquid and ice clouds, and aerosols. The spectra are also strongly influenced by the surface bidirectional reflectance properties of predicted snow and sea ice and the climatological seasonal cycles of vegetation. By comparing and contrasting simulated reflectance spectra based on emissions scenarios with increasing projected and fixed present-day greenhouse gas and aerosol concentrations, we find that prescribed forcings from increases in anthropogenic sulfate and carbonaceous aerosols are detectable and are spatially confined to lower latitudes. Also, changes in the intertropical convergence zone and poleward shifts in the subsidence zones and the storm tracks are all detectable along with large changes in snow cover and sea ice fraction. These findings suggest that the proposed NASA Climate Absolute Radiance and Refractivity Observatory (CLARREO) mission to measure shortwave reflectance spectra may help elucidate climate forcings, responses, and feedbacks.

Feldman, D.R.; Algieri, C.A.; Ong, J.R.; Collins, W.D.

2011-04-01T23:59:59.000Z

108

The CALIPSO Automated Aerosol Classification and Lidar Ratio Selection Algorithm  

Science Conference Proceedings (OSTI)

Descriptions are provided of the aerosol classification algorithms and the extinction-to-backscatter ratio (lidar ratio) selection schemes for the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) aerosol products. One ...

Ali H. Omar; David M. Winker; Mark A. Vaughan; Yongxiang Hu; Charles R. Trepte; Richard A. Ferrare; Kam-Pui Lee; Chris A. Hostetler; Chieko Kittaka; Raymond R. Rogers; Ralph E. Kuehn; Zhaoyan Liu

2009-10-01T23:59:59.000Z

109

Aerosol properties computed from aircraft-based observations during the ACE-Asia campaign: 2. A case study of lidar ratio closure  

SciTech Connect

For a vertical profile with three distinct layers (marine boundary, pollution and dust layers), observed during the ACE-Asia campaign, we carried out a comparison between the modeled lidar ratio vertical profile and that obtained from co-located airborne NASA AATS-14 sunphotometer and shipborne Micro-Pulse Lidar (MPL) measurements. The vertically resolved lidar ratio was calculated from two size distribution vertical profiles one obtained by inversion of sunphotometer-derived extinction spectra, and one measured in-situ combined with the same refractive index model based on aerosol chemical composition. The aerosol model implies single scattering albedos of 0.78 0.81 and 0.93 0.96 at 0.523 ?m (the wavelength of the lidar measurements), in the pollution and dust layers, respectively. The lidar ratios calculated from the two size distribution profiles agree closely in the dust layer; they are however, significantly lower than the lidar ratios derived from combined lidar and sunphotometer measurements. Uncertainties in aerosol size distributions and refractive index only partly explain these differences, suggesting that particle nonsphericity in this layer is an additional explanation. In the pollution layer, the two size distribution profiles yield lidar ratios that agree within the estimated uncertainties. The retrieved size distributions result in a lidar ratio which is in closer agreement with that derived from lidar/sunphotometer measurements in this layer, with still large differences at certain altitudes (the largest relative difference was 46%). We explain these differences by non-uniqueness of the result of the size distribution retrieval, by a lack of information on the mixing state of particles, and the vertical variability of the particle refractive index.

Kuzmanoski, Maja; Box, M. A.; Schmid, Beat; Box, G. P.; Wang, Jian; Russel, P. R.; Bates, D.; Jonsson, Haf; Welton, E. J.; Seinfeld, J. H.

2007-04-03T23:59:59.000Z

110

Aerosol Laboratory - Nuclear Engineering Division (Argonne)  

NLE Websites -- All DOE Office Websites (Extended Search)

Capabilities > Engineering Capabilities > Engineering Experimentation > Aerosol Laboratory Capabilities Engineering Experimentation Reactor Safety Experimentation Aerosol Experiments System Components Laser Applications Robots Applications Other Facilities Other Capabilities Work with Argonne Contact us For Employees Site Map Help Join us on Facebook Follow us on Twitter NE on Flickr Aerosol Laboratory The Aerosol Laboratory (AL) houses equipment to measure and record the physical parameters necessary to characterize the formation and transport of aerosols. Bookmark and Share The Aerosol Laboratory (AL) has extensive analytic and experimental capabilities to characterize the formation and transport of aerosols formed from the condensation of vapors. Computer codes have been developed to

111

Hydrated and Dried Aerosol-Size-Distribution Measurements from the Particle Measuring Systems FSSP-300 Probe and the Deiced PCASP-100X Probe  

Science Conference Proceedings (OSTI)

Comparisons of particle-size distributions measured by Particle Measuring Systems FSSP-300 and PCASP-100X probes through a range of relative humidities reveal that the deiced PCASP-100X probe dries hydrated submicron aerosols before measurement. ...

J. Walter Strapp; W. R. Leaitch; P. S. K. Liu

1992-10-01T23:59:59.000Z

112

BNL | Atmospheric Systems Research  

NLE Websites -- All DOE Office Websites (Extended Search)

Atmospheric System Research is a DOE observation-based research program Atmospheric System Research is a DOE observation-based research program created to advance process-level understanding of the key interactions among aerosols, clouds, precipitation, radiation, dynamics, and thermodynamics, with the ultimate goal of reducing the uncertainty in global and regional climate simulations and projections. General areas of research at BNL under this program include studies of aerosol and cloud lifecycles, and cloud-aerosol-precipitation interactions. Contact Robert McGraw, 631.344.3086 aerosols Aerosol Life Cycle The strategic focus of the Aerosol Life Cycle research is observation-based process science-examining the properties and evolution of atmospheric aerosols. Observations come from both long-term studies conducted by the

113

Assessment of the Impact of Observations on Analyses Derived from Observing System Experiments  

Science Conference Proceedings (OSTI)

Observing system experiments (OSEs) are commonly used to quantify the impact of different observation types on forecasts produced by a specific numerical weather prediction system. Recently, methods based on degree of freedom for signal (DFS) have ...

Cristina Lupu; Pierre Gauthier; Stphane Laroche

2012-01-01T23:59:59.000Z

114

Evaluating the Direct and Indirect Aerosol Effect on Climate  

NLE Websites -- All DOE Office Websites (Extended Search)

one of the largest uncertainties in climate forcing studies is the effect of aerosols on the earth-atmosphere system. Aerosols affect the radiation budget under both clear...

115

Aerosol Jet Material Deposition for High Resolution Printed ...  

Science Conference Proceedings (OSTI)

Abstract Scope, Aerosol Jet printing, is finding wide use in a number of ... The Aerosol Jet systems deposit a wide variety of functional materials onto a wide...

116

Effect of Aerosol on CloudEnvironment Interactions in Trade Cumulus  

Science Conference Proceedings (OSTI)

This study examines the role of aerosol in mediating interactions between a warm trade cumulus cloud system and the environment that spawns it. Numerical simulations of the observed and well-studied Rain in Cumulus over the Ocean (RICO) field ...

Seoung-Soo Lee; Graham Feingold; Patrick Y. Chuang

2012-12-01T23:59:59.000Z

117

AMBROSia: An Autonomous Model-Based Reactive Observing System  

Science Conference Proceedings (OSTI)

Observing systems facilitate scientific studies by instrumenting the real world and collecting corresponding measurements, with the aim of detecting and tracking phenomena of interest. Our AMBROSia project focuses on a class of observing systems which ...

David Caron; Abhimanyu Das; Amit Dhariwal; Leana Golubchik; Ramesh Govindan; David Kempe; Carl Oberg; Abhishek Sharma; Beth Stauffer; Gaurav Sukhatme; Bin Zhang

2007-05-01T23:59:59.000Z

118

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

SciTech Connect

The ARM Climate Research Facilitys (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 conditions are likely to be very different because of the much more extensive ocean water during M-PACE. The uniformity of the surface conditions during ISDAC greatly simplifies the objective analysis (surface fluxes and precipitation are very weak), so that it can largely rely on the European Centre for Medium-Range Weather Forecasts analysis. The aerosol measurements can also be used as input to the cloud models and to evaluate the aerosol retrievals. By running the cloud models with and without solar absorption by the aerosols, we can determine the semidirect effect of the aerosol on the clouds.

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

2007-11-01T23:59:59.000Z

119

Continuous Observations of Aerosol Profiles with a Two-Wavelength Mie-Scattering Lidar in Guangzhou in PRD2006  

Science Conference Proceedings (OSTI)

Continuous lidar observation was performed in Guangzhou, China, in the Pearl River Delta (PRD) observation campaign in July 2006 (PRD2006), using a two-wavelength Mie-scattering lidar (532 and 1064 nm) with a depolarization measurement channel at ...

Nobuo Sugimoto; Tomoaki Nishizawa; Xingang Liu; Ichiro Matsui; Atsushi Shimizu; Yuanhang Zhang; Young J. Kim; Ruhao Li; Jun Liu

2009-09-01T23:59:59.000Z

120

ATI TDA 5A aerosol generator evaluation  

SciTech Connect

Oil based aerosol ``Smoke`` commonly used for testing the efficiency and penetration of High Efficiency Particulate Air filters (HEPA) and HEPA systems can produce flammability hazards that may not have been previously considered. A combustion incident involving an aerosol generator has caused an investigation into the hazards of the aerosol used to test HEPA systems at Hanford.

Gilles, D.A.

1998-07-27T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol observing systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Observational Studies of Atmospheric Aerosols over Bozeman, Montana, Using a Two-Color Lidar, a Water Vapor DIAL, a Solar Radiometer, and a Ground-Based Nephelometer over a 24-h Period  

Science Conference Proceedings (OSTI)

Coordinated observational data of atmospheric aerosols were collected over a 24-h period between 2300 mountain daylight time (MDT) on 27 August 2009 and 2300 MDT on 28 August 2009 at Bozeman, Montana (45.66N, 111.04W, elevation 1530 m) using a ...

Kevin S. Repasky; John A. Reagan; Amin R. Nehrir; David S. Hoffman; Michael J. Thomas; John L. Carlsten; Joseph A. Shaw; Glenn E. Shaw

2011-03-01T23:59:59.000Z

122

FEASIBILITY OF THE AEROSOL-TO-LIQUID PARTICLE EXTRACTION SYSTEM (ALPES) FOR COLLECTION OF VIABLE FRANCISELLA SP.  

SciTech Connect

Several Biowatch monitoring sites in the Houston area have tested positive for Francisella tularensis and there is a need to determine whether natural occurring Francisella-related microorganism(s) may be responsible for these observed positive reactions. The collection, culturing and characterization of Francisella-related natural microorganisms will provide the knowledge base to improve the future selectivity of Biowatch monitoring for Francisella. The aerosol-to-liquid particle extraction system (ALPES) is a high-efficiency, dual mechanism collection system that utilizes a liquid collection medium for capture of airborne microorganisms. Since the viability of microorganisms is preserved better in liquid medium than on air filters, this project was undertaken to determine whether Francisella philomiragia and Francisella tularensis LVS maintain acceptable viability in the continuous liquid recirculation, high direct current voltage and residual ozone concentrations which occur during ALPES operation. Throughout a series of preliminary trial runs with representative gram-negative and gram-positive microorganisms, several design modifications and improvements to the ALPES optimized liquid handling, electrical stability, sampling and overall performance for biological sampling. Initial testing with Francisella philomiragia showed viability was preserved better in PBS buffer than HBSS buffer. Trial runs at starting cell concentrations of 1.8 x 10{sup 6} and 2.5 x 10{sup 4} CFU/L showed less than a 1-log decrease in viability for F. philomiragia after 24 h in the ALPES. Francisella tularensis LVS (live vaccine strain) was used as a surrogate for virulent F. tularensis in ALPES trial runs conducted at starting cell concentrations of 10{sup 4}, 10{sup 5} and 10{sup 6} CFU/L. F. tularensis LVS was slow-growing and required highly selective growth media to prevent overgrowth by collected airborne microorganisms. In addition, one ALPES unit intake was HEPA filtered during the final trial runs with F. tularensis LVS to further reduce the levels of microbial background. Results from trials with F. tularensis LVS showed about a 1-log loss decrease in CFUs after 24 h, but maintained final cell concentrations in the range of 10{sup 3}-10{sup 4} CFU/L. These results indicate that the ALPES maintains acceptable viability of Francisella sp. in PBS buffer for up to 24 h and is a promising technology for the collection of viable airborne Francisella or Francisella-related cultures which may be observed at Biowatch monitoring sites in the Houston area and elsewhere.

Heitkamp, M

2006-08-07T23:59:59.000Z

123

Recursive controllability and observability tests for large dynamic systems  

Science Conference Proceedings (OSTI)

Controllability and observability criteria for a linear stationary system are used to design recursive tests for slackening the computing system requirements for verification of the controllability and observability of large systems. Practical examples ... Keywords: 02.30.Yy+64.70.+p

E. Yu. Zybin; M. Sh. Misrikhanov; V. N. Ryabchenko

2006-05-01T23:59:59.000Z

124

ARM - Measurement - Aerosol extinction  

NLE Websites -- All DOE Office Websites (Extended Search)

CSPHOT : Cimel Sunphotometer CLDAEROSMICRO : Cloud and Aerosol Microphysical Properties DRI-GND : Desert Research Institute Ground-Based Aerosol Instruments IAP : In-situ Aerosol...

125

An Observing System Simulation Experiment for the Indian Ocean  

Science Conference Proceedings (OSTI)

An integrated in situ Indian Ocean observing system (IndOOS) is simulated using a high-resolution ocean general circulation model (OGCM) with daily mean forcing, including an estimate of subdaily oceanic variability derived from observations. The ...

Gabriel A. Vecchi; Matthew J. Harrison

2007-07-01T23:59:59.000Z

126

An Observation System Using Both Optical Stitching and Video Geo ...  

home \\ technologies \\ optical stitching and video geo registration. Technologies: Ready-to-Sign Licenses: Software: Patents: An Observation System Using Both Optical ...

127

Volcanoes and Climate Effects of Aerosols  

E-Print Network (OSTI)

CONTENTS 8.1 Importance of volcanoes, natural aerosols, and anthropogenic aerosols 341 8.2 Major scientific questions and hypotheses 342 8.2.1 Stratospheric volcanic aerosols and climate 342 8.2.1.1 Source gases for stratospheric aerosols 342 8.2.1.2 Explosiveness and plume history during individual eruptions 343 8.2.1.3 Frequency of eruptions, tectonic setting, rock/ash vs. SO 2 343 8.2.1.4 Gas-to-particle conversion and removal mechanisms 343 8.2.1.5 Radiative properties and climatic effects of stratospheric aerosols 345 8.2.1.6 Needed satellite and in situ measurements 347 8.2.1.6.1 Global observations of stratospheric aerosol optical properties 347 8.2.1.6.2 Lidar measurements of aerosols 347 8.2.2 Volcanic aerosols and stratospheric ozone depletion 349 8.2.3 Climatic effects of t

Hartmann And Mouginis-Mark; Volcanoes; D. L. Hartmann; P. Mouginis-mark; G. J. Bluth; J. A. Coakley; J. Crisp; R. E. Dickinson; P. W. Francis; J. E. Hansen; P. V. Hobbs; B. L. Isacks; Y. J. Kaufman; M. D. King; W. I. Rose; S. Self; L. D. Travis

1999-01-01T23:59:59.000Z

128

Full-Time, Eye-Safe Cloud and Aerosol Lidar Observation at Atmospheric Radiation Measurement Program Sites: Instruments and Data Processing  

Science Conference Proceedings (OSTI)

Atmospheric radiative forcing, surface radiation budget, and top-of-the-atmosphere radiance interpretation involve knowledge of the vertical height structure of overlying cloud and aerosol layers. During the last decade, the U.S. Department of ...

James R. Campbell; Dennis L. Hlavka; Ellsworth J. Welton; Connor J. Flynn; David D. Turner; James D. Spinhirne; V. Stanley Scott III; I. H. Hwang

2002-04-01T23:59:59.000Z

129

Evolution of the Pinatubo Aerosol: Raman Lidar Observations of Particle Optical Depth, Effective Radius, Mass, and Surface Area over Central Europe at 53.4N  

Science Conference Proceedings (OSTI)

The Raman lidar technique has been applied to document the evolution and dissipation of the Pinatubo aerosol between 1991 and 1995. For the first time, profiles of the particle extinction coefficient have been determined with lidar in the ...

A. Ansmann; I. Mattis; U. Wandinger; F. Wagner; J. Reichardt; T. Deshler

1997-11-01T23:59:59.000Z

130

Observations of Lower-Stratospheric CIONO2, HNO3, and Aerosol by the UARS CLAES Experiment between January 1992 and April 1993  

Science Conference Proceedings (OSTI)

This paper discusses simultaneous measurements of stratospheric CIONO2, HNO3, temperature, and aerosol extinction coefficient by the Cryogenic Limb Array Etalon Spectrometer (CLAES) on the NASA Upper Atmosphere Research Satellite (UARS), obtained ...

A. E. Roche; J. B. Kumer; J. L. Mergenthaler; R. W. Nightingale; W. G. Uplinger; G. A. Ely; J. F. Potter; D. J. Wuebbles; P. S. Connell; D. E. Kinnison

1994-10-01T23:59:59.000Z

131

between Photolytic Aerosols and Solar Radiation  

E-Print Network (OSTI)

Since the early 70s chemistry and transport models (ChTMs) have been proposed and improved. Tropospheric ChTMs for trace species are detailed numerical formulations intended to represent the atmospheric system as a whole, accounting for all the individual processes and phenomena that influence climate changes. The development of computer resources and the retrieval of emission inventories and observational data of the species of interest have enhanced the model evolution towards three-dimensional global models that account for more complicated chemical mechanisms, wet and dry deposition phenomena, and interactions and feedback mechanisms between meteorology and atmospheric chemistry. The purpose of this study is to ascertain the sensitivity of the solar radiative field in the atmosphere to absorption and scattering by aerosols. This effort is preliminary to the study of feedback mechanisms between photolytic processes that create and destroy aerosols and the radiation field itself. In this study, a cloud of water-soluble aerosols, randomly distributed in space within hypothetical 1-cm cubes of atmosphere, is generated. A random radius is assigned to each aerosol according to a lognormal size distribution function. The radiative field characterization is analyzed using a Mie scattering code to determine the scattering phase function and the absorption and scattering coefficients of sulfate aerosols, and a Monte Carlo ray-trace code is used to evaluate the radiative exchange. The ultimate goal of the effort is to create a tool to analyze the vertical distribution of absorption by aerosols in order to determine whether or not feedback between photolytic processes and the radiation field needs to be included in a Third Generation Chemistry and Transport model. ii

Mara Santa; Mara Iruzubieta; Mara Santa; Mara Iruzubieta

2001-01-01T23:59:59.000Z

132

Rule-based system architecting of Earth observation satellite systems  

E-Print Network (OSTI)

System architecting is concerned with exploring the tradespace of early, high-level, system design decisions with a holistic, value-centric view. In the last few years, several tools and methods have been developed to ...

Selva Valero, Daniel

2012-01-01T23:59:59.000Z

133

EOS Terra Aerosol and Radiative Flux Validation: An Overview of the Chesapeake Lighthouse and Aircraft Measurements for Satellites (CLAMS) Experiment  

Science Conference Proceedings (OSTI)

NASA developed an Earth Observing System (EOS) to study global change and reduce uncertainties associated with aerosols and other key parameters controlling climate. The first EOS satellite, Terra, was launched in December 1999. The Chesapeake ...

W. L. Smith Jr.; T. P. Charlock; R. Kahn; J. V. Martins; L. A. Remer; P. V. Hobbs; J. Redemann; C. K. Rutledge

2005-04-01T23:59:59.000Z

134

DEVELOPMENT OF A TAMPER RESISTANT/INDICATING AEROSOL COLLECTION SYSTEM FOR ENVIRONMENTAL SAMPLING AT BULK HANDLING FACILITIES  

SciTech Connect

Environmental sampling has become a key component of International Atomic Energy Agency (IAEA) safeguards approaches since its approval for use in 1996. Environmental sampling supports the IAEA's mission of drawing conclusions concerning the absence of undeclared nuclear material or nuclear activities in a Nation State. Swipe sampling is the most commonly used method for the collection of environmental samples from bulk handling facilities. However, augmenting swipe samples with an air monitoring system, which could continuously draw samples from the environment of bulk handling facilities, could improve the possibility of the detection of undeclared activities. Continuous sampling offers the opportunity to collect airborne materials before they settle onto surfaces which can be decontaminated, taken into existing duct work, filtered by plant ventilation, or escape via alternate pathways (i.e. drains, doors). Researchers at the Savannah River National Laboratory and Oak Ridge National Laboratory have been working to further develop an aerosol collection technology that could be installed at IAEA safeguarded bulk handling facilities. The addition of this technology may reduce the number of IAEA inspector visits required to effectively collect samples. The principal sample collection device is a patented Aerosol Contaminant Extractor (ACE) which utilizes electrostatic precipitation principles to deposit particulates onto selected substrates. Recent work has focused on comparing traditional swipe sampling to samples collected via an ACE system, and incorporating tamper resistant and tamper indicating (TRI) technologies into the ACE system. Development of a TRI-ACE system would allow collection of samples at uranium/plutonium bulk handling facilities in a manner that ensures sample integrity and could be an important addition to the international nuclear safeguards inspector's toolkit. This work was supported by the Next Generation Safeguards Initiative (NGSI), Office of Nonproliferation and International Security (NIS), National Nuclear Security Administration (NNSA).

Sexton, L.

2012-06-06T23:59:59.000Z

135

Identification of Wiener systems with binary-valued output observations  

Science Conference Proceedings (OSTI)

This work is concerned with identification of Wiener systems whose outputs are measured by binary-valued sensors. The system consists of a linear FIR (finite impulse response) subsystem of known order, followed by a nonlinear function with a known parametrization ... Keywords: Binary-valued observations, Identification, Joint identifiability, Parameter estimation, Periodic inputs, Sensor thresholds, Wiener systems

Yanlong Zhao; Le Yi Wang; G. George Yin; Ji-Feng Zhang

2007-10-01T23:59:59.000Z

136

CALIPSO-Derived Three-Dimensional Structure of Aerosol over the Atlantic Basin and Adjacent Continents  

Science Conference Proceedings (OSTI)

Accurate modeling of the impact of aerosols on climate requires a detailed understanding of the vertical distribution of aerosols. The CloudAerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) provides continuous high-resolution ...

Aaron M. Adams; Joseph M. Prospero; Chidong Zhang

2012-10-01T23:59:59.000Z

137

The CALIPSO Lidar Cloud and Aerosol Discrimination: Version 2 Algorithm and Initial Assessment of Performance  

Science Conference Proceedings (OSTI)

The CloudAerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) satellite was launched in April 2006 to provide global vertically resolved measurements of clouds and aerosols. Correct discrimination between clouds and aerosols ...

Zhaoyan Liu; Mark Vaughan; David Winker; Chieko Kittaka; Brian Getzewich; Ralph Kuehn; Ali Omar; Kathleen Powell; Charles Trepte; Chris Hostetler

2009-07-01T23:59:59.000Z

138

Observing-Systems Simulation Experiments: Past, Present, and Future  

Science Conference Proceedings (OSTI)

A summary of the history of observing-systems simulation experiments (OSSEs) is presented together with a description of current methodology, its capabilities and limitations, and considerations for the design of future experiments. These ...

Charles P. Arnold Jr.; Clifford H. Dey

1986-06-01T23:59:59.000Z

139

Thermodynamic Properties of Mesoscale Convective Systems Observed during BAMEX  

Science Conference Proceedings (OSTI)

Dropsonde observations from the Bow Echo and Mesoscale Convective Vortex Experiment (BAMEX) are used to document the spatiotemporal variability of temperature, moisture, and wind within mesoscale convective systems (MCSs). Onion-type sounding ...

James Correia Jr.; Raymond W. Arritt

2008-11-01T23:59:59.000Z

140

Integrating spacecraft and aircraft in Earth Observation System architectures  

E-Print Network (OSTI)

The Global Earth Observation System (GEOS) is the essential data gathering network that enables the advancement of Earth science. In recent years, efforts have been made to understand the major GEOS architectural tradeoffs. ...

Suarez, Brandon H

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol observing systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Capturing the content of physics: systems, observables, and experiments  

Science Conference Proceedings (OSTI)

We present a content markup language for physics realized by extending the OMDoc format by an infrastructure for the principal concepts of physics: observables, physical systems, and experiments. The formalization of the description ...

Eberhard R. Hilf; Michael Kohlhase; Heinrich Stamerjohanns

2006-08-01T23:59:59.000Z

142

GPSCellular Drifter Technology for Coastal Ocean Observing Systems  

Science Conference Proceedings (OSTI)

A drifter for observing small spatial and temporal scales of motion in the coastal zone is presented. The drifter uses GPS to determine its position, and the Mobitex terrestrial cellular communications system to transmit the position data in near...

J. Carter Ohlmann; Peter F. White; Andrew L. Sybrandy; P. Peter Niiler

2005-09-01T23:59:59.000Z

143

Control Landscapes for Observable Preparation with Open Quantum Systems  

E-Print Network (OSTI)

A quantum control landscape is defined as the observable as a function(al) of the system control variables. Such landscapes were introduced to provide a basis to understand the increasing number of successful experiments controlling quantum dynamics phenomena. This paper extends the concept to encompass the broader context of the environment having an influence. For the case that the open system dynamics are fully controllable, it is shown that the control landscape for open systems can be lifted to the analysis of an equivalent auxiliary landscape of a closed composite system that contains the environmental interactions. This inherent connection can be analyzed to provide relevant information about the topology of the original open system landscape. Application to the optimization of an observable expectation value reveals the same landscape simplicity observed in former studies on closed systems. In particular, no false sub-optimal traps exist in the system control landscape when seeking to optimize an observable, even in the presence of complex environments. Moreover, a quantitative study of the control landscape of a system interacting with a thermal environment shows that the enhanced controllability attainable with open dynamics significantly broadens the range of the achievable observable values over the control landscape.

Rebing Wu; Alexander Pechen; Herschel Rabitz; Michael Hsieh; Benjamin Tsou

2007-08-16T23:59:59.000Z

144

Flammability and Combustion Behaviors in Aerosols Formed by Industrial Heat Transfer Fluids Produced by the Electrospray Method  

E-Print Network (OSTI)

The existence of flammable aerosols presents a high potential for fire hazards in the process industry. Various industrial fluids, most of which operate at elevated temperatures and pressures, can be atomized when released under high pressure through a small orifice. Because of the complexity in the process of aerosol formation and combustion, the availability of data on aerosol flammability and flame propagation behaviors is still quite limited, making it difficult to evaluate the potential fire and explosion risks from released aerosols in the process industry and develop safety measures for preventing and/or mitigating aerosol hazards. A study is needed to investigate the relationship between aerosol combustion behaviors and the properties of the aerosols. This dissertation presents research on the combustion behaviors of flammable aerosols. Monodisperse aerosols created by industrial heat transfer fluids were generated using electrospray. The characteristics of flame propagations in aerosols and the influence of the presence of fuel droplets in the system are studied in the aerosol ignition tests. Flames in aerosols are characterized by non-uniform shapes and discrete flame fronts. Flames were observed in different burning modes. Droplet evaporation was found to play an important role in aerosol burning modes. Droplet evaporation behaviors and fuel vapor distributions are further related to aerosol droplet size, droplet spacing, movement velocity, and liquid volatility. The burning mode of a global flame with rapid size expansion is considered the most hazardous aerosol combustion scenario. This burning mode requires a smaller droplet size and smaller space between droplets. Larger droplet sizes and spacing may hinder the appearance of global flames. But when the liquid fuel has a certain level of volatility, there is an uneven distribution of fuel vapor in the system and this may cause the unique phenomenon of burning mode variations combined with enhanced flame propagation speed. Using an integrated model, the minimum ignition energy values of aerosols were predicted. The aerosol minimum ignition energy is influenced by the fuel-air equivalence ratio and the droplet size. Higher equivalence ratios, up to 1.0, significantly reduce the minimum ignition energy, while larger droplet sizes result in a higher minimum ignition energy.

Lian, Peng

2011-08-01T23:59:59.000Z

145

Vertical distribution of aerosols in the vicinity of Mexico City during MILAGRO-2006 Campaign  

Science Conference Proceedings (OSTI)

On 7 March 2006, a mobile, ground-based, vertical pointing, elastic lidar system made a North-South transect through the Mexico City basin. Column averaged, aerosol size distribution (ASD) measurements were made on the ground concurrently with the lidar measurements. The ASD ground measurements allowed calculation of the column averaged mass extinction efficiency (MEE) for the lidar system (1064 nm). The value of column averaged MEE was combined with spatially resolved lidar extinction coefficients to produce total aerosol mass concentration estimates with the resolution of the lidar (1.5 m vertical spatial and 1 s temporal). Airborne ASD measurements from DOE G-1 aircraft made later in the day on 7 March 2006, allowed the evaluation of the assumptions of constant ASD with height and time used for estimating the column averaged MEE. The results showed that the aerosol loading within the basin is about twice what is observed outside of the basin. The total aerosol base concentrations observed in the basin are of the order of 200 {mu}g/m{sup 3} and the base levels outside are of the order of 100 {mu}g/m{sup 3}. The local heavy traffic events can introduce aerosol levels near the ground as high as 900 {mu}g/m{sup 3}. The article presents the methodology for estimating aerosol mass concentration from mobile, ground-based lidar measurements in combination with aerosol size distribution measurements. An uncertainty analysis of the methodology is also presented.

Lewandowski, P.A.; Kleinman, L.; Eichinger, W. E.; Holder, H.; Prueger, J.; Wang, J.

2010-02-01T23:59:59.000Z

146

Lessen 2Lessen 2 Earth System Observation:Earth System Observation  

E-Print Network (OSTI)

T k t th E tTracks at the Equator 4 #12;Timing of Adjacent Landsat 5 or 7 Coverage Tracks 5 Adjacent an understanding of the total Earth system, and the effects of natural and human-induced changes on the global Landsat 1 in January 1975J y Radiation Research Satellite Nimbus (launches 1964-1978) ­ Successor

Li, Zhanqing

147

Aerosol size distribution using Lidar data and a typical Lidar assembly  

Science Conference Proceedings (OSTI)

An algorithm is developed and detailed in this paper which determines atmospheric aerosol parameters such as backscatter and extinction coefficients, aerosol optical thickness, and the aerosol size distribution. The algorithm uses the power profile data ... Keywords: LIDAR system, aerosol optical depth, aerosol size distribution, remote sensing

Hamed Parsiani; Javier Mndez

2008-11-01T23:59:59.000Z

148

A cooperative control algorithm for camera based observational systems.  

SciTech Connect

Over the last several years, there has been considerable growth in camera based observation systems for a variety of safety, scientific, and recreational applications. In order to improve the effectiveness of these systems, we frequently desire the ability to increase the number of observed objects, but solving this problem is not as simple as adding more cameras. Quite often, there are economic or physical restrictions that prevent us from adding additional cameras to the system. As a result, we require methods that coordinate the tracking of objects between multiple cameras in an optimal way. In order to accomplish this goal, we present a new cooperative control algorithm for a camera based observational system. Specifically, we present a receding horizon control where we model the underlying optimal control problem as a mixed integer linear program. The benefit of this design is that we can coordinate the actions between each camera while simultaneously respecting its kinematics. In addition, we further improve the quality of our solution by coupling our algorithm with a Kalman filter. Through this integration, we not only add a predictive component to our control, but we use the uncertainty estimates provided by the filter to encourage the system to periodically observe any outliers in the observed area. This combined approach allows us to intelligently observe the entire region of interest in an effective and thorough manner.

Young, Joseph G.

2012-01-01T23:59:59.000Z

149

Sun-Photometer Observations of Aerosol Optical Thickness over the North Atlantic from a Soviet Research Vessel for Validation of Satellite Measurements  

Science Conference Proceedings (OSTI)

This paper deals with the problem of aerosol optical thickness (?A) retrieval using sun-photometer measurements. The results of the theoretical analysis and computer processing of the dataset collected during the 40th cruise of the R/V Akademik ...

Gennady K. Korotaev; Sergey M. Sakerin; Aleksandr M. Ignatov; Larry L. Stowe; E. Paul McClain

1993-10-01T23:59:59.000Z

150

A new climatology of aerosols in the middle and upper stratosphere by alternative analysis of GOMOS observations during 20022006  

Science Conference Proceedings (OSTI)

Recent works have shown how the study of stratospheric background aerosol i.e. in periods uninfluenced by major volcanic eruption seems more complex as it is now performed by more accurate means. We propose a re-analysis of Global Ozone Monitoring by ...

Vernica Salazar, Jean-Baptiste Renard, Alain Hauchecorne, Slimane Bekki, Gwenal Berthet

2013-07-01T23:59:59.000Z

151

Observations of Atmospheric Structure and Dynamics in the Owens Valley of California with a Ground-Based, Eye-Safe, Scanning Aerosol Lidar  

Science Conference Proceedings (OSTI)

First results are presented from the deployment of the NCAR Raman-Shifted Eye-Safe Aerosol Lidar (REAL) in the Owens Valley of California during the Terrain-Induced Rotor Experiment (T-REX) in March and April 2006. REAL operated in rangeheight ...

Stephan F. J. De Wekker; Shane D. Mayor

2009-07-01T23:59:59.000Z

152

BNL | Aerosol Lifecycle Research  

NLE Websites -- All DOE Office Websites (Extended Search)

identified strategic process-science foci: aerosol nucleation and growth and aerosol aging and mixing state. BNL is the lead laboratory responsible for the design and...

153

Aerosol Can Failure  

Science Conference Proceedings (OSTI)

Presentation Title, Aerosol Can Failure ... Abstract Scope, A three-piece, welded seam aerosol can of liquid undercoating material failed catastrophically,...

154

Design and Implementation of a Prototype Data System for Earth Radiation Budget, Cloud, Aerosol, and Chemistry Data  

Science Conference Proceedings (OSTI)

The Earth Observing System (EOS) will collect data from a large number of satellite-borne instruments, beginning later in this decade. To make data accessible to the scientific community, NASA will build an EOS Data and Information System (EOSDIS)...

Bryan A. Baum; Bruce R. Barkstrom

1993-04-01T23:59:59.000Z

155

Observations of temperature, wind, cirrus, and trace gases in the tropical tropopause transition layer during the MJO  

Science Conference Proceedings (OSTI)

Satellite observations of temperature, optically thin cirrus clouds, and trace gases derived from the Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC), Cloud-Aerosol Lidar and Infrared Pathfinder Satellite ...

Katrina S. Virts; John M. Wallace

156

Aerosol Impacts on the Microphysical Growth Processes of Orographic Snowfall  

Science Conference Proceedings (OSTI)

The Regional Atmospheric Modeling System was used to simulate four winter snowfall events over the Park Range of Colorado. For each event, three hygroscopic aerosol sensitivity simulations were performed with initial aerosol profiles representing ...

Stephen M. Saleeby; William R. Cotton; Douglas Lowenthal; Joe Messina

2013-04-01T23:59:59.000Z

157

EVN observations of the lens system B0128+437  

E-Print Network (OSTI)

Previous VLBI observations of the lens system CLASS B0128+437 showed that the lensed source had a triple sub-component structure. However, one of the images looked very different to the others and it has been suggested that this is due to scatter-broadening in the ISM of the lensing galaxy. We present a new 21-cm EVN map of this system, the low frequency compared to previous epochs chosen as the scattering should be more pronounced at this frequency. Analysis of the new map is at an early stage, but the area of scattering in the affected image is extremely obvious. Other points of interest that we seek to explain are the very large sizes of the images (in conflict with the observed spectral turnover at about 1 GHz) and the different position angle of one of the images at different frequencies.

A. D. Biggs

2004-12-30T23:59:59.000Z

158

Response of California temperature to regional anthropogenic aerosol  

NLE Websites -- All DOE Office Websites (Extended Search)

Response of California temperature to regional anthropogenic aerosol Response of California temperature to regional anthropogenic aerosol changes Title Response of California temperature to regional anthropogenic aerosol changes Publication Type Journal Article Year of Publication 2008 Authors Novakov, Tihomir, Thomas W. Kirchstetter, Surabi Menon, and Jeffery Aguiar Journal Geophysical Research Letters Volume 35 Issue 19 Abstract In this paper, we compare constructed records of concentrations of black carbon (BC) - an indicator of anthropogenic aerosols - with observed surface temperature trends in California. Annual average BC concentrations in major air basins in California significantly decreased after about 1990, coincident with an observed statewide surface temperature increase. Seasonal aerosol concentration trends are consistent with observed seasonal temperature trends. These data suggest that the reduction in anthropogenic aerosol concentrations contributed to the observed surface temperature increase. Conversely, high aerosol concentrations may lower surface temperature and partially offset the temperature increase of greenhouse gases.

159

Subarctic atmospheric aerosol composition: 1. Ambient aerosol characterization  

SciTech Connect

Sub-Arctic aerosol was sampled during July 2007 at the Abisko Research Station Stordalen field site operated by the Royal Swedish Academy of Sciences. Located in northern Sweden at 68 latitude and 385 meters above sea level (msl), this site is classified as a semi-continuous permafrost mire. Number density, size distribution, cloud condensation nucleus properties, and chemical composition of the ambient aerosol were determined. Backtrajectories showed that three distinct airmasses were present over Stordalen during the sampling period. Aerosol properties changed and correlated with airmass origin to the south, northeast, or west. We observe that Arctic aerosol is not compositionally unlike that found in the free troposphere at mid-latitudes. Internal mixtures of sulfates and organics, many on insoluble biomass burning and/or elemental carbon cores, dominate the number density of particles from ~200 to 2000 nm aerodynamic diameter. Mineral dust which had taken up gas phase species was observed in all airmasses. Sea salt, and the extent to which it had lost volatile components, was the aerosol type that most varied with airmass.

Friedman, Beth; Herich, Hanna; Kammermann, Lukas; Gross, Deborah S.; Ameth, Almut; Holst, Thomas; Lohmann, U.; Cziczo, Daniel J.

2009-07-10T23:59:59.000Z

160

Design of an ambient aerosol sampling system for high and medium speed applications  

E-Print Network (OSTI)

Two ambient sampling systems were designed and tested for high speed sampling application for a wind speed range of 4.47 m/s to 26.82 m/s. These systems will be used as inlets for sampling of bioaerosol from air. These systems consist of shrouded probes for sampling at higher speeds and omni-directional inlets for low speed ambient sampling. The two systems operate at 780 L/min and 90 L/min. Another system was designed and tested for medium speed ambient sampling. This unit will be used as a reference sampler for speed ranges from zero to 20.12 m/s. This system consists of a Sierra-Andersen SA-246 inlet for sampling at speeds up-to 6.71 m/s (15 mph) and a shrouded probe operating at variable flow rate for sampling in speed range of 6.71 m/s and 20.12 m/s. An aircraft-borne shrouded probe was also tested at wind speeds as high as 50 m/s in an upgraded high speed wind tunnel.

Irshad, Hammad

2002-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol observing systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Assimilation of Satellite Infrared Radiances and Doppler Radar Observations during a Cool Season Observing System Simulation Experiment  

Science Conference Proceedings (OSTI)

An observing system simulation experiment is used to examine the impact of assimilating water vaporsensitive satellite infrared brightness temperatures and Doppler radar reflectivity and radial velocity observations on the analysis accuracy of a ...

Thomas A. Jones; Jason A. Otkin; David J. Stensrud; Kent Knopfmeier

2013-10-01T23:59:59.000Z

162

A Quantitative Aerosol Generator Designed for Particulate Matter (PM) Continuous Emissions Monitoring Systems (CEMS) Calibration  

Science Conference Proceedings (OSTI)

A growing number of utilities are required to continuously monitor particulate matter (PM) emissions using continuous emissions monitoring systems (CEMS). Currently, simultaneous EPA manual reference method tests (EPA Reference Method 5) must be used to calibrate and audit these PM CEMS following EPA Performance Specification 11 guidelines (PS-11). These calibrations are not only difficult, time consuming, and expensive to perform, but are particularly onerous because they require the utility to modify p...

2009-12-22T23:59:59.000Z

163

Desert dust and anthropogenic aerosol interactions in the Community Climate System Model coupled-carbon-climate model  

Science Conference Proceedings (OSTI)

Coupled-carbon-climate simulations are an essential tool for predicting the impact of human activity onto the climate and biogeochemistry. Here we incorporate prognostic desert dust and anthropogenic aerosols into the CCSM3.1 coupled carbon-climate model and explore the resulting interactions with climate and biogeochemical dynamics through a series of transient anthropogenic simulations (20th and 21st centuries) and sensitivity studies. The inclusion of prognostic aerosols into this model has a small net global cooling effect on climate but does not significantly impact the globally averaged carbon cycle; we argue that this is likely to be because the CCSM3.1 model has a small climate feedback onto the carbon cycle. We propose a mechanism for including desert dust and anthropogenic aerosols into a simple carbon-climate feedback analysis to explain the results of our and previous studies. Inclusion of aerosols has statistically significant impacts on regional climate and biogeochemistry, in particular through the effects on the ocean nitrogen cycle and primary productivity of altered iron inputs from desert dust deposition.

Mahowald, Natalie [Cornell University; Rothenberg, D. [Cornell University; Lindsay, Keith [National Center for Atmospheric Research (NCAR); Doney, Scott C. [Woods Hole Oceanographic Institution; Moore, Jefferson Keith [University of California, Irvine; Randerson, James T. [University of California, Irvine; Thornton, Peter E [ORNL; Jones, C. D. [Hadley Center, Devon, England

2011-02-01T23:59:59.000Z

164

Investigation of the optical and cloud forming properties of pollution, biomass burning, and mineral dust aerosols  

E-Print Network (OSTI)

This dissertation describes the use of measured aerosol size distributions and size-resolved hygroscopic growth to examine the physical and chemical properties of several particle classes. The primary objective of this work was to investigate the optical and cloud forming properties of a range of ambient aerosol types measured in a number of different locations. The tool used for most of these analyses is a differential mobility analyzer / tandem differential mobility analyzer (DMA / TDMA) system developed in our research group. To collect the data described in two of the chapters of this dissertation, an aircraft-based version of the DMA / TDMA was deployed to Japan and California. The data described in two other chapters were conveniently collected during a period when the aerosol of interest came to us. The unique aspect of this analysis is the use of these data to isolate the size distributions of distinct aerosol types in order to quantify their optical and cloud forming properties. I used collected data during the Asian Aerosol Characterization Experiment (ACE-Asia) to examine the composition and homogeneity of a complex aerosol generated in the deserts and urban regions of China and other Asian countries. An aircraft-based TDMA was used for the first time during this campaign to examine the size-resolved hygroscopic properties of the aerosol. The Asian Dust Above Monterey (ADAM-2003) study was designed both to evaluate the degree to which models can predict the long-range transport of Asian dust, and to examine the physical and optical properties of that aged dust upon reaching the California coast. Aerosol size distributions and hygroscopic growth were measured in College Station, Texas to investigate the cloud nucleating and optical properties of a biomass burning aerosol generated from fires on the Yucatan Peninsula. Measured aerosol size distributions and size-resolved hygroscopicity and volatility were used to infer critical supersaturation distributions of the distinct particle types that were observed during this period. The predicted cloud condensation nuclei concentrations were used in a cloud model to determine the impact of the different aerosol types on the expected cloud droplet concentration. RH-dependent aerosol extinction coefficients were also calculated.

Lee, Yong Seob

2003-05-01T23:59:59.000Z

165

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

Science Conference Proceedings (OSTI)

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 in AERO, compared to the MET simulation. Nevertheless, biases in some of the simulated meteorological quantities (e.g., MBL temperature and humidity) and aerosol quantities (e.g., underestimations of accumulation mode aerosol number) might affect simulated stratocumulus and energy fluxes over the Southeastern Pacific, and require further investigation. The well-simulated timing and outflow patterns of polluted and clean episodes demonstrate the model's ability to capture daily/synoptic scale variations of aerosol and cloud properties, and suggest that the model is suitable for studying atmospheric processes associated with pollution outflow over the ocean. The overall performance of the regional model in simulating mesoscale clouds and boundary layer properties is encouraging and suggests that reproducing gradients of aerosol and cloud droplet concentrations and coupling cloud-aerosol-radiation processes are important when simulating marine stratocumulus over the Southeast Pacific.

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

2011-12-02T23:59:59.000Z

166

Polarimetric Remote Sensing of Aerosols over Land  

Science Conference Proceedings (OSTI)

The sensitivity of accurate polarized reflectance measurements over a broad spectral (410 -2250 nm) and angular (60 from nadir) range to the presence of aerosols over land is analyzed and the consequent ability to retrieve the aerosol burden and microphysical model is assessed. Here we present a new approach to the correction of polarization observations for the effects of the surface that uses longer wavelength observations to provide a direct estimate of the surface polarized reflectance. This approach to surface modeling is incorporated into an optimal estimation framework for retrieving the particle number density and a detailed aerosol microphysical model: effective radius, effective variance and complex refractive index of aerosols. A sensitivity analysis shows that the uncertainties in aerosol optical thickness (AOT) increase with AOT while the uncertainties in the microphysical model decrease. Of particular note is that the uncertainty in the single scattering albedo is less than 0.05 by the time the AOT is greater than 0.2. We also find that calibration is the major source of uncertainty and that perfect angular and spectral correlation of calibration errors reduces the uncertainties in retrieved quantities compared with the case of uncorrelated errors. Finally, in terms of required spectral range, we observe that shorter wavelength (aerosols from polarized reflectance observations. The optimal estimation scheme is then tested on observations made by the Research Scanning Polarimeter during the Aerosol Lidar Validation experiment and over Southern California wild fires. These two sets of observations test the retrieval scheme under pristine and polluted conditions respectively. In both cases we find that the retrievals are within the combined uncertainties of the retrieval and the Aerosol Robotic Network Cimel products and Total Ozone Mapping Spectrometer Aerosol Index that we are comparing to. This confirms the validity of the sensitivity analysis of the polarized reflectance observations to the aerosol number density and microphysical model and demonstrates the unique capability to accurately retrieve aerosol optical depths under pristine conditions and also the single scattering albedo of aerosols at higher optical depths.

Waquet, F.; Cairns, Brian; Knobelspiesse, Kirk D.; Chowdhary, J.; Travis, Larry D.; Schmid, Beat; Mishchenko, M.

2009-01-26T23:59:59.000Z

167

Spatial and temporal variations of aerosols around Beijing in summer 2006: 2. Local and column aerosol optical properties  

SciTech Connect

Weather Research and Forecasting (WRF)-chem model calculations were conducted to study aerosol optical properties around Beijing, China, during the Campaign of Air Quality Research in Beijing and Surrounding Region 2006 (CAREBeijing-2006) period. In this paper, we interpret aerosol optical properties in terms of aerosol mass concentrations and their chemical compositions by linking model calculations with measurements. In general, model calculations reproduced observed features of spatial and temporal variations of various surface and column aerosol optical parameters in and around Beijing. Spatial and temporal variations of aerosol absorption, scattering, and extinction coefficient corresponded well to those of elemental carbon (primary aerosol), sulfate (secondary aerosol), and the total aerosol mass concentration, respectively. These results show that spatial and temporal variations of the absorption coefficient are controlled by local emissions (within 100 km around Beijing during the preceding 24 h), while those of the scattering coefficient are controlled by regional-scale emissions (within 500 km around Beijing during the preceding 3 days) under synoptic-scale meteorological conditions, as discussed in our previous study of aerosol mass concentration. Vertical profiles of aerosol extinction revealed that the contribution of secondary aerosols and their water uptake increased with altitude within the planetary boundary layer, leading to a considerable increase in column aerosol optical depth (AOD) around Beijing. These effects are the main factors causing differences in regional and temporal variations between particulate matter (PM) mass concentration at the surface and column AOD over a wide region in the northern part of the Great North China Plain.

Matsui, Hitoshi; Koike, Makoto; Kondo, Yutaka; Takegawa, Nobuyuki; Fast, Jerome D.; Poschl, U.; Garland, R. M.; Andreae, M. O.; Wiedensohler, A.; Sugimoto, N.; Zhu, T.

2010-11-23T23:59:59.000Z

168

Solid aerosol generator  

DOE Patents (OSTI)

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.

Prescott, Donald S. (Shelley, ID); Schober, Robert K. (Midwest City, OK); Beller, John (Idaho Falls, ID)

1992-01-01T23:59:59.000Z

169

Black carbon aerosols and the third polar ice cap  

SciTech Connect

Recent thinning of glaciers over the Himalayas (sometimes referred to as the third polar region) have raised concern on future water supplies since these glaciers supply water to large river systems that support millions of people inhabiting the surrounding areas. Black carbon (BC) aerosols, released from incomplete combustion, have been increasingly implicated as causing large changes in the hydrology and radiative forcing over Asia and its deposition on snow is thought to increase snow melt. In India BC emissions from biofuel combustion is highly prevalent and compared to other regions, BC aerosol amounts are high. Here, we quantify the impact of BC aerosols on snow cover and precipitation from 1990 to 2010 over the Indian subcontinental region using two different BC emission inventories. New estimates indicate that Indian BC emissions from coal and biofuel are large and transport is expected to expand rapidly in coming years. We show that over the Himalayas, from 1990 to 2000, simulated snow/ice cover decreases by {approx}0.9% due to aerosols. The contribution of the enhanced Indian BC to this decline is {approx}36%, similar to that simulated for 2000 to 2010. Spatial patterns of modeled changes in snow cover and precipitation are similar to observations (from 1990 to 2000), and are mainly obtained with the newer BC estimates.

Menon, Surabi; Koch, Dorothy; Beig, Gufran; Sahu, Saroj; Fasullo, John; Orlikowski, Daniel

2010-04-15T23:59:59.000Z

170

Numerical Study of an Observed Orogenic Mesoscale Convective System. Part 1: Simulated Genesis and Comparison with Observations  

Science Conference Proceedings (OSTI)

The interaction of topographically induced thermally and mechanically driven diurnal flow regimes in the lee of the Rockies is shown to lead to the growth of a mesoscale convective system (MCS). An organic MCS observed during the 1977 combined ...

Gregory J. Tripoli; William R. Cotton

1989-02-01T23:59:59.000Z

171

Aerosol Duct Sealing : Technologies : From the Lab to the Marketplace...  

NLE Websites -- All DOE Office Websites (Extended Search)

the California building code changes and increasing availability of the aerosol sealing technology, more homeowners and facilities managers will seal their duct systems and save...

172

FY 2011 Second Quarter: Demonstration of New Aerosol Measurement Verification Testbed for Present-Day Global Aerosol Simulations  

SciTech Connect

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).

Koch, D

2011-03-20T23:59:59.000Z

173

East Asian Studies of Tropospheric Aerosols and their Impact on Regional Climate (EAST-AIRC): An Overview  

Science Conference Proceedings (OSTI)

As the most populated region of the world, Asia is a major source of aerosols with potential large impact over vast downstream areas. Papers published in this special section describe the variety of aerosols observed in China and their effects and interactions with the regional climate as part of the East Asian Study of Tropospheric Aerosols and Impact on Regional Climate (EAST-AIRC). The majority of the papers are based on analyses of observations made under three field projects, namely, the Atmospheric Radiation Measurements (ARM) Mobile Facility mission in China (AMF10 China), the East Asian Study of Tropospheric Aerosols: an International Regional Experiment (EAST-AIRE), and the Atmospheric Aerosols of China and their Climate Effects (AACCE). The former two are US-China collaborative projects and the latter is a part of the Chinas National Basic Research program (or often referred to as 973 project). Routine meteorological data of China are also employed in some studies. The wealth of general and specialized measurements lead to extensive and close-up investigations of the optical, physical and chemical properties of anthropogenic, natural, and mixed aerosols; their sources, formation and transport mechanisms; horizontal, vertical and temporal variations; direct and indirect effects and interactions with the East Asian monsoon system. Particular efforts are made to advance our understanding of the mixing and interaction between dust and anthropogenic pollutants during transport. Several modeling studies were carried out to simulate aerosol impact on radiation budget, temperature, precipitation, wind and atmospheric circulation, fog, etc. In addition, impacts of the Asian monsoon system on aerosol loading are also simulated.

Li, Zhanqing; Li, C.; Chen, H.; Tsay, S. C.; Holben, B. N.; Huang, J.; Li, B.; Maring, H.; Qian, Yun; Shi, Guangyu; Xia, X.; Yin, Y.; Zheng, Y.; Zhuang, G.

2011-02-01T23:59:59.000Z

174

Observational Analysis of the Predictability of Mesoscale Convective Systems  

Science Conference Proceedings (OSTI)

Mesoscale convective systems (MCSs) have a large influence on the weather over the central United States during the warm season by generating essential rainfall and severe weather. To gain insight into the predictability of these systems, the ...

Israel L. Jirak; William R. Cotton

2007-08-01T23:59:59.000Z

175

Evaluating WRF-Chem aerosol indirect effects in Southeast Pacific marine stratocumulus during VOCALS-REx  

SciTech Connect

We evaluate a regional-scale simulation with the WRF-Chem model for the VAMOS (Variability of the American Monsoon Systems) Ocean-Cloud-Atmosphere-Land Study Regional Experiment (VOCALS-REx), which sampled the Southeast Pacific's persistent stratocumulus deck. Evaluation of VOCALS-REx ship-based and three aircraft observations focuses on analyzing how aerosol loading affects marine boundary layer (MBL) dynamics and cloud microphysics. We compare local time series and campaign-averaged longitudinal gradients, and highlight differences in model simulations with (W) and without (NW) wet deposition processes. The higher aerosol loadings in the NW case produce considerable changes in MBL dynamics and cloud microphysics, in accordance with the established conceptual model of aerosol indirect effects. These include increase in cloud albedo, increase in MBL and cloud heights, drizzle suppression, increase in liquid water content, and increase in cloud lifetime. Moreover, better statistical representation of aerosol mass and number concentration improves model fidelity in reproducing observed spatial and temporal variability in cloud properties, including top and base height, droplet concentration, water content, rain rate, optical depth (COD) and liquid water path (LWP). Together, these help to quantify confidence in WRF-Chem's modeled aerosol-cloud interactions, especially in the activation parameterization, while identifying structural and parametric uncertainties including: irreversibility in rain wet removal; overestimation of marine DMS and sea salt emissions, and accelerated aqueous sulfate conversion. Our findings suggest that WRF-Chem simulates marine cloud-aerosol interactions at a level sufficient for applications in forecasting weather and air quality and studying aerosol climate forcing, and may do so with the reliability required for policy analysis.

Saide P. E.; Springston S.; Spak, S. N.; Carmichael, G. R.; Mena-Carrasco, M. A.; Yang, Q.; Howell, S.; Leon, D. C.; Snider, J. R.; Bandy, A. R.; Collett, J. L.; Benedict, K. B.; deSzoeke, S. P.; Hawkins, L. N.; Allen, G.; Crawford, I.; Crosier, J.

2012-03-29T23:59:59.000Z

176

Evaluating WRF-Chem aerosol indirect effects in Southeast Pacific marine stratocumulus during VOCALS-REx  

SciTech Connect

We evaluate a regional-scale simulation with the WRF-Chem model for the VAMOS (Variability of the American Monsoon Systems) Ocean-Cloud-Atmosphere-Land Study Regional Experiment (VOCALS-REx), which sampled the Southeast Pacific's persistent stratocumulus deck. Evaluation of VOCALS-REx ship-based and aircraft observations focuses on analyzing how aerosol loading affects marine boundary layer (MBL) dynamics and cloud microphysics. We compare local time series and campaign averaged longitudinal gradients, and highlight differences in model simulations with (W) and without wet (NW) deposition processes. The higher aerosol loadings in the NW case produce considerable changes in MBL dynamics and cloud microphysics, in accordance with the established conceptual model of aerosol indirect effects. These include increase in cloud albedo, increase in MBL and cloud heights, drizzle suppression, increase in liquid water content, and increase in cloud lifetime. Moreover, better statistical representation of aerosol mass and number concentration improves model fidelity in reproducing observed spatial and temporal variability in cloud properties, including top and base height, droplet concentration, water content, rain rate, optical depth (COD) and liquid water path (LWP). Together, these help to quantify confidence in WRF-Chem's modeled aerosol-cloud interactions, while identifying structural and parametric uncertainties including: irreversibility in rain wet removal; overestimation of marine DMS and sea salt emissions and accelerated aqueous sulfate conversion. Our findings suggest that WRF-Chem simulates marine cloud-aerosol interactions at a level sufficient for applications in forecasting weather and air quality and studying aerosol climate forcing, including the reliability required for policy analysis and geo-engineering applications.

Saide, Pablo; Spak, S. N.; Carmichael, Gregory; Mena-Carrasco, M. A.; Yang, Qing; Howell, S. G.; Leon, Dolislager; Snider, Jefferson R.; Bandy, Alan R.; Collett, Jeffrey L.; Benedict, K. B.; de Szoeke, S.; Hawkins, Lisa; Allen, Grant; Crawford, I.; Crosier, J.; Springston, S. R.

2012-03-30T23:59:59.000Z

177

Observing industrial control system attacks launched via metasploit framework  

Science Conference Proceedings (OSTI)

Industrial Control Systems (ICS) are present across many industries ranging from automotive to utilities. These systems have been found to be connected to corporate enterprise servers and can communicate over unencrypted communication channels. Interconnections ... Keywords: SCADA, industrial control systems, intrusion detection

Nathan Wallace, Travis Atkison

2013-04-01T23:59:59.000Z

178

Parameter exploration of optically trapped liquid aerosols  

E-Print Network (OSTI)

When studying the motion of optically trapped particles on the $\\mu s$ time scale, in low viscous media such as air, inertia cannot be neglected. Resolution of unusual and interesting behaviour not seen in colloidal trapping experiments is possible. In attempt to explain the phenomena we use power spectral methods to perform a parameter study of the Brownian motion of optically trapped liquid aerosol droplets concentrated around the critically damped regime. We present evidence that the system is suitably described by a simple harmonic oscillator model which must include a description of Fax\\'{e}n's correction, but not necessarily frequency dependent hydrodynamic corrections to Stokes' law. We also provide results describing how the system behaves under several variables and discuss the difficulty in decoupling the parameters responsible for the observed behaviour. We show that due to the relatively low dynamic viscosity and high trap stiffness it is easy to transfer between over- and under-damped motion by experimentally altering either trap stiffness or damping. Our results suggest stable aerosol trapping may be achieved in under-damped conditions, but the onset of deleterious optical forces at high trapping powers prevents the probing of the upper stability limits due to Brownian motion.

D. R. Burnham; P. J. Reece; D. McGloin

2009-07-27T23:59:59.000Z

179

Size Distribution of Coastal Aerosols: Effects of Local Sources and Sinks  

Science Conference Proceedings (OSTI)

Using aerosol optical depth as a function of wavelength obtained from ground-based multiwavelength radiometer observations, columnar size-distribution functions of aerosols have been derived. It has been found that the nature of the derived size-...

K. Krishna Moorthy; Prabha R. Nair; B. V. Krishna Murthy

1991-06-01T23:59:59.000Z

180

A Multisensor Perspective on the Radiative Impacts of Clouds and Aerosols  

Science Conference Proceedings (OSTI)

The launch of CloudSat and CloudAerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) in 2006 provided the first opportunity to incorporate information about the vertical distribution of cloud and aerosols directly into global ...

David S. Henderson; Tristan LEcuyer; Graeme Stephens; Phil Partain; Miho Sekiguchi

2013-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol observing systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

The Evolution of the Physicochemical Properties of Aerosols in the Atmosphere  

E-Print Network (OSTI)

A Differential Mobility Analyzer/Tandem Differential Mobility Analyzer (DMA/TDMA) system was used to measure simultaneously the size distribution and hygroscopicity of the ambient aerosol population. The system was operated aboard the National Center for Atmospheric Research/National Science Foundation (NCAR/NSF) C-130 during the 2006 Megacity Initiative: Local and Global Research Observations (MILAGRO) field campaign followed by the 2006 Intercontinental Chemical Transport Experiment Phase B (INTEX-B) field campaign. The research flights for the MILAGRO campaign were conducted within the Mexico City basin and the region to the northeast within the pollution plume. The aerosol within the basin is dominated by organics with an average measured kappa value of 0.21 /- 0.18, 0.13 /- 0.09, 0.09 /- 0.06, 0.14 /- 0.07, and 0.17 /- 0.04 for dry particle diameters of 0.025, 0.050, 0.100, 0.200, and 0.300 mu m, respectively. As the aerosols are transported away from the Mexico City Basin, secondary organic aerosol formation through oxidation and condensation of sulfate on the aerosols surface rapidly increases the solubility of the aerosol. The most pronounced change occurs for a 0.100 mu m diameter aerosol where, after 6 hours of transport, the average kappa value increased by a factor of 3 to a kappa?of 0.29 /- 0.13. The rapid increase in solubility increases the fraction of the aerosol size distribution that could be activated within a cloud. The research flights for the INTEX-B field campaign investigated the evolution of the physicochemical properties of the Asian aerosol plume after 3 to 7 days of transport. The Asian aerosol within the free troposphere exhibited a bimodal growth distribution roughly 50 percent of the time. The more soluble mode of the growth distribution contributed between 67-80 percent of the overall growth distribution and had an average kappa?between 0.40 and 0.53 for dry particle diameters of 0.025, 0.050, 0.100, and 0.300 mu m. The secondary mode was insoluble with an average kappa?between 0.01 and 0.05 for all dry particle diameters. Cloud condensation nuclei closure was attained at a supersaturation of 0.2 percent for all particles within the free troposphere by either assuming a pure ammonium bisulfate composition or a binary composition of ammonium bisulfate and an insoluble organic.

Tomlinson, Jason

2010-12-01T23:59:59.000Z

182

Combined System for Observations of Tropospheric and Stratospheric Thin Clouds  

Science Conference Proceedings (OSTI)

A balloonborne sonde and a polarization lidar have been developed to make combined observations of thin tropospheric and stratospheric clouds. In their first application these instruments have been used in a campaign organized to study Antarctic ...

A. Adriani; G. P. Gobbi; M. Viterbini; S. Ugazio

1993-02-01T23:59:59.000Z

183

Aerosols in Central California: Unexpectedly Large Contribution of Coarse Mode to Aerosol Radiative Forcing  

Science Conference Proceedings (OSTI)

The majority of previous studies dealing with effect of coarse-mode aerosols on the radiation budget have focused primary on polluted regions with substantial aerosol loadings. We reexamine this effect for a relatively "pristine" area using a unique 1-month dataset collected during recent Carbonaceous Aerosol and Radiative Effects Study (CARES). We demonstrate that the coarse-mode (supermicron) particles can contribute substantially (more than 50%) and frequently (up to 85% of time) to the total volume. In contrast to the conventional expectations that the radiative impact of coarse-mode aerosols should be small for "pristine" regions, we find that the neglecting of the large particles may lead to significant overestimation (up to 45%) of direct aerosol radiative forcing at the top-of atmosphere despite of very small aerosol optical depth (about 0.05 at 0.5 ). Our findings highlight the potential for widespread impacts of the coarse-mode aerosols on the pristine radiative properties over land and the need for more explicit inclusion of the coarse-mode aerosols in climate-related observational and model studies.

Kassianov, Evgueni I.; Pekour, Mikhail S.; Barnard, James C.

2012-10-20T23:59:59.000Z

184

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

Science Conference Proceedings (OSTI)

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.

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

2011-07-06T23:59:59.000Z

185

Attachment of radon progeny to cigarette-smoke aerosols  

SciTech Connect

The daughter products of radon gas are now recognized as a significant contributor to radiation exposure to the general public. It is also suspected that a synergistic effect exists with the combination cigarette smoking and radon exposure. We have conducted an experimental investigation to determine the physical nature of radon progeny interactions with cigarette smoke aerosols. The size distributions of the aerosols are characterized and attachment rates of radon progeny to cigarette-smoke aerosols are determined. Both the mainstream and sidestream portions of the smoke aerosol are investigated. Unattached radon progeny are very mobile and, in the presence of aerosols, readily attach to the particle surfaces. In this study, an aerosol chamber is used to contain the radon gas, progeny and aerosol mixture while allowing the attachment process to occur. The rate of attachment is dependent on the size distribution, or diffusion coefficient, of the radon progeny as well as the aerosol size distribution. The size distribution of the radon daughter products is monitored using a graded-screen diffusion battery. The diffusion battery also enables separation of the unattached radon progeny from those attached to the aerosol particles. Analysis of the radon decay products is accomplished using alpha spectrometry. The aerosols of interest are size fractionated with the aid of a differential mobility analyzer and cascade impactor. The measured attachment rates of progeny to the cigarette smoke are compared to those found in similar experiments using an ambient aerosol. The lowest attachment coefficients observed, {approximately}10{sup {minus}6} cm{sup 3}/s, occurred for the ambient aerosol. The sidestream and mainstream smoke aerosols exhibited higher attachment rates in that order. The results compared favorably with theories describing the coagulation process of aerosols.

Biermann, A.H.; Sawyer, S.R.

1995-05-01T23:59:59.000Z

186

ARM - Field Campaign - 2007 Cumulus Humilis Aerosol Process Study (CHAPS)  

NLE Websites -- All DOE Office Websites (Extended Search)

7 Cumulus Humilis Aerosol Process Study (CHAPS) 7 Cumulus Humilis Aerosol Process Study (CHAPS) Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : 2007 Cumulus Humilis Aerosol Process Study (CHAPS) 2007.06.04 - 2007.06.25 Lead Scientist : Carl Berkowitz For data sets, see below. Description The primary goal of this campaign was to characterize and contrast freshly emitted aerosols above, within and below fields of cumulus humilis (or fair-weather cumulus, FWC) and to use these observations to address how below-cloud and above-cloud aerosol optical and cloud nucleating properties differ downwind of a mid-size city relative to similar aerosols in air less affected by emissions. The observations from this campaign can also be used to aid in the development and evaluation of parameterizations of the

187

Observations On European Advanced Traveler Information And Traffic Management Systems  

E-Print Network (OSTI)

Road Transport Informatics (RTI). There were four areas ofstudy road safety through RTI and to define functionalrequirements for the relevant RTI systems (14 projects); 3)

Yim, Youngbin; Ygnace, Jean-luc

1993-01-01T23:59:59.000Z

188

he Impact of Primary Marine Aerosol on Atmospheric Chemistry, Radiation and Climate: A CCSM Model Development Study  

SciTech Connect

This project examined the potential large-scale influence of marine aerosol cycling on atmospheric chemistry, physics and radiative transfer. Measurements indicate that the size-dependent generation of marine aerosols by wind waves at the ocean surface and the subsequent production and cycling of halogen-radicals are important but poorly constrained processes that influence climate regionally and globally. A reliable capacity to examine the role of marine aerosol in the global-scale atmospheric system requires that the important size-resolved chemical processes be treated explicitly. But the treatment of multiphase chemistry across the breadth of chemical scenarios encountered throughout the atmosphere is sensitive to the initial conditions and the precision of the solution method. This study examined this sensitivity, constrained it using high-resolution laboratory and field measurements, and deployed it in a coupled chemical-microphysical 3-D atmosphere model. First, laboratory measurements of fresh, unreacted marine aerosol were used to formulate a sea-state based marine aerosol source parameterization that captured the initial organic, inorganic, and physical conditions of the aerosol population. Second, a multiphase chemical mechanism, solved using the Max Planck Institute for Chemistry??s MECCA (Module Efficiently Calculating the Chemistry of the Atmosphere) system, was benchmarked across a broad set of observed chemical and physical conditions in the marine atmosphere. Using these results, the mechanism was systematically reduced to maximize computational speed. Finally, the mechanism was coupled to the 3-mode modal aerosol version of the NCAR Community Atmosphere Model (CAM v3.6.33). Decadal-scale simulations with CAM v.3.6.33, were run both with and without reactive-halogen chemistry and with and without explicit treatment of particulate organic carbon in the marine aerosol source function. Simulated results were interpreted (1) to evaluate influences of 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.

Keene, William C. [University of Virginia] [University of Virginia; Long, Michael S. [University of Virginia] [University of Virginia

2013-05-20T23:59:59.000Z

189

Estimation of WECC System Inertia Using Observed Frequency Transients  

SciTech Connect

As demand for electricity in the western United States increases, stresses upon the aging power grid are intensifying. Computer models based on complex mathematical relationships are being developed to assist in understanding the impact of deregulation and market transformation. Frequency, load, and plant outage events data collected over the last several years. Analysis of these events was performed to determine frequency deviation and the systems inertial constant (M) during each event. Utilizing a theoretical relationship that relates system inertia to power loss, M was calculated for 157 events. The relationship of M to system wide load was then examined.

Chassin, David P.; Huang, Zhenyu; Donnelly, Matt K.; Hassler, Candee A.; Ramirez, Enrique; Ray, Cody W.

2005-04-19T23:59:59.000Z

190

An Observational Study of Derecho-Producing Convective Systems  

Science Conference Proceedings (OSTI)

This study identifies the common large-scale environments associated with the development of derecho- producing convective systems (DCSs) from a large number of events. Patterns are identified using statistical clustering of the 500-mb ...

Michael C. Coniglio; David J. Stensrud; Michael B. Richman

2004-04-01T23:59:59.000Z

191

Carbonaceous Aerosols and Radiative...  

NLE Websites -- All DOE Office Websites (Extended Search)

Aerosols and Radiative Effects Study Science Objective This field campaign is designed to increase scientific knowledge about the evolution of black carbon, primary organic...

192

Computational simulation of aerosol behaviour.  

E-Print Network (OSTI)

??In this thesis, computational methods have been developed for the simulation of aerosol dynamics and transport. Two different coupled aerosol-computational fluid dynamics (CFD) models are (more)

Pyyknen, Jouni

2002-01-01T23:59:59.000Z

193

Radially Classified Aerosol Detector for Aircraft-Based Submicron Aerosol Measurements  

Science Conference Proceedings (OSTI)

A radially classified aerosol detector (RCAD) for fast characterization of fine particle size distributions aboard aircraft has been designed and implemented. The measurement system includes a radial differential mobility analyzer and a high-flow,...

Lynn M. Russell; Shou-Hua Zhang; Richard C. Flagan; John H. Seinfeld; Mark R. Stolzenburg; Robert Caldow

1996-06-01T23:59:59.000Z

194

An Observing System Experiment with the West Coast Picket Fence  

Science Conference Proceedings (OSTI)

Analyses and forecasts from a modern data assimilation and modeling system are used to evaluate the impact of a special rawinsonde dataset of 3-h soundings at seven sites interspersed with the seven regular sites along the West Coast (to form a ...

Paul A. Hirschberg; Perry C. Shafran; Russell L. Elsberry; Elizabeth A. Ritchie

2001-10-01T23:59:59.000Z

195

Global Two-Channel AVHRR Retrievals of Aerosol Properties over the Ocean for the Period of NOAA-9 Observations and Preliminary Retrievals Using NOAA-7 and NOAA-11 Data  

Science Conference Proceedings (OSTI)

Described is an improved algorithm that uses channel 1 and 2 radiances of the Advanced Very High Resolution Radiometer (AVHRR) to retrieve the aerosol optical thickness and ngstrm exponent over the ocean. Specifically discussed are recent ...

Igor V. Geogdzhayev; Michael I. Mishchenko; William B. Rossow; Brian Cairns; Andrew A. Lacis

2002-02-01T23:59:59.000Z

196

Two MODIS Aerosol Products over Ocean on the Terra and Aqua CERES SSF Datasets  

Science Conference Proceedings (OSTI)

Understanding the impact of aerosols on the earths radiation budget and the long-term climate record requires consistent measurements of aerosol properties and radiative fluxes. The Clouds and the Earths Radiant Energy System (CERES) Science ...

Alexander Ignatov; Patrick Minnis; Norman Loeb; Bruce Wielicki; Walter Miller; Sunny Sun-Mack; Didier Tanr; Lorraine Remer; Istvan Laszlo; Erika Geier

2005-04-01T23:59:59.000Z

197

Aerosol Effects of the Condensation Process on a Convective Cloud Simulation  

Science Conference Proceedings (OSTI)

Using a nonhydrostatic model with a double-moment bulk cloud microphysics scheme, we introduce an aerosol effect on a convective cloud system by accelerating the condensation and evaporation processes (the aerosol condensational effect). To ...

Tatsuya Seiki; Teruyuki Nakajima

198

Developments in the CSU-RAMS Aerosol Model: Emissions, Nucleation, Regeneration, Deposition, and Radiation  

Science Conference Proceedings (OSTI)

The Colorado State University Regional Atmospheric Modeling System (RAMS) has undergone development focused upon improving the treatment of aerosols in the microphysics model, with the goal of examining the impacts of aerosol characteristics, ...

Stephen M. Saleeby; Susan C. Van Den Heever

199

Recent activities in the Aerosol Generation and Transport Program  

SciTech Connect

General statements may be made on the behavior of single-component and multi-component aerosols in the Nuclear Safety Pilot Plant vessel. The removal processes for U/sub 3/O/sub 8/, Fe/sub 2/O/sub 3/, and U/sub 3/O/sub 8/ + Fe/sub 2/O/sub 3/ aerosols are enhanced in a steam-air atmosphere. Steam-air seems to have little effect on removal of concrete aerosol from the vessel atmosphere. A steam-air environment causes a change in aerosol shape from chain-agglomerate to basically spherical for U/sub 3/O/sub 8/, Fe/sub 2/O/sub 3/, and U/sub 3/O/sub 8/ + Fe/sub 2/O/sub 3/ aerosol; for concrete the change in aerosol shape is from chain-agglomerate to partially spherical. The mass ratio of the individual components of a multi-component aerosol seems to have an observable influence on the resultant behavior of these aerosols in steam. The enhanced rate of removal of the U/sub 3/O/sub 8/, the Fe/sub 2/O/sub 3/, and the mixed U/sub 3/O/sub 8/ + Fe/sub 2/O/sub 3/ aerosols from the atmosphere of the NSPP vessel by steam-air is probably caused by the change in aerosol shape and the condensation of steam on the aerosol surfaces combining to increase the effect of gravitational settling. The apparent lack of an effect by steam-air on the removal rate of concrete aerosol could result from a differing physical/chemical response of the surfaces of this aerosol to condensing steam.

Adams, R.E.

1984-01-01T23:59:59.000Z

200

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

NLE Websites -- All DOE Office Websites (Extended Search)

govCampaignsBiogenic Aerosols - Effects on Clouds and Climate: govCampaignsBiogenic Aerosols - Effects on Clouds and Climate: FIGAERO-ToF-CIMS Instrument in Hyytiala with AMF-2 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: FIGAERO-ToF-CIMS Instrument in Hyytiala with AMF-2 2014.04.01 - 2014.06.01 Lead Scientist : Joel Thornton Description The ultimate goal of this work is to connect field and laboratory observations of organic aerosol chemical and physical properties during the nascent growth stage to the diurnal and vertical distributions of aerosol abundance measured over the boreal forest by the ARM Mobile Facility 2

Note: This page contains sample records for the topic "aerosol observing systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Ganges valley aerosol experiment.  

Science Conference Proceedings (OSTI)

In June 2011, the Ganges Valley Aerosol Experiment (GVAX) began in the Ganges Valley region of India. The objective of this field campaign is to obtain measurements of clouds, precipitation, and complex aerosols to study their impact on cloud formation and monsoon activity in the region.

Kotamarthi, V.R.; Satheesh, S.K. (Environmental Science Division); (Indian Institute of Science, Bangalore, India)

2011-08-01T23:59:59.000Z

202

Toward a Minimal Representation of Aerosols in Climate Models: Description and Evaluation in the Community Atmosphere Model CAM5  

Science Conference Proceedings (OSTI)

A modal aerosol module (MAM) has been developed for the Community Atmosphere Model version 5 (CAM5), the atmospheric component of the Community Earth System Model version 1 (CESM1). MAM is capable of simulating the aerosol size distribution and both internal and external mixing between aerosol components, treating numerous complicated aerosol processes and aerosol physical, chemical and optical properties in a physically based manner. Two MAM versions were developed: a more complete version with seven-lognormal modes (MAM7), and a three-lognormal mode version (MAM3) for the purpose of long-term (decades to centuries) simulations. Major approximations in MAM3 include assuming immediate mixing of primary organic matter (POM) and black carbon (BC) with other aerosol components, merging of the MAM7 fine dust and fine sea salt modes into the accumulation mode, merging of the MAM7 coarse dust and coarse sea salt modes into the single coarse mode, and neglecting the explicit treatment of ammonia and ammonium cycles. Simulated sulfate and secondary organic aerosol (SOA) mass concentrations are remarkably similar between MAM3 and MAM7 as most ({approx}90%) of these aerosol species are in the accumulation mode. Differences of POM and BC concentrations between MAM3 and MAM7 are also small (mostly within 10%) because of the assumed hygroscopic nature of POM, so that freshly emitted POM and BC are wet-removed before mixing internally with soluble aerosol species. Sensitivity tests with the POM assumed to be hydrophobic and with slower aging process increase the POM and BC concentrations, especially at high latitudes (by several times). The mineral dust global burden differs by 10% and sea salt burden by 30-40% between MAM3 and MAM7 mainly due to the different size ranges for dust and sea salt modes and different standard deviations of log-normal size distribution for sea salt modes between MAM3 and MAM7. The model is able to qualitatively capture the observed geographical and temporal variations of aerosol mass and number concentrations, size distributions, and aerosol optical properties. However, there are noticeable biases, e.g., simulated sulfate and mineral dust concentrations at surface over the oceans are too low. Simulated BC concentrations are significant low in the Arctic. There is a low bias in modeled aerosol optical depth on the global scale, especially in the developing counties. There biases in aerosol simulations clearly indicate the need for improvements of aerosol processes (e.g., emission fluxes of anthropogenic aerosols and precursor gases in developing countries, boundary layer nucleation) and properties (e.g., primary aerosol emission size, POM hygroscopicity). In addition the critical role of cloud properties (e.g., liquid water content, cloud fraction) responsible for the wet scavenging of aerosol is highlighted.

Liu, Xiaohong; Easter, Richard C.; Ghan, Steven J.; Zaveri, Rahul A.; Rasch, Philip J.; Shi, Xiangjun; Lamarque, J.-F.; Gettelman, A.; Morrison, H.; Vitt, Francis; Conley, Andrew; Park, S.; Neale, Richard; Hannay, Cecile; Ekman, A. M.; Hess, Peter; Mahowald, N.; Collins, William D.; Iacono, Michael J.; Bretherton, Christopher S.; Flanner, M. G.; Mitchell, David

2012-05-21T23:59:59.000Z

203

Cloud Scavenging Effects on Aerosol Radiative and Cloud-nucleating Properties - Final Technical Report  

Science Conference Proceedings (OSTI)

The optical properties of aerosol particles are the controlling factors in determining direct aerosol radiative forcing. These optical properties depend on the chemical composition and size distribution of the aerosol particles, which can change due to various processes during the particles lifetime in the atmosphere. Over the course of this project we have studied how cloud processing of atmospheric aerosol changes the aerosol optical properties. A counterflow virtual impactor was used to separate cloud drops from interstitial aerosol and parallel aerosol systems were used to measure the optical properties of the interstitial and cloud-scavenged aerosol. Specifically, aerosol light scattering, back-scattering and absorption were measured and used to derive radiatively significant parameters such as aerosol single scattering albedo and backscatter fraction for cloud-scavenged and interstitial aerosol. This data allows us to demonstrate that the radiative properties of cloud-processed aerosol can be quite different than pre-cloud aerosol. These differences can be used to improve the parameterization of aerosol forcing in climate models.

Ogren, John A.; Sheridan, Patrick S.; Andrews, Elisabeth

2009-03-05T23:59:59.000Z

204

Anthropogenic Aerosol Radiative Forcing in Asia Derived From Regional Models With Atmospheric and Aerosol Data Assimilation  

DOE Green Energy (OSTI)

A high-resolution estimate of monthly 3D aerosol solar heating rates and surface solar fluxes in Asia from 2001 to 2004 is described here. This product stems from an Asian aerosol assimilation project, in which a) the PNNL regional model bounded by the NCEP reanalyses was used to provide meteorology, b) MODIS and AERONET data were integrated for aerosol observations, c) the Iowa aerosol/chemistry model STEM-2K1 used the PNNL meteorology and assimilated aerosol observations, and d) 3D (X-Y-Z) aerosol simulations from the STEM-2K1 were used in the Scripps Monte-Carlo Aerosol Cloud Radiation (MACR) model to produce total and anthropogenic aerosol direct solar forcing for average cloudy skies. The MACR model and STEM both used the PNNL model resolution of 0.450.4 in the horizontal and of 23 layers in the troposphere. The 20012004 averaged anthropogenic all-sky aerosol forcing is ?1.3 Wm-2 (TOA), +7.3 Wm-2 (atmosphere) and ?8.6 Wm-2 (surface) averaged in Asia (60?138E & Eq. ?45N). In the absence of AERONET SSA assimilation, absorbing aerosol concentration (especially BC aerosol) is much smaller, giving ?2.3 Wm-2 (TOA), +4.5 Wm-2 (atmosphere) and ?6.8 Wm-2 (surface), averaged in Asia. In the vertical, monthly forcing is mainly concentrated below 600hPa with maxima around 800hPa. Seasonally, low-level forcing is far larger in dry season than in wet season in South Asia, whereas the wet season forcing exceeds the dry season forcing in East Asia. The anthropogenic forcing in the present study is similar to that in Chung et al.s [2005] in overall magnitude but the former offers fine-scale features and simulated vertical profiles. The interannual variability of the computed anthropogenic forcing is significant and extremely large over major emission outflow areas. In view of this, the present studys estimate is within the implicated range of the 1999 INDOEX result. However, NCAR/CCSM3s anthropogenic aerosol forcing is much smaller than the present studys estimate at the surface, and is outside of what the INDOEX findings can support.

Chung, Chul Eddy; Ramanathan, V.; Carmichael, Gregory; Kulkarni, S.; Tang, Youhua; Adhikary, Bhupesh; Leung, Lai-Yung R.; Qian, Yun

2010-07-05T23:59:59.000Z

205

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

SciTech Connect

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 to the known indirect effects (glaciation, riming and thermodynamic), new indirect effects were discovered and quantified due to responses of sedimentation, aggregation and coalescence in glaciated clouds to changing aerosol conditions. In summary, the change in horizontal extent of the glaciated clouds ('lifetime indirect effects'), especially of ice-only clouds, was seen to be of higher importance in regulating aerosol indirect effects than changes in cloud properties ('cloud albedo indirect effects').

Phillips, Vaughan T. J.

2013-10-18T23:59:59.000Z

206

Overview of the Cumulus Humilis Aerosol Processing Study.  

Science Conference Proceedings (OSTI)

Aerosols influence climate directly by scattering and absorbing radiation and indirectly through their influence on cloud microphysical and dynamical properties. The Intergovernmental Panel on Climate Change (IPCC) concluded that the global radiative forcing due to aerosols is large and in general cools the planet. But the uncertainties in these estimates are also large due to our poor understanding of many of the important processes related to aerosols and clouds. To address this uncertainty an integrated strategy for addressing issues related to aerosols and aerosol processes was proposed. Using this conceptual framework, the Cumulus Humilis Aerosol Processing Study (CHAPS) is a stage 1 activity, that is, a detailed process study. The specific focus of CHAPS was to provide concurrent observations of the chemical composition of the activated [particles that are currently serving as cloud condensation nuclei (CCN)] and nonactivated aerosols, the scattering and extinction profiles, and detailed aerosol and droplet size spectra in the vicinity of Oklahoma City, Oklahoma, during June 2007. Numerous campaigns have examined aerosol properties downwind from large pollution sources, including the Megacity Initiative: Local and Global Research Observations (MILAGRO) campaign and the two of the three Aerosol Characterization Experiments, ACE-2 and ACE-Asia. Other studies conducted near cities have examined changes in both aerosols and clouds downwind of urban areas. For example wintertime stratiform clouds associated with the urban plumes of Denver, Colorado, and Kansas City, Missouri, have a larger number concentration and smaller median volume diameter of droplets than clouds that had not been affected by the urban plume. Likewise, a decrease in precipitation in polluted regions along the Front Range of the Rocky Mountains was discovered. In a modeling study, it was found that precipitation downwind of urban areas may be influenced by changes in aerosols as well as the convergence pattern caused by the city. Recently, the New England Air Quality Study (NEAQS), and the 2004 International Consortium for Atmospheric Research on Transport and Transformation, which were conducted during the summer of 2004, examined the transport of pollutants and aerosols eastward from New England over the Atlantic Ocean. The Texas Air Quality Study/Gulf of Mexico Atmospheric Composition and Climate Study (TexAQS/GoMACCS) also looked at relationships between clouds and aerosols in polluted conditions around Houston, Texas. In contrast to these recent studies near large or very dirty cities, CHAPS was conducted near a moderately sized city that is representative of a large number of cities around the United States. CHAPS was also one of the first times that a Aerodyne aerosol mass spectrometer was used in conjunction with a counterflow virtual impactor (CVI) inlet on an aircraft. The AMS provides information on the nonrefractory (i.e., materials that are chemically and physically unstable at high temperatures) composition of aerosols, while the CVI uses a counterflow relative to the main incoming airstream to exclude small droplets and nonactivated particles from the inlet, allowing only larger cloud droplets to enter the inlet. The combination of the CVI and AMS allow the examination of the chemical composition of the dried aerosol kernel from the cloud droplets. A key objective of the U.S. Department of Energy's (DOE)'s Atmospheric Sciences Program (ASP) is to improve the understanding of aerosol radiative effects on climate. This objective encompasses not only clear sky observations but also studies relating the effects of both aerosols on clouds and clouds on aerosols - in particular, how clouds affect the chemical and optical properties of aerosols. The latter was the science driver in the design of CHAPS. The measurement strategy for CHAPS was intended to provide measurements relevant to four questions associated with the aerosol radiative forcing issues of interest to the ASP: (1) How do the below-cloud and above-cloud aerosol optical and clou

Berg, L. K.; Berkowitz, C. M.; Ogren, J. A.; Hostetler, C. A.; Ferrare, R. A.; Dubey, M.; Andrews, E.; Coulter, R. L.; Hair, J. W.; Hubbe, J. M.Lee, Y. N.; Mazzoleni, C; Olfert, J; Springston, SR; Environmental Science Division; PNNL; NOAA Earth System Research Lab.; NASA Langley Research Center; LANL; BNL; Univ.of Alberta; Univ. of Colorado

2009-11-01T23:59:59.000Z

207

ARM - Field Campaign - Observations and Modeling of the Green Ocean Amazon:  

NLE Websites -- All DOE Office Websites (Extended Search)

Size Size Resolved CCN Measurements Related Campaigns Observations and Modeling of the Green Ocean Amazon (GOAMAZON 2014) 2014.01.01, Martin, AMF Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Observations and Modeling of the Green Ocean Amazon: Size Resolved CCN Measurements 2014.01.01 - 2014.12.31 Lead Scientist : Jian Wang Description Aerosol indirect effects, which represent the impact of aerosols on climate through influencing the properties of clouds, remain one of the main uncertainties in climate predictions (IPCC, 2007). Reducing this large uncertainty requires both improved understanding and representation of aerosol properties and processes in climate models, including the cloud activation properties of aerosols. The Atmospheric System Research (ASR)

208

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

DOE Data Explorer (OSTI)

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

Rob Newsom; John Goldsmith

209

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

DOE Data Explorer (OSTI)

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

Chitra Sivaraman; Connor Flynn

210

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

SciTech Connect

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

Chitra Sivaraman; Connor Flynn

2010-12-15T23:59:59.000Z

211

Radiative and climate impacts of absorbing aerosols  

E-Print Network (OSTI)

P.M. Forster (2004), The semi-direct aerosol effect: Impactof absorbing aerosols on marine stratocumulus. Q. J .2005), Global anthropogenic aerosol direct forcing derived

Zhu, Aihua

2010-01-01T23:59:59.000Z

212

Carbonaceous Aerosol Study Using Advanced Particle Instrumentation  

E-Print Network (OSTI)

and atmospheric organic aerosol formation. Envir. Sci.of secondary organic aerosol mass fraction, Atmos. Chem.composition of ambient aerosol particles. Environ. Sci.

Qi, Li

2010-01-01T23:59:59.000Z

213

The Effect of Satellite Observing System Changes on MERRA Water and Energy Fluxes  

Science Conference Proceedings (OSTI)

Like all reanalysis efforts, the Modern Era Retrospective-Analysis for Research and Applications (MERRA) must contend with an inhomogeneous observing network. Here the effects of the two most obvious observing system epoch changes, the Advanced ...

Franklin R. Robertson; Michael G. Bosilovich; Junye Chen; Timothy L. Miller

2011-10-01T23:59:59.000Z

214

An Automated, Observations-Based System for Short-Term Prediction of Ceiling and Visibility  

Science Conference Proceedings (OSTI)

Several methods of generating very short term (06 h) probabilistic forecasts of ceiling and visibility are investigated: 1) an observations-based (OBS-based) system in which potential predictors consist of weather observations from a network of ...

Robert L. Vislocky; J. Michael Fritsch

1997-03-01T23:59:59.000Z

215

Assimilation of Infrared Radiances in the Context of Observing System Simulation Experiments  

Science Conference Proceedings (OSTI)

The Observing System Simulation Experiment (OSSE) capability developed at Environment Canada allows simulation of all observation types currently used operationally as well as future data types. Its infrastructure, based on the operational global ...

Sylvain Heilliette; Yves J. Rochon; Louis Garand; Jacek W. Kaminski

2013-04-01T23:59:59.000Z

216

Assimilation of Synthetic Tropical Cyclone Observations into the Navy Operational Global Atmospheric Prediction System  

Science Conference Proceedings (OSTI)

In June 1990, the assimilation of synthetic tropical cyclone observations into the Navy Operational Global Atmospheric Prediction System (NOGAPS) was initiated at Fleet Numerical Oceanography Center (FNOC). These observations are derived directly ...

James S. Goerss; Richard A. Jeffries

1994-12-01T23:59:59.000Z

217

Passive Microwave Observations of the Stratiform Regions of Two Tropical Oceanic Mesoscale Convective Systems  

Science Conference Proceedings (OSTI)

High-resolution passive microwave observations within the stratiform regions of two different tropical oceanic mesoscale convective systems are investigated in detail. The observations were obtained from the Advanced Microwave Precipitation ...

Gary McGaughey; Edward J. Zipser

1996-11-01T23:59:59.000Z

218

Aerosol Retrievals under Partly Cloudy Conditions: Challenges and Perspectives  

SciTech Connect

There are lots of interesting and intriguing features of aerosols near clouds many of which can be quite engaging, as well being useful and climate-related. Exploring aerosol with the aid of the remote sensing, in situ observations and numerical modeling has piqued our curiosity and led to improve insights into the nature of aerosol and clouds and their complex relationship. This chapter conveys the outstanding issues of cloudy-sky aerosol retrievals of important climate properties and outlines their fruitful connections to other research areas such as in situ measurements and model simulations. The chapter focuses mostly on treating the inverse problems in the context of the passive satellite remote sensing and how they can improve our understanding of the cloud-aerosol interactions. The presentation includes a basis in the inverse problem theory, reviews available approaches and discusses their applications to partly cloudy situations. Potential synergy of observations and model simulations is described as well.

Kassianov, Evgueni I.; Ovchinnikov, Mikhail; Berg, Larry K.; Flynn, Connor J.

2011-06-01T23:59:59.000Z

219

Deposition of Biological Aerosols on HVAC Heat Exchangers  

E-Print Network (OSTI)

LBNL-47669 Deposition of Biological Aerosols on HVAC Heat Exchangers Jeffrey Siegel and Iain Walker of Biological Aerosols on HVAC Heat Exchangers Jeffrey A. Siegel Iain S. Walker, Ph.D. ASHRAE Student Member that are found in commercial and residential HVAC systems of 1 - 6 m/s (200 - 1200 ft/min), particle diameters

220

MATRIX (Multiconfiguration Aerosol TRacker of mIXing state): an aerosol microphysical module for global atmospheric models  

SciTech Connect

A new aerosol microphysical module MATRIX, the Multiconfiguration Aerosol TRacker of mIXing state, and its application in the Goddard Institute for Space Studies (GISS) climate model (ModelE) are described. This module, which is based on the quadrature method of moments (QMOM), represents nucleation, condensation, coagulation, internal and external mixing, and cloud-drop activation and provides aerosol particle mass and number concentration and particle size information for up to 16 mixed-mode aerosol populations. Internal and external mixing among aerosol components sulfate, nitrate, ammonium, carbonaceous aerosols, dust and sea-salt particles are represented. The solubility of each aerosol population, which is explicitly calculated based on its soluble and insoluble components, enables calculation of the dependence of cloud drop activation on the microphysical characterization of multiple soluble aerosol populations. A detailed model description and results of box-model simulations of various aerosol population configurations are presented. The box model experiments demonstrate the dependence of cloud activating aerosol number concentration on the aerosol population configuration; comparisons to sectional models are quite favorable. MATRIX is incorporated into the GISS climate model and simulations are carried out primarily to assess its performance/efficiency for global-scale atmospheric model application. Simulation results were compared with aircraft and station measurements of aerosol mass and number concentration and particle size to assess the ability of the new method to yield data suitable for such comparison. The model accurately captures the observed size distributions in the Aitken and accumulation modes up to particle diameter 1 {micro}m, in which sulfate, nitrate, black and organic carbon are predominantly located; however the model underestimates coarse-mode number concentration and size, especially in the marine environment. This is more likely due to oversimplifications of the representation of sea salt emissions - sea salt emissions are only calculated for two size classes - than to inherent limitations of MATRIX.

Bauer,S.E.; Wright, D.L.; Koch, D.; Lewis, E.R.; McGraw, R.; Chang, L.-S.; Schwartz, S.E.; Ruedy, R.

2008-10-21T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol observing systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

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

SciTech Connect

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.

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

2011-02-01T23:59:59.000Z

222

Monitoring of Observation and Analysis Quality by a Data Assimilation System  

Science Conference Proceedings (OSTI)

The purpose of this paper is to demonstrate the ability of a modern data assimilation system to provide long-term diagnostic facilities to monitor the performance of the observational network. Operational data assimilation systems use short-range ...

A. Hollingsworth; D. B. Shaw; P. Lnnberg; L. Illari; K. Arpe; A. J. Simmons

1986-05-01T23:59:59.000Z

223

On The Importance of Organic Oxygen for Understanding Organic Aerosol  

NLE Websites -- All DOE Office Websites (Extended Search)

On The Importance of Organic Oxygen for Understanding Organic Aerosol On The Importance of Organic Oxygen for Understanding Organic Aerosol Particles Title On The Importance of Organic Oxygen for Understanding Organic Aerosol Particles Publication Type Journal Article Year of Publication 2006 Authors Pang, Yanbo, B. J. Turpin, and Lara A. Gundel Journal Journal of Aerosol Science and Technology Volume 40 Start Page Chapter Pagination 128-133 Abstract This study shows how aerosol organic oxygen data could provide new and independent information about organic aerosol mass, aqueous solubility of organic aerosols, formation of secondary organic aerosol (SOA) and the relative contributions of anthropogenic and biogenic sources. For more than two decades atmospheric aerosol organic mass concentration has usually been estimated by multiplying the measured carbon content by an assumed organic mass (OM)-to-organic carbon (OC ) factor of 1.4. However, this factor can vary from 1.0 to 2.5 depending on location. This great uncertainty about aerosol organic mass limits our understanding of the influence of organic aerosol on climate, visibility and health.New examination of organic aerosol speciation data shows that the oxygen content is the key factor responsible for the observed range in the OM-to-OC factor. When organic oxygen content is excluded, the ratio of non-oxygen organic mass to carbon mass varies very little across different environments (1.12 to 1.14). The non-oxygen-OM-to-non-oxygen OC factor for all studied sites (urban and non-urban) is 1.13± 0.02. The uncertainty becomes an order of magnitude smaller than the uncertainty in the best current estimates of organic mass to organic carbon ratios (1.6± 0.2 for urban and 2.1± 0.2 for non-urban areas). When aerosol organic oxygen data become available, organic aerosol mass can be quite accurately estimated using just OC and organic oxygen (OO) without the need to know whether the aerosol is fresh or aged. In addition, aerosol organic oxygen data will aid prediction of water solubility since compounds with OO-to-OC higher than 0.4 have water solubilities higher than 1g per 100 g water

224

Contribution of Changes in Sea Surface Temperature and Aerosol Loading to the Decreasing Precipitation Trend in Southern China  

Science Conference Proceedings (OSTI)

The effects of increasing sea surface temperature (SST) and aerosol loading in a drought region in Southern China are studied using aerosol optical depth (AOD), low-level cloud cover (LCC), visibility, and precipitation from observed surface data;...

Yanjie Cheng; Ulrike Lohmann; Junhua Zhang; Yunfeng Luo; Zuoting Liu; Glen Lesins

2005-05-01T23:59:59.000Z

225

An Ultralight Aircraft as Platform for Research in the Lower Troposphere: System Performance and First Results from Radiation Transfer Studies in Stratiform Aerosol Layers and Broken Cloud Conditions  

Science Conference Proceedings (OSTI)

The ultraviolet actinic radiation flux governing the photochemical reactions in the atmosphere is dependent on the optical properties of atmospheric aerosols and reflective surfaces of ground and clouds. Theoretical models exist for horizontal ...

Wolfgang Junkermann

2001-06-01T23:59:59.000Z

226

Development and Characterization of a Thermodenuder for Aerosol Volatility Measurements  

SciTech Connect

This SBIR Phase I project addressed the critical need for improved characterization of carbonaceous aerosol species in the atmosphere. The proposed work focused on the development of a thermodenuder (TD) system capable of systematically measuring volatility profiles of primary and secondary organic aerosol species and providing insight into the effects of absorbing and nonabsorbing organic coatings on particle absorption properties. This work provided the fundamental framework for the generation of essential information needed for improved predictions of ambient aerosol loadings and radiative properties by atmospheric chemistry models. As part of this work, Aerodyne Research, Inc. (ARI) continued to develop and test, with the final objective of commercialization, an improved thermodenuder system that can be used in series with any aerosol instrument or suite of instruments (e.g., aerosol mass spectrometers-AMS, scanning mobility particle sizers-SMPS, photoacoustic absorption spectrometers-PAS, etc.) to obtain aerosol chemical, physical, and optical properties as a function of particle volatility. In particular, we provided the proof of concept for the direct coupling of our improved TD design with a full microphysical model to obtain volatility profiles for different organic aerosol components and to allow for meaningful comparisons between different TD-derived aerosol measurements. In a TD, particles are passed through a heated zone and a denuding (activated charcoal) zone to remove semi-volatile material. Changes in particle size, number concentration, optical absorption, and chemical composition are subsequently detected with aerosol instrumentation. The aerosol volatility profiles provided by the TD will strengthen organic aerosol emission inventories, provide further insight into secondary aerosol formation mechanisms, and provide an important measure of particle absorption (including brown carbon contributions and identification, and absorption enhancements due to coatings on soot particles). The successfully completed Phase I project included construction of a prototype design for the TD with detailed physical modeling, testing with laboratory and ambient aerosol particles, and the initiation of a detailed microphysical model of the aerosol particles passing through the TD to extract vapor pressure distributions. The objective of the microphysical model is to derive vapor pressure distributions (i.e. vapor pressure ranges, including single chemical compounds, mixtures of known compounds, and complex real-world aerosols, such as SOA, and soot particles with absorbing and nonabsorbing coatings) from TD measurements of changes in particle size, mass, and chemical composition for known TD temperatures and flow rates (i.e. residence times). The proposed Phase II project was designed to optimize several TD systems for different instrument applications and to combine the hardware and modeling into a robust package for commercial sales.

Dr. Timothy Onasch

2009-09-09T23:59:59.000Z

227

ARM - Measurement - Aerosol particle size  

NLE Websites -- All DOE Office Websites (Extended Search)

particle size particle size 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 : Aerosol particle size Linear size (e.g. radius or diameter) of an aerosol particle. Categories Aerosols Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. Field Campaign Instruments AEROSMASSSPEC : Aerosol Mass Spectrometer CPI : Cloud Particle Imager DRI-GND : Desert Research Institute Ground-Based Aerosol Instruments DRUM-AEROSOL : Drum Aerosol Sampler AEROSOL-TOWER-EML : EML Tower based Aerosol Measurements

228

Monodisperse aerosol generator  

DOE Patents (OSTI)

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.

Ortiz, L.W.; Soderholm, S.C.

1988-09-19T23:59:59.000Z

229

RACORO aerosol data processing  

Science Conference Proceedings (OSTI)

The RACORO aerosol data (cloud condensation nuclei (CCN), condensation nuclei (CN) and aerosol size distributions) need further processing to be useful for model evaluation (e.g., GCM droplet nucleation parameterizations) and other investigations. These tasks include: (1) Identification and flagging of 'splash' contaminated Twin Otter aerosol data. (2) Calculation of actual supersaturation (SS) values in the two CCN columns flown on the Twin Otter. (3) Interpolation of CCN spectra from SGP and Twin Otter to 0.2% SS. (4) Process data for spatial variability studies. (5) Provide calculated light scattering from measured aerosol size distributions. Below we first briefly describe the measurements and then describe the results of several data processing tasks that which have been completed, paving the way for the scientific analyses for which the campaign was designed. The end result of this research will be several aerosol data sets which can be used to achieve some of the goals of the RACORO mission including the enhanced understanding of cloud-aerosol interactions and improved cloud simulations in climate models.

Elisabeth Andrews

2011-10-31T23:59:59.000Z

230

A Comparison of Variational and Ensemble-Based Data Assimilation Systems for Reanalysis of Sparse Observations  

Science Conference Proceedings (OSTI)

An observing system experiment, simulating a surface-only observing network representative of the 1930s, is carried out with three- and four-dimensional variational data assimilation systems (3D-VAR and 4D-VAR) and an ensemble-based data ...

Jeffrey S. Whitaker; Gilbert P. Compo; Jean-Nol Thpaut

2009-06-01T23:59:59.000Z

231

An observability formulation for nonlinear power systems modeled as differential algebraic systems.  

E-Print Network (OSTI)

??Recently the power system industry has witnessed an increase in system automation affecting all aspects of operation and requiring knowledge of system states that are (more)

Dafis, Chris J.

2005-01-01T23:59:59.000Z

232

Evolution of Organic Aerosols in the Atmosphere.  

SciTech Connect

Organic aerosol (OA) particles affect climate forcing and human health, but their sources and evolution remain poorly characterized. We present a unifying model framework that describes the atmospheric evolution of OA and is constrained and motivated by new, high time resolution, experimental characterizations of their composition, volatility, and oxidation state. OA and OA-precursor gases evolve by becoming increasingly oxidized, less volatile, and more hygroscopic, leading to the formation of large amounts of oxygenated organic aerosol (OOA) mass that has comparable concentrations to sulfate aerosol over the Northern Hemisphere. Our new model framework captures the dynamic aging behavior observed in the atmosphere and the laboratory and can serve as a basis for improving parameterizations in regional and global models.

Jimenez, J. L.; Canagaratna, M. R.; Donahue, N. M.; Prevot, A. S. H.; Zhang, Qi; Kroll, Jesse H.; DeCarlo, Peter F.; Allan, James D.; Coe, H.; Ng, N. L.; Aiken, Allison; Docherty, Kenneth S.; Ulbrich, Ingrid M.; Grieshop, A. P.; Robinson, A. L.; Duplissy, J.; Smith, J. D.; Wilson, K. R.; Lanz, V. A.; Hueglin, C.; Sun, Y. L.; Tian, J.; Laaksonen, A.; Raatikainen, T.; Rautiainen, J.; Vaattovaara, P.; Ehn, M.; Kulmala, M.; Tomlinson, Jason M.; Collins, Donald R.; Cubison, Michael J.; Dunlea, E. J.; Huffman, John A.; Onasch, Timothy B.; Alfarra, M. R.; Williams, Paul I.; Bower, K.; Kondo, Yutaka; Schneider, J.; Drewnick, F.; Borrmann, S.; Weimer, S.; Demerjian, K.; Salcedo, D.; Cottrell, L.; Griffin, Robert; Takami, A.; Miyoshi, T.; Hatakeyama, S.; Shimono, A.; Sun, J. Y.; Zhang, Y. M.; Dzepina, K.; Kimmel, Joel; Sueper, D.; Jayne, J. T.; Herndon, Scott C.; Trimborn, Achim; Williams, L. R.; Wood, Ezra C.; Middlebrook, A. M.; Kolb, C. E.; Baltensperger, Urs; Worsnop, Douglas R.

2009-12-11T23:59:59.000Z

233

Spectral Signatures of Polar Stratospheric Clouds and Sulfate Aerosol  

Science Conference Proceedings (OSTI)

Multiwavelength observations of Antarctic and midlatitude aerosol by the Cryogenic Limb Array Etalon Spectrometer (CLAES) experiment on the Upper Atmosphere Research Satellite are used to demonstrate a technique that identifies the location of ...

S. T. Massie; P. L. Bailey; J. C. Gille; E. C. Lee; J. L. Mergenthaler; A. E. Roche; J. B. Kumer; E. F. Fishbein; J. W. Waters; W. A. Lahoz

1994-10-01T23:59:59.000Z

234

Long-term Statistics of Continental Cumuli: Does Aerosol Trigger Cumulus Variability?  

Science Conference Proceedings (OSTI)

Atmospheric aerosols may control the formation, maintenance, and dissipation of cumuli by changing their microphysics. Recent observational and modeling results exist both in support and against strong potential impacts of aerosol [1-3]. Typically, the aerosol impact on water clouds has been investigated for regions with high aerosol loading and/or large atmospheric moisture [4]. Can we provide observational evidence of the aerosol-cloud relationship for a relatively dry continental region with low/moderate aerosol burden? To address this question, we revisit the aerosol-cloud relationship at the Atmospheric Radiation Measurement (ARM) Climate Research Facility (ACRF) Southern Great Plains (SGP) site. In comparison with highly polluted regions, the SGP site is characterized by relatively small-to-moderate aerosol loading. Also, moisture content is small-to-moderate (compared to marine and coastal regions) for the SGP site. Because cumulus clouds have important impacts on climate forcing estimations [5] and are susceptible to aerosol effects [6], we focus on fair-weather cumuli (FWC) and their association with aerosol concentration and other potentially important factors. This association is investigated using a new 8-year aerosol and cloud climatology (2000-2007) developed with collocated and coincident surface and satellite observations.

Kassianov, Evgueni I.; Berg, Larry K.; McFarlane, Sally A.; Flynn, Connor J.; Turner, David D.

2009-02-01T23:59:59.000Z

235

Wavelength Dependence of Aerosol Extinction Coefficient for Stratospheric Aerosols  

Science Conference Proceedings (OSTI)

A simple empirical formula for the wavelength dependence of the aerosol extinction coefficient is proposed. The relationship between the constants in the formula and the variable parameter in the aerosol size distribution is explicitly expressed. ...

Glenn K. Yue

1986-11-01T23:59:59.000Z

236

Aerosols in a Changing Atmosphere: From Detailed Aerosol Microphysics...  

NLE Websites -- All DOE Office Websites (Extended Search)

Aerosols in a Changing Atmosphere: From Detailed Aerosol Microphysics to Policy Applications Speaker(s): Susanne Bauer Date: December 6, 2011 - 4:00pm Location: 90-4133 Seminar...

237

Physicochemical Characterization of Capstone Depleted Uranium Aerosols I: Uranium Concentration in Aerosols as a Function of Time and Particle Size  

SciTech Connect

During the Capstone Depleted Uranium (DU) Aerosol Study, aerosols containing depleted uranium were produced inside unventilated armored vehicles (i.e., Abrams tanks and Bradley Fighting Vehicles) by perforation with large-caliber DU penetrators. These aerosols were collected and characterized, and the data were subsequently used to assess human health risks to personnel exposed to DU aerosols. The DU content of each aerosol sample was first quantified by radioanalytical methods, and selected samples, primarily those from the cyclone separator grit chambers, were analyzed radiochemically. Deposition occurred inside the vehicles as particles settled on interior surfaces. Settling rates of uranium from the aerosols were evaluated using filter cassette samples that collected aerosol as total mass over eight sequential time intervals. A moving filter was used to collect aerosol samples over time particularly within the first minute after the shot. The results demonstrate that the peak uranium concentration in the aerosol occurred in the first 10 s, and the concentration decreased in the Abrams tank shots to about 50% within 1 min and to less than 2% 30 min after perforation. In the Bradley vehicle, the initial (and maximum) uranium concentration was lower than those observed in the Abrams tank and decreased more slowly. Uranium mass concentrations in the aerosols as a function of particle size were evaluated using samples collected in the cyclone samplers, which collected aerosol continuously for 2 h post perforation. The percentages of uranium mass in the cyclone separator stages from the Abrams tank tests ranged from 38% to 72% and, in most cases, varied with particle size, typically with less uranium associated with the smaller particle sizes. Results with the Bradley vehicle ranged from 18% to 29% and were not specifically correlated with particle size.

Parkhurst, MaryAnn; Cheng, Yung-Sung; Kenoyer, Judson L.; Traub, Richard J.

2009-03-01T23:59:59.000Z

238

Lidar Observations of Banded Convection during BLX83  

Science Conference Proceedings (OSTI)

Lidar observations of clear-air convection during the 1983 Boundary Layer Experiment (BLX83) reveal the presence of elongated, parallel regions of updrafts marked by enhanced aerosol backscattering. These linear (banded) aerosol structures were ...

R. A. Ferrare; J. L. Schols; E. W. Eloranta; R. Coulter

1991-03-01T23:59:59.000Z

239

A New Hypothesis for the Vertical Distribution of Atmospheric Aerosols  

E-Print Network (OSTI)

A simple model which can explain the observed vertical distribution and size spectrum of atmospheric aerosol has been proposed. The model is based on a new physical hypothesis for the vertical mass exchange between the troposphere and the stratosphere. The vertical mass excange takes place through a gravity wave feedback mechanism. There is a close agreement between the model predicted aerosol distribution and size spectrum and the observed distributions.

A. Mary Selvam; A. S. Ramachandra Murty; Bh. V. Ramanamurty

1999-12-05T23:59:59.000Z

240

Cross-layer virtual observers for embedded multiprocessor system-on-chip (MPSoC)  

Science Conference Proceedings (OSTI)

There is a growing concern about the increasing vulnerability of future computing systems to errors in the underlying hardware due to manufacturing process variability, exponentially increasing power dissipation and heating, as well as drastic and harsh ... Keywords: cross-layer design approach, cyber physical systems, estimators, multi-processor systems-on-chip, observers, reflective middleware

Santanu Sarma; Nikil Dutt; Nalini Venkatasubramanian

2012-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol observing systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Predictability of event occurrences in partially-observed discrete-event systems  

Science Conference Proceedings (OSTI)

This paper studies the problem of predicting occurrences of a significant event in a partially-observed discrete-event system. The predictability of occurrences of an event in a system is defined in the context of formal languages. The predictability ... Keywords: Diagnosis, Discrete-event systems, Prediction

Sahika Genc; Stphane Lafortune

2009-02-01T23:59:59.000Z

242

Morphology effects on polydispersed aerosol deposition rates  

Science Conference Proceedings (OSTI)

In the analysis of severe nuclear accidents, accurate prediction of aerosol deposition is important since, among other things, this influences the distribution of radioactive decay heat within the primary system and containment compartments. The fact that the aerosol cloud is not comprised of dense isolated spherical particles of only one size inevitably complicates such calculations but must be taken into account. Some particle deposition mechanisms are more sensitive to particle size and morphology than others so that simplifying assumptions valid for one mechanism [such as particle thermophoresis (notoriously size and morphology insensitive)] may be seriously in error for others (e.g., convective Brownian diffusion or eddy impaction). This paper deals with aggregate aerosol deposition.

Rosner, D.E.; Tandon, P. [Yale Univ., New Haven, CT (United States); Khalil, Y.F. [Northeast Utilities Service Co., Berlin, CT (United States)

1997-12-01T23:59:59.000Z

243

Evaluation of mixing in three duct configurations and development of a Generic Tee Plenum System (GTPS) for application to single point aerosol sampling  

E-Print Network (OSTI)

A Generic Tee Plenum System (GTPS) based on three different duct systems (Configuration-I, II and III) used in nuclear facilities has been developed which creates suitable conditions for single point representative sampling. This single point sampling is an acceptable standard methodology for sampling emissions from stacks and ducts of the nuclear industry (ANSI/HPS N13.1-1999 and US EPA 2000). These air duct systems in nuclear facilities must meet the requirements of ANSI/HPS N13.1-1999 that the exhaust airflow be monitored with continuous sampling in case of an accidental release of airborne radionuclides. Results show that the GTPS system performance is well within the requirements of ANSI/HPS N13.1-1999 - the COVs for velocity, tracer gas concentration and 10 [u]m AD aerosol particle are less than the mixing criteria 20% of ANSI/HPS N13.1-1999. The objective of this work is to provide data on the mixing effectiveness of various duct configurations found in nuclear facilities. These data can be applied in new facilities as well as in upgrades to existing U.S. DOE nuclear facilities. The data should also provide a basis for testing the efficacy of mixing models that may be generated in the future. Experiments were conducted to characterize the degree of mixing at downstream locations as affected by several types of flow disturbances, including a plenum consisting with duct intakes, a rectangular elbow with turning vanes, 90? elbows, tees, commercial static mixing device and GTPS in circular and non-circular ducts. The mixing performance of a plenum duct configuration (Configuration-I) with two-intake sources was studied to develop recommendations for suitable sampling locations less than 4 duct diameters downstream of a plenum. Several mixing element options were considered both upstream and downstream of a security grille. A stack model system with straight circular ducts downstream of rectangular elbow with turning vanes (Configuration-II) were characterized for velocity, tracer gas and particle concentration profiles COVs. The application of a mixing system was designed for achieving maximum conditions in round-elbow and tee element system interfaced to a stack (Configuration-III). Several options were considered when using different types of elbows upstream of the stack. Numerical studies for velocity profile in the GTPS were conducted with a commercial computational fluid dynamics (CFD) software, FLUENT. Good agreement was found between the experimental and numerical results.

Han, Tae Won

2003-01-01T23:59:59.000Z

244

AerosolCCN Closure at a Semi-rural Site  

Science Conference Proceedings (OSTI)

aerosol size distributions and size-resolved aerosol compositions measured by ... Keywords Cloud condensation nuclei, closure study, organic aerosols, Khler.

245

Formation mechanisms and quantification of organic nitrates in atmospheric aerosol  

E-Print Network (OSTI)

Atmospheric submicron aerosol . . . . . . . 2.3 Partitioningon SOA organic aerosol formation alkyl nitrate and secondaryPeroxy radical fate . . . . . . Aerosol . . . . . . . .

Rollins, Andrew Waite

2010-01-01T23:59:59.000Z

246

The Doppler Aerosol Wind Lidar (DAWN) Airborne, Wind-Profiling, Coherent-Detection Lidar System: Overview and Preliminary Flight Results  

Science Conference Proceedings (OSTI)

The first airborne wind measurements of a pulsed, 2-micron solid-state, high-energy, wind-profiling lidar system for airborne measurements are presented. The laser pulse energy is the highest to date in an eyesafe airborne wind lidar system. This ...

Michael J. Kavaya; Jeffrey Y. Beyon; Grady J. Koch; Mulugeta Petros; Paul J. Petzar; Upendra N. Singh; Bo C. Trieu; Jirong Yu

247

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

E-Print Network (OSTI)

and R. Ruedy, Matrix (multiconfiguration aerosol tracker ofmixing state): An aerosol microphysical module for globalAn investigative review, Aerosol Sci. Technol. , Vol. 40,

Bauer, Susanne E.

2010-01-01T23:59:59.000Z

248

ARM - Field Campaign - Shortwave Radiation and Aerosol Intensive  

NLE Websites -- All DOE Office Websites (Extended Search)

govCampaignsShortwave Radiation and Aerosol Intensive Observation govCampaignsShortwave Radiation and Aerosol Intensive Observation Periods Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Shortwave Radiation and Aerosol Intensive Observation Periods 1998.08.03 - 1998.08.28 Lead Scientist : Warren Wiscombe For data sets, see below. Summary Wednesday, August 5, 1998: IOP Opening Activities: The IOP updates for the Shortwave/Aerosol/BDRF will be composed from notes taken during briefing sessions lead by Don Cahoon and company each night at the Marland Mansion in Ponca City. IOP Status as of 8/4/98 Weather forecasts indicate that cloudy conditions will prevail for the next few days. The Helicopter is on standby for clear sky conditions. Model output indicates clear sky's may move in later this week.

249

The Accuracy of Trajectory Models as Revealed by the Observing System Simulation Experiments  

Science Conference Proceedings (OSTI)

Fourteen observing system simulation experiments (OSSE) wore conducted using the results from a mesoscale model on the Oxidation and Scavenging Characteristics of April Rains(OSCAR) experiment to test the accuracy of trajectory models. Our ...

Ying-Hwa Kuo; Marina Skumanich; Philip L. Haagenson; Julius S. Chang

1985-11-01T23:59:59.000Z

250

Total Lightning Characteristics Relative to Radar and Satellite Observations of Oklahoma Mesoscale Convective Systems  

Science Conference Proceedings (OSTI)

The advent of regional very high frequency (VHF) Lightning Mapping Arrays (LMAs) makes it possible to begin analyzing trends in total lightning characteristics in ensembles of mesoscale convective systems (MCSs). Flash initiations observed by the ...

Jeffrey A. Makowski; Donald R. MacGorman; Michael I. Biggerstaff; William H. Beasley

2013-05-01T23:59:59.000Z

251

Composite Life Cycle of Maritime Tropical Mesoscale Convective Systems in Scatterometer and Microwave Satellite Observations  

Science Conference Proceedings (OSTI)

This study examines scatterometer-observed surface wind divergence and vorticity, along with precipitable water (PW), across the life cycle of tropical maritime mesoscale convective systems (MCSs) as resolved in 0.5 data. Simple composites were ...

Brian Mapes; Ralph Milliff; Jan Morzel

2009-01-01T23:59:59.000Z

252

A Lightweight Observation System for Atmospheric Carbon Dioxide Concentration Using a Small Unmanned Aerial Vehicle  

Science Conference Proceedings (OSTI)

To make the investigation of the temporal and spatial variations of atmospheric CO2 in and above the planetary boundary layer more flexible and economical, a lightweight observation system using a small unmanned aerial vehicle has been developed ...

T. Watai; T. Machida; N. Ishizaki; G. Inoue

2006-05-01T23:59:59.000Z

253

Finescale Vertical Structure of the Upwelling System off Southern Peru as Observed from Glider Data  

Science Conference Proceedings (OSTI)

The upwelling system off southern Peru has been observed using an autonomous underwater vehicle (a Slocum glider) during OctoberNovember 2008. Nine cross-front sections have been carried out across an intense upwelling cell near 14S. During ...

Alice Pietri; Pierre Testor; Vincent Echevin; Alexis Chaigneau; Laurent Mortier; Gerard Eldin; Carmen Grados

2013-03-01T23:59:59.000Z

254

Using Precipitation Observations in a Mesoscale Short-Range Ensemble Analysis and Forecasting System  

Science Conference Proceedings (OSTI)

A simple method to assimilate precipitation data from a synthesis of radar and gauge data is developed to operate alongside an ensemble Kalman filter that assimilates hourly surface observations. The mesoscale ensemble forecast system consists of ...

Tadashi Fujita; David J. Stensrud; David C. Dowell

2008-06-01T23:59:59.000Z

255

Numerical Experiments on Consistent Horizontal and Vertical Resolution for Atmospheric Models and Observing Systems  

Science Conference Proceedings (OSTI)

Simple numerical experiments are performed in order to determine the effects of inconsistent combinations of horizontal and vertical resolution in both atmospheric models and observing systems. In both cases, we find that inconsistent spatial ...

Michael S. Fox-Rabinovitz; Richard S. Lindzen

1993-01-01T23:59:59.000Z

256

A generic multi-scale modeling framework for reactive observing systems: an overview  

Science Conference Proceedings (OSTI)

Observing systems facilitate scientific studies by instrumenting the real world and collecting corresponding measurements, with the aim of detecting and tracking phenomena of interest. A wide range of critical environmental monitoring objectives in resource ...

Leana Golubchik; David Caron; Abhimanyu Das; Amit Dhariwal; Ramesh Govindan; David Kempe; Carl Oberg; Abhishek Sharma; Beth Stauffer; Gaurav Sukhatme; Bin Zhang

2006-05-01T23:59:59.000Z

257

Filtering Partially Observed Multiscale Systems with Heterogeneous Multiscale MethodsBased Reduced Climate Models  

Science Conference Proceedings (OSTI)

This paper presents a fast reduced filtering strategy for assimilating multiscale systems in the presence of observations of only the macroscopic (or large scale) variables. This reduced filtering strategy introduces model errors in estimating the ...

Emily L. Kang; John Harlim

2012-03-01T23:59:59.000Z

258

An Observing System Simulation Experiment for an Optimal Moored Instrument Array in the Tropical Indian Ocean  

Science Conference Proceedings (OSTI)

In this paper, a series of observing system simulation experiments (OSSEs) are used to study the design of a proposed array of instrumented moorings in the Indian Ocean (IO) outlined by the IO panel of the Climate Variability and Predictability (...

Joaquim Ballabrera-Poy; Eric Hackert; Raghu Murtugudde; Antonio J. Busalacchi

2007-07-01T23:59:59.000Z

259

Bidirectional Reflectance Round-Robin in Support of the Earth Observing System Program  

Science Conference Proceedings (OSTI)

Laboratory measurements of the bidirectional reflectance distribution function (BRDF) of diffuse reflectors are required to support calibration in the Earth Observing System (EOS) program of the National Aeronautics and Space Administration. To ...

E. A. Early; P. Y. Barnes; B. C. Johnson; J. J. Butler; C. J. Bruegge; S. F. Biggar; P. R. Spyak; M. M. Pavlov

2000-08-01T23:59:59.000Z

260

The United States Cooperative Climate-Observing Systems: Reflections and Recommendations  

Science Conference Proceedings (OSTI)

The system for the collection and archiving of climatic data from approximately 7000 cooperative observing stations across the United States is in need of improvement. Despite the efforts of many dedicated volunteers and professionals, suspect or ...

David A. Robinson

1990-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol observing systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

A System for the Hourly Assimilation of Surface Observations in Mountainous and Flat Terrain  

Science Conference Proceedings (OSTI)

An assimilation system is presented that was designed to provide timely, detailed, and coherent analyses of surface data, even when the data are collected in rough terrain where station elevations differ widely and observations are often subject ...

Patricia A. Miller; Stanley G. Benjamin

1992-10-01T23:59:59.000Z

262

An Observing System Simulation Experiment for the Laser Atmospheric Wind Sounder (LAWS)  

Science Conference Proceedings (OSTI)

A series of observing system simulation experiments (OSSES) was conducted to assess the potential impact of the Laser Atmospheric Wind Sounder (LAWS) instrument on a 5-day forecast using the Florida State University (FSU) primitive equation ...

G. D. Rohaly; T. N. Krishnamurti

1993-09-01T23:59:59.000Z

263

Saharan Dust Aerosol Radiative Forcing Measured from Space  

Science Conference Proceedings (OSTI)

This study uses data collected from the Clouds and the Earth's Radiant Energy System (CERES) and the Moderate Resolution Imaging Spectroradiometer (MODIS) instruments to determine Saharan dust broadband shortwave aerosol radiative forcing over ...

F. Li; A. M. Vogelmann; V. Ramanathan

2004-07-01T23:59:59.000Z

264

An Integrated Global Observing System For Sea Surface Temperature Using Satellites and in Situ Data: Research to Operations  

Science Conference Proceedings (OSTI)

This paper describes the optimal design and its research-to-operation transition of an integrated global observing system of satellites and in situ observations. The integrated observing system is used for climate assessment using sea surface ...

H-M. Zhang; R. W. Reynolds; R. Lumpkin; R. Molinari; K. Arzayus; M. Johnson; T. M. Smith

2009-01-01T23:59:59.000Z

265

Highly stable aerosol generator  

DOE Patents (OSTI)

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.

DeFord, Henry S. (Kennewick, WA); Clark, Mark L. (Kennewick, WA)

1981-01-01T23:59:59.000Z

266

Highly stable aerosol generator  

DOE Patents (OSTI)

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.

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

1981-11-03T23:59:59.000Z

267

Direct and semidirect aerosol effects of Southern African biomass burning aerosol  

Science Conference Proceedings (OSTI)

The direct and semi-direct radiative effects of biomass burning aerosols from Southern African fires during July-October are investigated using 20 year runs of the Community Atmospheric Model (CAM) coupled to a slab ocean model. The aerosol optical depth is constrained using observations in clear skies from MODIS and for aerosol layers above clouds from CALIPSO. Over the ocean, where the absorbing biomass burning aerosol layers are primarily located above cloud, negative top of atmosphere (TOA) semi-direct radiative effects associated with increased low cloud cover dominate over a weaker positive all-sky direct radiative effect (DRE). In contrast, over the land where the aerosols are often below or within cloud layers, reductions in cloud liquid water path (LWP) lead to a positive semi-direct radiative effect that dominates over a near-zero DRE. Over the ocean, the cloud response can be understood as a response to increased lower tropospheric stability (LTS) which is caused both by aerosol absorptive warming in overlying layers and surface cooling in response to direct aerosol forcing. The ocean cloud changes are robust to changes in the cloud parameterization (removal of the hard-wired dependence of clouds on LTS), suggesting that they are physically realistic. Over land where cloud cover changes are minimal, decreased LWP is consistent with weaker convection driven by increased static stability. Over the entire region the overall TOA radiative effect from the biomass burning aerosols is almost zero due to opposing effects over the land and ocean. However, the surface forcing is strongly negative requiring a reduction in precipitation. This is primarily realized through reductions in convective precipitation on both the southern and northern flanks of the convective precipitation region spanning the equatorial rainforest and the ITCZ in the southern Sahel. The changes are consistent with the low-level aerosol forced cooling pattern. The results highlight the importance of semi-direct radiative effects and precipitation responses for determining the climatic effects of aerosols in the African region.

Sakaeda, Naoko; Wood, Robert; Rasch, Philip J.

2011-06-21T23:59:59.000Z

268

Clouds and the Earth's Radiant Energy System (CERES): An Earth Observing System Experiment  

Science Conference Proceedings (OSTI)

Clouds and the Earth's Radiant Energy System (CERES) is an investigation to examine the role of cloud/radiation feedback in the Earth's climate system. The CERES broadband scanning radiometers are an improved version of the Earth Radiation Budget ...

Bruce A. Wielicki; Bruce R. Barkstrom; Edwin F. Harrison; Robert B. Lee III; G. Louis Smith; John E. Cooper

1996-05-01T23:59:59.000Z

269

Atmospheric Aerosol Limb Scanning Based on the Lunar Eclipses Photometry  

E-Print Network (OSTI)

The work is devoted to the analysis of the surface photometric observations of two total lunar eclipses in 2004. The lunar surface relative brightness distribution inside the umbra was used to retrieve the vertical distribution of aerosol extinction of the solar radiation expanding by a tangent path and its dependence on the location at the limb of the Earth. The upper altitude of troposphere aerosol layer was estimated for different latitude zones. The correlation between additional aerosol extinction in the upper troposphere and cyclones was investigated.

O. S. Ugolnikov; I. A. Maslov

2005-10-06T23:59:59.000Z

270

BNL | Aerosol, Cloud, Precipitation Interactions  

NLE Websites -- All DOE Office Websites (Extended Search)

Cloud-Aerosol-Precipitation Interactions Cloud-Aerosol-Precipitation Interactions Atmospheric aerosols exert important "indirect effects" on clouds and climate by serving as cloud condensation nuclei (CCN) and ice nuclei that affect cloud radiative and microphysical properties. For example, an increase in CCN increases the number concentration of droplets enhances cloud albedo, and suppresses precipitation that alters cloud coverage and lifetime. However, in the case of moist and strong convective clouds, increasing aerosols may increase precipitation and enhance storm development. Although aerosol-induced indirect effects on climate are believed to have a significant impact on global climate change, estimating their impact continues to be one of the most uncertain climate forcings.

271

Jankovic Aerosol Characterization.ppt  

NLE Websites -- All DOE Office Websites (Extended Search)

Characterization, Characterization, Aerosol Characterization, Interpretation, and Interpretation, and Application of Data Application of Data NSRC Symposium NSRC Symposium July 8, 2008 John Jankovic, CIH CIH Center for Nanophase Materials Sciences Center for Nanophase Materials Sciences Aerosol Characterization, Interpretation, and Aerosol Characterization, Interpretation, and Application of Data Application of Data Department of Energy (DOE) Nanoscale Science Research Centers (NSRC) developing Approach to Nanomaterial ES&H - The CNMS Approach * Establish Exposure Control Guideline (ECG) - Characterize Aerosol * Collect and interpret data * Assign Process to a Control Band Aerosol Particle Characterization * Size distribution (geometric mean and geometric standard deviation related to either mass, surface, or number)

272

Geometrical Optics of Dense Aerosols  

SciTech Connect

Assembling a free-standing, sharp-edged slab of homogeneous material that is much denser than gas, but much more rare ed than a solid, is an outstanding technological challenge. The solution may lie in focusing a dense aerosol to assume this geometry. However, whereas the geometrical optics of dilute aerosols is a well-developed fi eld, the dense aerosol limit is mostly unexplored. Yet controlling the geometrical optics of dense aerosols is necessary in preparing such a material slab. Focusing dense aerosols is shown here to be possible, but the nite particle density reduces the eff ective Stokes number of the flow, a critical result for controlled focusing. __________________________________________________

Hay, Michael J.; Valeo, Ernest J.; Fisch, Nathaniel J.

2013-04-24T23:59:59.000Z

273

Observing System Simulation Experiments (OSSEs) for the Mid-Columbia Basin  

DOE Green Energy (OSTI)

The overall goal of this multi-phased research project known as WindSENSE is to develop an observation system deployment strategy that would improve wind power generation forecasts. The objective of the deployment strategy is to produce the maximum benefit for 1- to 6-hour ahead forecasts of wind speed at hub-height ({approx}80 m). In this phase of the project the focus is on the Mid-Columbia Basin region, which encompasses the Bonneville Power Administration (BPA) wind generation area (Figure 1) that includes the Klondike, Stateline, and Hopkins Ridge wind plants. There are two tasks in the current project effort designed to validate the Ensemble Sensitivity Analysis (ESA) observational system deployment approach in order to move closer to the overall goal: (1) Perform an Observing System Experiment (OSE) using a data denial approach. The results of this task are presented in a separate report. (2) Conduct a set of Observing System Simulation Experiments (OSSE) for the Mid-Colombia basin region. This report presents the results of the OSSE task. The specific objective is to test strategies for future deployment of observing systems in order to suggest the best and most efficient ways to improve wind forecasting at BPA wind farm locations. OSSEs have been used for many years in meteorology to evaluate the potential impact of proposed observing systems, determine tradeoffs in instrument design, and study the most effective data assimilation methodologies to incorporate the new observations into numerical weather prediction (NWP) models (Atlas 1997; Lord 1997). For this project, a series of OSSEs will allow consideration of the impact of new observing systems of various types and in various locations.

Zack, J; Natenberg, E J; Knowe, G V; Waight, K; Manobianco, J; Hanley, D; Kamath, C

2011-09-13T23:59:59.000Z

274

Studies of urban aerosols in the Pearl River Delta Region using lidar.  

E-Print Network (OSTI)

??In the Pearl River Delta (PRD) Region of China, three Lidar systems have been employed for monitoring aerosol distribution: a mobile micro-pulse Lidar of City (more)

Chan, Lai Man Raymond (???)

2007-01-01T23:59:59.000Z

275

OBSERVE: Occupancy-Based System for Efficient Reduction of HVAC Energy  

E-Print Network (OSTI)

control conditioning strategies. Using strategies based on sensor network occupancy model predictions, weOBSERVE: Occupancy-Based System for Efficient Reduction of HVAC Energy Varick L. Erickson, Miguel Á Descriptors I.6.5 [Simulation and Modeling]: Model Development; J.7 [Computers In Other Systems]: Command

Cerpa, Alberto E.

276

A New Assessment of the Aerosol First Indirect Effect  

NLE Websites -- All DOE Office Websites (Extended Search)

New Assessment of the Aerosol First Indirect Effect New Assessment of the Aerosol First Indirect Effect Shao, Hongfei Florida State University Liu, Guosheng Florida State University Category: Aerosols The aerosol first indirect effect is known to cool the Earth radiatively. However, its magnitude is very uncertain; large discrepancies exist among the observed values published in the literature. In this study, we first survey the published values of those parameters used for describing the first indirect effect. By analyzing the discrepancies among these values, we show that the first indirect effect has been overestimated by many investigators due to an improper parameter being used. Therefore, we introduce a more meaningful parameter to measure this effect. We estimated the first indirect effect using the new parameter based on observational

277

A Numerical Sensitivity Study of Aerosol Influence on Immersion Freezing  

NLE Websites -- All DOE Office Websites (Extended Search)

Numerical Sensitivity Study of Aerosol Influence on Immersion Freezing Numerical Sensitivity Study of Aerosol Influence on Immersion Freezing in Mixed-Phase Stratiform Clouds Gijs de Boer, Tempei Hashino, Edwin W. Eloranta and Gregory J. Tripoli The University of Wisconsin - Madison (1) Introduction (1) Introduction Mixed-phase stratiform clouds are commonly observed at high latitudes (Shupe et al., 2006; de Boer et al., 2009a). These clouds significaly impact the atmospheric radiative

278

Surface shortwave aerosol radiative forcing during the Atmospheric Radiation Measurement Mobile Facility deployment in Niamey, Niger  

SciTech Connect

This study presents ground-based remote sensing measurements of aerosol optical properties and corresponding shortwave surface radiative effect calculations for the deployment of the Atmospheric Radiation Measurement (ARM) Programs Mobile Facility (AMF) to Niamey, Niger during 2006. Aerosol optical properties including aerosol optical depth (AOD), single scattering albedo (SSA), and asymmetry parameter (AP) were derived from multi-filter rotating shadowband radiometer (MFRSR) measurements during the two dry seasons (Jan-Apr and Oct-Dec) at Niamey. The vertical distribution of aerosol extinction was derived from the collocated micropulse lidar (MPL). The aerosol optical properties and vertical distribution of extinction varied significantly throughout the year, with higher AOD, lower SSA, and deeper aerosol layers during the Jan-Apr time period, when biomass burning aerosol layers were more frequent. Using the retrieved aerosol properties and vertical extinction profiles, broadband shortwave surface fluxes and atmospheric heating rate profiles were calculated. Corresponding calculations with no aerosol were used to estimate the aerosol direct radiative effect at the surface. Comparison of the calculated surface fluxes to observed fluxes for non-cloudy periods indicated that the remote sensing retrievals provided a reasonable estimation of the optical properties, with mean differences between calculated and observed fluxes of less than 5 W/m2 and RMS differences less than 25 W/m2. Sensitivity tests for a particular case study showed that the observed fluxes could be matched with variations of < 10% in the inputs to the radiative transfer model. We estimated the daily-averaged aerosol radiative effect at the surface by subtracting the clear calculations from the aerosol calculations. The average daily SW aerosol radiative effect over the study period was -27 W/m2, which is comparable to values estimated from satellite data and from climate models with sophisticated dust parameterizations.

McFarlane, Sally A.; Kassianov, Evgueni I.; Barnard, James C.; Flynn, Connor J.; Ackerman, Thomas P.

2009-03-18T23:59:59.000Z

279

Chemical Bonding and Structural Information of Black Carbon Reference Materials and Individual Carbonaceous Atmospheric Aerosols  

E-Print Network (OSTI)

HULIS) in biomass-burning aerosols, Atmospheric Chemistrymicroscopical and aerosol dynamical characterizationof soot aerosols, Journal of Aerosol Science , 34 , 1347-

Hopkins, Rebecca J.; Tivanski, Alexei V.; Marten, Bryan D.; Gilles, Mary K.

2007-01-01T23:59:59.000Z

280

Photometric Variations as Small Perturbations in Aerosol Content  

NLE Websites -- All DOE Office Websites (Extended Search)

Photometric Variations as Photometric Variations as Small Perturbations in Aerosol Content I. Musat Department of Meteorology University of Maryland College Park, Maryland R. G. Ellingson Department of Meteorology Florida State University Tallahassee, Florida Abstract The quality of profile fitting of resolved stars depends ultimately upon the accuracy with which spectral differences of the sources are retrievable within the data, because the radiation color of well-separated known sources can serve as an indicator of the origin of the optical depth variations one observes during the night. The particularities of the whole sky imager (WSI) detector and optical system are such that the data suffer from lack of the spatial resolution required in a common astronomical observation.

Note: This page contains sample records for the topic "aerosol observing systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Development of Soft Ionization for Particulate Organic Detection with the Aerodyne Aerosol Mass Spectrometer  

SciTech Connect

During this DOE SBIR Phase II project, we have successfully developed several soft ionization techniques, i.e., ionization schemes which involve less fragmentation of the ions, for use with the Aerodyne time-of-flight aerosol mass spectrometer (ToF-AMS). Vacuum ultraviolet single photon ionization was demonstrated in the laboratory and deployed in field campaigns. Vacuum ultraviolet single photon ionization allows better identification of organic species in aerosol particles as shown in laboratory experiments on single component particles, and in field measurements on complex multi-component particles. Dissociative electron attachment with lower energy electrons (less than 30 eV) was demonstrated in the measurement of particulate organics in chamber experiments in Switzerland, and is now a routine approach with AMS systems configured for bipolar, negative ion detection. This technique is particularly powerful for detection of acidic and other highly oxygenated secondary organic aerosol (SOA) chemical functionality. Low energy electron ionization (10 to 12 eV) is also a softer ionization approach routinely available to AMS users. Finally, Lithium ion attachment has been shown to be sensitive to more alkyl-like chemical functionality in SOA. Results from Mexico City are particularly exciting in observing changes in SOA molecular composition under different photochemical/meteorological conditions. More recent results detecting biomass burns at the Montana fire lab have demonstrated quantitative and selective detection of levoglucosan. These soft ionization techniques provide the ToF-AMS with better capability for identifying organic species in ambient atmospheric aerosol particles. This, in turn, will allow more detailed study of the sources, transformations and fate of organic-containing aerosol.

Trimborn, A; Williams, L R; Jayne, J T; Worsnop, D R

2008-06-19T23:59:59.000Z

282

Wavelength Dependence of the Absorption of Black Carbon Particles: Predictions and Results from the TARFOX Experiment and Implications for the Aerosol Single Scattering Albedo  

Science Conference Proceedings (OSTI)

Measurements are presented of the wavelength dependence of the aerosol absorption coefficient taken during the Tropical Aerosol Radiative Forcing Observational Experiment (TARFOX) over the northern Atlantic. The data show an approximate ??1 ...

Robert W. Bergstrom; Philip B. Russell; Phillip Hignett

2002-02-01T23:59:59.000Z

283

Sources and production of organic aerosol in Mexico City: insights from the combination of a chemical transport model (PMCAMx-2008) and measurements  

E-Print Network (OSTI)

Urban areas are large sources of organic aerosols and their precursors. Nevertheless, the contributions of primary (POA) and secondary organic aerosol (SOA) to the observed particulate matter levels have been difficult to ...

Tsimpidi, A. P.

284

Aerosols in a Changing Atmosphere: From Detailed Aerosol Microphysics to  

NLE Websites -- All DOE Office Websites (Extended Search)

Aerosols in a Changing Atmosphere: From Detailed Aerosol Microphysics to Aerosols in a Changing Atmosphere: From Detailed Aerosol Microphysics to Policy Applications Speaker(s): Susanne Bauer Date: December 6, 2011 - 4:00pm Location: 90-4133 Seminar Host/Point of Contact: Surabi Menon The anthropogenic increase in aerosol concentrations since preindustrial times and its net cooling effect on the atmosphere is thought to mask some of the greenhouse gas induced warming. Although the overall effect of aerosols on solar radiation and clouds is most certainly negative, some individual forcing agents and feedbacks have positive forcing effects. Recent studies have tried to identify some of those positive forcing agents and their individual emission sectors, However, understanding the net effect of multi-source emitting sectors and the involved cloud feedbacks is

285

Assimilation of Standard and Targeted Observations within the Unstable Subspace of the ObservationAnalysisForecast Cycle System  

Science Conference Proceedings (OSTI)

In this paper it is shown that the flow-dependent instabilities that develop within an observationanalysisforecast (OAF) cycle and that are responsible for the background error can be exploited in a very simple way to assimilate observations. ...

Anna Trevisan; Francesco Uboldi

2004-01-01T23:59:59.000Z

286

Aircraft Observations of Convective Systems in the Indian Ocean [EVS Event]  

NLE Websites -- All DOE Office Websites (Extended Search)

Aircraft Observations of Convective Systems in the Indian Ocean Aircraft Observations of Convective Systems in the Indian Ocean August 23, 2013 Speaker: Bradley Nicholas Guy National Research Council Postdoctoral Fellow NOAA National Severe Storms Laboratory Date: Friday, August 23, 2013 Time: 11:00 a.m. Location: Argonne National Laboratory TCS Building 240 Room 4301 In the DYNAMO (Dynamics of the Madden-Julian Oscillation) field experiment, a large number of measurement platforms were deployed to study environmental and convective cloud system characteristics of the Madden-Julian Oscillation (MJO) initiation region in the Indian Ocean. A mobile platform, the NOAA P-3 instrumented aircraft, sampled intense convective cloud systems, along with the surrounding environment. This presentation will explore the characteristics of mesoscale convective

287

THE ROLE OF SOOT IN AEROSOL CHEMISTRY  

E-Print Network (OSTI)

characterization of aerosols." in Nature. Aim. and MethodsLAWRENCE THE ROLE OF SOOT IN AEROSOL CHEMISTRY T. NovakovTHE ROLE OF SOOT IN AEROSOL CHEMISTRY* T. Novakov Lawrence

Novakov, T.

2010-01-01T23:59:59.000Z

288

Characterizing the formation of secondary organic aerosols  

E-Print Network (OSTI)

and Flagan, R.C. (1990) Aerosol Sci. and Technol. 13 , 230.and Seinfeld, J.H. (2002) Aerosol Science and Technology ,light absorption by atmospheric aerosol, in preparation for

Lunden, Melissa; Black, Douglas; Brown, Nancy

2004-01-01T23:59:59.000Z

289

Optical Properties of Secondary Organic Aerosols  

E-Print Network (OSTI)

Paulson, S. E. ; Chung, A. Aerosol Sci. Technol. 2007 , 41,Y. G. ; Daum, P. H. J. Aerosol Sci 2008 , 39, 974-986. (32)Accurate Monitoring of Terrestrial Aerosols and Total Solar

Kim, Hwajin

2012-01-01T23:59:59.000Z

290

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

DOE Data Explorer (OSTI)

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

Chitra Sivaraman; Connor Flynn

291

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

SciTech Connect

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

Chitra Sivaraman; Connor Flynn

2010-12-15T23:59:59.000Z

292

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

NLE Websites -- All DOE Office Websites (Extended Search)

govCampaignsBiogenic Aerosols - Effects on Clouds and Climate: Snowfall govCampaignsBiogenic Aerosols - Effects on Clouds and Climate: Snowfall Experiment 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 Description The snowfall measurement campaign, which will take place during AMF2 deployment in Finland, will focus on understanding snowfall microphysics and characterizing performance of surface based snowfall measurement instruments. This will be achieved by combining triple frequency (X, Ka, W -band) radar observations of vertical structure of the precipitation,

293

Regional observations of mining blasts by the GSETT-3 seismic monitoring system  

SciTech Connect

The cessation of testing of any nuclear explosive devices in all environments is the goal of the Comprehensive Test Ban Treaty. In order to assure compliance with such a treaty, an international monitoring system has been proposed. This system will include seismic, infrasound, hydroacoustic and radionuclide monitors located throughout the world. The goal of this system is the detection of any nuclear test. In preparation for this treaty, a series of monitoring system tests, focusing primarily on seismic observations, have been undertaken. The most recent of these tests, Group of Scientific Experts Technical Test Three (GSETT-3), provides valuable data for assessing future monitoring systems. During the course of this experiment, seismic events associated with earthquakes, nuclear explosions and mining explosions have been recorded. This presentation will discuss the numbers and types of mining explosions triggering the system, in a particular area. Possible implications for the mining industry will be explored.

Stump, B.W.; Pearson, D.C.

1996-12-31T23:59:59.000Z

294

Aerosol Metrology for Climate Workshop  

Science Conference Proceedings (OSTI)

... the interaction of aerosols with solar radiation ... that will accelerate the development of new ... together experts from government, industry and academia ...

2012-04-26T23:59:59.000Z

295

Digital RAC with a disturbance observer for underwater vehicle-manipulator systems  

Science Conference Proceedings (OSTI)

Most control methods of underwater vehiclemanipulator systems (UVMS) are based on the computed torque method that is used for underwater robotic vehicles. We have proposed a resolved acceleration control (RAC) method for UVMS. In this article, we propose ... Keywords: Digital control, Disturbance observer, Manipulator, Underwater robot

Shinichi Sagara; Takashi Yatoh; Tomoaki Shimozawa

2010-12-01T23:59:59.000Z

296

Assimilation of Surface-Based Boundary Layer Profiler Observations during a Cool-Season Weather Event Using an Observing System Simulation Experiment. Part I: Analysis Impact  

Science Conference Proceedings (OSTI)

In this study, an Observing System Simulation Experiment was used to examine how the assimilation of temperature, water vapor, and wind profiles from a potential array of ground-based remote sensing boundary layer profiling instruments impacts the ...

Jason A. Otkin; Daniel C. Hartung; David D. Turner; Ralph A. Petersen; Wayne F. Feltz; Erik Janzon

2011-08-01T23:59:59.000Z

297

Long-term impacts of aerosols on vertical development of cloud and precipitation  

Science Conference Proceedings (OSTI)

Aerosols alter cloud density and the radiative balance of the atmosphere. This leads to changes in cloud microphysics and atmospheric stability, which can either suppress or foster the development of clouds and precipitation. The net effect is largely unknown, but depends on meteorological conditions and aerosol properties. Here, we examine the long-term impact of aerosols on the vertical development of clouds and rainfall frequencies, using a 10-year dataset of aerosol, cloud and meteorological variables collected in the Southern Great Plains in the United States. We show that cloud-top height and thickness increase with aerosol concentration measured near the ground in mixed-phase clouds-which contain both liquid water and ice-that have a warm, low base. We attribute the effect, which is most significant in summer, to an aerosol-induced invigoration of upward winds. In contrast, we find no change in cloud-top height and precipitation with aerosol concentration in clouds with no ice or cool bases. We further show that precipitation frequency and rain rate are altered by aerosols. Rain increases with aerosol concentration in deep clouds that have a high liquid-water content, but declines in clouds that have a low liquid-water content. Simulations using a cloud-resolving model confirm these observations. Our findings provide unprecedented insights of the long-term net impacts of aerosols on clouds and precipitation.

Li Z.; Liu Y.; Niu, F.; Fan, J.; Rosenfeld, D.; Ding, Y.

2011-11-13T23:59:59.000Z

298

Researchers Model Impact of Aerosols Over California  

NLE Websites -- All DOE Office Websites (Extended Search)

Researchers Model Impact of Aerosols Over California Researchers Model Impact of Aerosols Over California Research may clarify the effectiveness of regional pollution controls May...

299

Radar Observations of Convective System Variability in Relationship to African Easterly Waves during the 2006 AMMA Special Observing Period  

E-Print Network (OSTI)

A radar-based analysis of the structure, motion, and rainfall variability of westward-propagating squall-line mesoscale convective systems (SLMCSs) in Niamey, Niger, during the African Monsoon Multidisciplinary Activities ...

Williams, Earle R.

300

Radar Observations of Convective System Variability in Relationship to African Easterly Waves during the 2006 AMMA Special Observing Period  

Science Conference Proceedings (OSTI)

A radar-based analysis of the structure, motion, and rainfall variability of westward-propagating squall-line mesoscale convective systems (SLMCSs) in Niamey, Niger, during the African Monsoon Multidisciplinary Activities (AMMA) 2006 special ...

Rosana Nieto Ferreira; Thomas Rickenbach; Nick Guy; Earle Williams

2009-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol observing systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Sharp Observability Estimates for a System of Two Coupled Nonconservative Hyperbolic Equations  

SciTech Connect

We consider a system of two coupled nonconservative wave equations. For this system, we prove several observability estimates. Those observability estimates are sharp in the sense that they lead by duality to the controllability (exact or approximate) of the coupled system with a single control acting through one of the equations only while keeping the same controllability time as for a single equation. Existing results in the literature either require two controls, or in the case of a single control, they have a controllability time that blows up as the coupling parameter goes to zero. Our proofs rely on: (i) Carleman estimates, (ii) energy estimates and (iii) localizing arguments. The results obtained complement and improve, in some sense, earlier results while at the same time providing new uniqueness results.

Tebou, Louis, E-mail: teboul@fiu.edu [Florida International University, Department of Mathematics and Statistics (United States)

2012-10-15T23:59:59.000Z

302

Autonomous Observing and Control Systems for PAIRITEL, a 1.3m Infrared Imaging Telescope  

E-Print Network (OSTI)

The Peters Automated Infrared Imaging Telescope (PAIRITEL) is the first meter-class telescope operating as a fully robotic IR imaging system. Dedicated in October 2004, PAIRITEL began regular observations in mid-December 2004 as part of a 1.5 year commissioning period. The system was designed to respond without human intervention to new gamma-ray burst transients: this milestone was finally reached on November 9, 2005 but the telescope had a number of semi-automated sub-10 minute responses throughout early commissioning. When not operating in Target of Opportunity mode, PAIRITEL performs a number of queue scheduled transient monitoring campaigns. To achieve this level of automation, we have developed communicating tools to connect the various sub-systems: an intelligent queue scheduling database, run-time configurable observation sequence software, a data reduction pipeline, and a master state machine which monitors and controls all functions within and affecting the observatory.

J. S. Bloom; Dan L. Starr; Cullen H. Blake; M. F. Skrutskie; Emilio E. Falco

2005-11-30T23:59:59.000Z

303

Techniques for measuring atmospheric aerosols at the High Resolution Fly's Eye experiment  

E-Print Network (OSTI)

We describe several techniques developed by the High Resolution Fly's Eye experiment for measuring aerosol vertical optical depth, aerosol horizontal attenuation length, and aerosol phase function. The techniques are based on measurements of side-scattered light generated by a steerable ultraviolet laser and collected by an optical detector designed to measure fluorescence light from cosmic-ray air showers. We also present a technique to cross-check the aerosol optical depth measurement using air showers observed in stereo. These methods can be used by future air fluorescence experiments.

The HiRes Collaboration

2005-12-15T23:59:59.000Z

304

Organic Aerosol Partition Module Documentation  

Science Conference Proceedings (OSTI)

With the promulgation of new National Ambient Air Quality Standards (NAAQS) for fine particulate matter (PM-2.5), data and analytical tools are needed to support their implementation. This report documents an EPRI modeling component for efficiently simulating aspects of organic aerosol formation. Without this component, simulations would tend to overestimate the contribution of power plant emissions to atmospheric aerosol mass.

1999-07-14T23:59:59.000Z

305

Simulation of Aerosol-Cloud Interactions in the WRF Model at the Southern Great Plains Site  

E-Print Network (OSTI)

The aerosol direct and indirect effects were investigated for three specific cases during the March 2000 Cloud IOP at the SGP site by using a modified WRF model. The WRF model was previously altered to include a two-moment bulk microphysical scheme for the aerosol indirect effect and a modified Goddard shortwave radiation scheme for the aerosol direct effect. The three cases studied include a developing low pressure system, a low precipitation event of mainly cirrus clouds, and a cold frontal passage. Three different aerosol profiles were used with surface concentrations ranging from 210 cm-3 to 12,000 cm-3. In addition, each case and each aerosol profile was run both with and without the aerosol direct effect. Regardless of the case, increasing the aerosol concentration generally increased cloud water and droplet values while decreasing rain water and droplet values. Increased aerosols also decreased the surface shortwave radiative flux for every case; which was greatest when the aerosol direct effect was included. For convective periods during polluted model runs, the aerosol direct effect lowered the surface temperature and reduced convection leading to a lower cloud fraction. During most convective periods, the changes to cloud, rain, and ice water mixing ratios and number concentrations produced a nonlinear precipitation trend. A balance between these values was achieved for moderate aerosol profiles, which produced the highest convective precipitation rates. In non-convective cases, due to the presence of ice particles, aerosol concentration and precipitation amounts were positively correlated. The aerosol threshold between precipitation enhancement and suppression should be further studied for specific cloud types as well as for specific synoptic weather patterns to determine its precise values.

Vogel, Jonathan 1988-

2012-12-01T23:59:59.000Z

306

Transit Timing Observations from Kepler: IV. Confirmation of 4 Multiple Planet Systems by Simple Physical Models  

SciTech Connect

Eighty planetary systems of two or more planets are known to orbit stars other than the Sun. For most, the data can be sufficiently explained by non-interacting Keplerian orbits, so the dynamical interactions of these systems have not been observed. Here we present 4 sets of lightcurves from the Kepler spacecraft, which each show multiple planets transiting the same star. Departure of the timing of these transits from strict periodicity indicates the planets are perturbing each other: the observed timing variations match the forcing frequency of the other planet. This confirms that these objects are in the same system. Next we limit their masses to the planetary regime by requiring the system remain stable for astronomical timescales. Finally, we report dynamical fits to the transit times, yielding possible values for the planets masses and eccentricities. As the timespan of timing data increases, dynamical fits may allow detailed constraints on the systems architectures, even in cases for which high-precision Doppler follow-up is impractical.

Fabrycky, Daniel C.; /UC, Santa Cruz; Ford, Eric B.; /Florida U.; Steffen, Jason H.; /Fermilab; Rowe, Jason F.; /SETI Inst., Mtn. View /NASA, Ames; Carter, Joshua A.; /Harvard-Smithsonian Ctr. Astrophys.; Moorhead, Althea V.; /Florida U.; Batalha, Natalie M.; /San Jose State U.; Borucki, William J.; /NASA, Ames; Bryson, Steve; /NASA, Ames; Buchhave, Lars A.; /Bohr Inst. /Copenhagen U.; Christiansen, Jessie L.; /SETI Inst., Mtn. View /NASA, Ames /Caltech

2012-01-01T23:59:59.000Z

307

Evaluating the Cloud Cover Forecast of NCEP Global Forecast System with Satellite Observation  

E-Print Network (OSTI)

To assess the quality of daily cloud cover forecast generated by the operational global numeric model, the NCEP Global Forecast System (GFS), we compose a large sample with outputs from GFS model and satellite observations from the International Satellite Cloud Climatology Project (ISCCP) in the period of July 2004 to June 2008, to conduct a quantitative and systematic assessment of the performance of a cloud model that covers a relatively long range of time, basic cloud types, and in a global view. The evaluation has revealed the goodness of the model forecast, which further illustrates our completeness on understanding cloud generation mechanism. To quantity the result, we found a remarkably high correlation between the model forecasts and the satellite observations over the entire globe, with mean forecast error less than 15% in most areas. Considering a forecast within 30% difference to the observation to be a "good" one, we find that the probability for the GFS model to make good forecasts varies between...

Ye, Quanzhi

2011-01-01T23:59:59.000Z

308

Multiwavelength optical observations of the chromospherically active binary system MS Ser  

E-Print Network (OSTI)

We present here a continuation of our ongoing project of multiwavelength optical observations aimed at studying the chromosphere of active binary systems using the information provided for several optical spectroscopic features that are formed at different heights in the chromosphere (Montes et al. 1997, 1998; Sanz-Forcada et al. 1998). In this contribution we focus our study on the preliminar analysis of the active binary system MS Ser. We have taken H$\\alpha$ and H$\\beta$ spectra in 1995 with the Coude Spectrograph at 2.2m telescope in Calar Alto, and high resolution SOFIN echelle spectra (covering H_alpha, H_beta, Na I D_{1} and D_{2}, He I D_{3}, Mg I b triplet, Ca II H & K, and Ca II infrared triplet lines) in 1998 with the 2.56m Nordic Optical Telescope (NOT) in La Palma. A strong emission in the Ca II H & K and Ca II IRT lines, coming from the primary component (recently classified as K2IV) is observed. One of the Ca II H & K spectra (at orbital phase near quadrature) reveals that the secondary (G8V) also exhibit a small emission. A near complete and variable filling-in of the H_alpha and H_beta is obtained after the application of the spectral subtraction technique. We detect also some seasonal variations between these two observing runs and in comparation with our previous Ca II H & K observations taken in 1993 (Montes et al. 1995).

J. Sanz-Forcada; D. Montes; M. J. Fernandez-Figueroa; E. De Castro; M. Cornide

1998-09-09T23:59:59.000Z

309

Nanomaterials from Aerosols Aerosols are suspensions of liquid or solid particles in a gas. Aerosol particles  

E-Print Network (OSTI)

arid regions in China and Africa. Such aerosol streams have been shown to travel around the globe with silica aerosols from China impacting air quality in the continental US and #12;2 alumina and titania delivery mechanisms for a variety of drugs as an alternative to injections. As delivery devices

Beaucage, Gregory

310

The effect of roughness on aerosol deposition in tubes  

E-Print Network (OSTI)

Experimental measurements of simulated roughness within tubes and the subsequent aerosol penetration performance through these tubes were conducted for a aerosol particle size range of 5 nm to 20 nm and a flow rate range of 28 L/min to 169.9 L/min. The relative roughness for each of the tubes tested are as follows: clean aluminum pipe and clean copper tube, F,/D = 10-4; fine sandpaper pipe, F,/D = 0.017-12 helical ridges per linear centimeter copper tube, F,/D = 0.046; coarse sandpaper pipe, F,/D = 0.065. Non-dimensional quantities were used to produce an empirical model relating roughness to aerosol penetration. The dependent variable, aerosol penetration, was encompassed in the non-dimensional deposition velocity (v,) and modeled as a function of the dependent variables, non-dimensional particle relaxation time (,c,) and relative roughness (&/D). In addition, a method was developed for estimating when to remove the sampling transport lines for cleaning due to the roughness within the transport line. The empirical correlation fits the data over the range of 0. I 6 to 112 L/min. For these conditions, the model deviated from the experimental data by less than 10% with one outlier which deviated by 20% for the coarse sandpaper pipe at a flow rate of 1 12 L/min. The correlation was used to show that the transport lines should be removed for cleaning or replacement once the pressure drop has exceeded 7.5 mm Hg. The experimental data has shown that the aerosol penetration decreases below 85% for an internal roughness comparable to this pressure drop limit. The correlation for aerosol penetration in transport lines with internal roughness presented should be a beneficial engineering tool for predicting the aerosol losses in sampling systems where roughness is a concern. The correlation should be a useful sub-model for aerosol penetration prediction computational tools as well.

Chavez, Mario Cesar

1997-01-01T23:59:59.000Z

311

Deliquescence properties and particle size change of hygroscopic aerosols  

DOE Green Energy (OSTI)

Ambient aerosols frequently contain large proportions of hygroscopic inorganic salts such as sulfates and nitrates, which may induce adverse health effects upon inhalation. The inhaled salt particles are invariably exposed to a humid environment; their deposition along the respiratory tract will necessarily depend upon the size change resulting from water vapor condensation. This paper discusses the deliquescent properties of pure and mixed salt aerosols and the particle size change as a function of relative humidity. Experimental results are presented for the growth of mixed chlorides (NaCl-KCl), mixed sulfates (H{sub 2}SO{sub 4}-(NH{sub 4}){sub 2}SO{sub 4}), and mixed (NH/sub 4/){sub 2}SOsub 4}-NH{sub 4}NO{sub 3} aerosol systems. It is shown that the behavior of the mixed salt aerosols in a moist atmosphere can be predicted from phase diagrams and pertinent thermodynamic properties of the bulk solutions. The evaporation of a saline droplet in an atmosphere of decreasing humidities is also investigated experimentally. For each deliquescent salt aerosol, there is a threshold humidity below which the solution droplets will quickly evaporate to become crystalline particles. The information is useful in the selection of a suitable humidification procedure to generate test aerosols for exposure studies.

Tang, I.N.

1979-01-01T23:59:59.000Z

312

Evolution of Asian aerosols during transpacific transport in INTEX-B  

Science Conference Proceedings (OSTI)

Measurements of aerosol composition were made with an Aerodyne High Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) on board the NSF/NCAR C-130 aircraft as part of the Intercontinental Chemical Transport Experiment Phase B 5 (INTEX-B) field campaign over the Eastern Pacific Ocean. The HR-ToF-AMS measurements of non-refractory submicron aerosol mass are shown to compare well with other aerosol instrumentation in the INTEX-B field study. Two case studies are described for pollution layers transported across the Pacific from the Asian continent, intercepted 34 days and 710 days downwind of Asia, respectively. Aerosol chemistry is shown to 10 be a robust tracer for air masses originating in Asia, specifically the presence of sulfate dominated aerosol is a distinguishing feature of Asian pollution layers that have been transported to the Eastern Pacific. We examine the time scales of processing for sulfate and organic aerosol in the atmosphere and show that our observations confirm a conceptual model for transpacific transport from Asia proposed by Brock et al. (2004). 15 Our observations of both sulfate and organic aerosol in aged Asian pollution layers are consistent with fast formation near the Asian continent, followed by washout during lofting and subsequent transformation during transport across the Pacific. Our observations are the first atmospheric measurements to indicate that although secondary organic aerosol (SOA) formation from pollution happens on the timescale of one day, 20 the oxidation of organic aerosol continues at longer timescales in the atmosphere. Comparisons with chemical transport models of data from the entire campaign reveal an under-prediction of SOA mass in the MOZART model, but much smaller discrepancies with the GEOS-Chem model than found in previous studies over the Western Pacific. No evidence is found to support a previous hypothesis for significant secondary 25 organic aerosol formation in the free troposphere.

Dunlea, E. J.; DeCarlo, Peter; Aiken, Allison; Kimmel, Joel; Peltier, R. E.; Weber, R. J.; Tomlinson, Jason M.; Collins, Donald R.; Shinozuka, Yohei; McNaughton, C. S.; Howell, S. G.; Clarke, A. D.; Emmons, L.; Apel, Eric; Pfister, G. G.; van Donkelaar, A.; Martin, R. V.; Millet, D. B.; Heald, C. L.; Jimenez, J. L.

2009-10-01T23:59:59.000Z

313

On the Importance of Organic Oxygen for Understanding OrganicAerosol Particles  

SciTech Connect

This study shows how aerosol organic oxygen data could provide new information about organic aerosol mass, aqueous solubility of organic aerosols, formation of secondary organic aerosol (SOA) and the relative contributions of anthropogenic and biogenic sources. For more than two decades atmospheric aerosol organic mass (OM) concentration has been estimated by multiplying the measured carbon content by an assumed (OM)-to-organic carbon (OC) factor, usually 1.4. However, this factor can vary from 1.0 to 2.5 depending on location. This large uncertainty about aerosol organic mass limits our understanding of the influence of organic aerosol on climate, visibility and health. New examination of organic aerosol speciation data shows that the oxygen content is responsible for the observed range in the OM-to-OC factor. When organic oxygen content is excluded, the ratio of non-oxygen organic mass to carbon mass varies very little across different environments (1.12 to 1.14). The non-oxygen-OM-to-OC factor for all studied sites (urban and non-urban) averaged 1.13. The uncertainty becomes an order of magnitude smaller than the uncertainty in the best current estimates of organic mass to organic carbon ratios (1.6 {+-} 0.2 for urban and 2.1 {+-} 0.2 for non-urban areas). This analysis suggests that, when aerosol organic oxygen data become available, organic aerosol mass can be quite accurately estimated using just OC and organic oxygen (OO) without the need to know whether the aerosol is fresh or aged. In addition, aerosol organic oxygen data will aid prediction of water solubility since compounds with OO-to-OC higher than 0.4 have water solubilities higher than 1 g per 100 g water.

Pang, Y.; Turpin, B.J.; Gundel, L.A.

2005-04-01T23:59:59.000Z

314

Dust Aerosol Impact on North Africa Climate: A GCM Investigation of Aerosol-Cloud-Radiation Interactions Using A-Train Satellite Data  

Science Conference Proceedings (OSTI)

The climatic effects of dust aerosols in North Africa have been investigated using the atmospheric general circulation model (AGCM) developed at the University of California, Los Angeles (UCLA). The model includes an efficient and physically based radiation parameterization scheme developed specifically for application to clouds and aerosols. Parameterization of the effective ice particle size in association with the aerosol indirect effect based on cloud and aerosol data retrieved from A-Train satellite observations have been employed in the climate model simulations. Offline simulations reveal that the direct solar, IR, and net forcings by dust aerosols generally increase with increasing aerosol optical depth (AOD). When the dust semi-direct effect is included with the presence of ice clouds, positive IR radiative forcing is enhanced, since ice clouds trap substantial IR radiation, while the positive solar forcing with dust aerosols alone has been changed to negative values due to the strong reflection of solar radiation by clouds, indicating that cloud forcing could exceed aerosol forcing. With the aerosol indirect effect, the net cloud forcing is generally reduced for ice water path (IWP) larger than 20 g m-2. The magnitude of the reduction increases with IWP. AGCM simulations show that the reduced ice crystal mean effective size due to the aerosol first indirect effect result in less OLR and net solar flux at the top of the atmosphere over the cloudy area of the North Africa region because ice clouds with smaller size trap more IR radiation and reflect more solar radiation. The precipitation in the same area, however, increases due to the aerosol indirect effect on ice clouds, corresponding to the enhanced convection as indicated by reduced OLR. The increased precipitation seems to be associated with enhanced ice water contents in this region. The 200 mb radiative heating rate shows more cooling with the aerosol indirect effect since greater cooling is produced at the cloud top with smaller ice crystal size. The 500 mb omega indicates strong upward motion, which, together with the increased cooling effect, results in the increased ice water contents. Adding the aerosol direct effect into the model simulation reduces the precipitation in the normal rainfall band over North Africa, where precipitation is shifted to the south and the northeast produced by the absorption of sunlight and the subsequent heating of the air column by dust particles. As a result, rainfall is drawn further inland to the northeast. This study represents the first attempt to quantify the climate impact of aerosol indirect effect using a GCM in connection with A-train satellite data. The parameterization for the aerosol first indirect effect developed in this study can be readily incorporated for application to any other GCMs.

Gu, Y.; Liou, K. N.; Jiang, Jonathan; Su, Hui; Liu, Xiaohong

2012-02-15T23:59:59.000Z

315

Raman lidar profiling of aerosols over the central U.S.; diurnal  

E-Print Network (OSTI)

We use profiles of aerosol extinction, water vapor mixing ratio, and relative humidity measured by the ARM SGP Raman lidar in northern Oklahoma to show how the vertical distributions of aerosol extinction and water vapor vary throughout the diurnal cycle. While significant (20-30%) variations in aerosol extinction occurred near the surface as well as aloft, smaller (~10%) variations were observed in the diurnal variability of aerosol optical thickness (AOT). The diurnal variations in aerosol extinction profiles are well correlated with corresponding variations in the average relative humidity profiles. The water vapor mixing ratio profiles and integrated water vapor amounts generally show less diurnal variability. The Raman lidar profiles are also used to evaluate the aerosol optical thickness and aerosol extinction profiles simulated by the GOCART global aerosol model. Initial comparisons show that the AOT simulated by GOCART was in closer agreement with the AOT derived from the Raman lidar and Sun photometer measurements during November 2000 than during September 2000. For both months, the vertical variability in average aerosol extinction profiles simulated by GOCART is less than the variability in the corresponding Raman lidar profiles.

Variability And Comparisons; R. A. Ferrare A; M. Chin B; M. Clayton C; D. Turner D

2002-01-01T23:59:59.000Z

316

Relating Secondary Organic Aerosol Characteristics with Cloud Condensation Nuclei Activity  

E-Print Network (OSTI)

and microphysical characterization of ambient aerosols withthe aerodyne aerosol mass spectrometer, Mass Spectrom Rev,of secondary organic aerosol under near atmospheric

Tang, Xiaochen

2013-01-01T23:59:59.000Z

317

Soft ionization of thermally evaporated hypergolic ionic liquid aerosols  

E-Print Network (OSTI)

+ ][Dca ? ]. Figure 2. Aerosol particle size distribution ofhypergolic ionic liquid aerosols Christine J. Koh , Chen-ionization of evaporated IL aerosols Isolated ion pairs of a

Koh, Christine J.

2013-01-01T23:59:59.000Z

318

ATMOSPHERIC AEROSOL RESEARCH ANNUAL REPORT 1975-76  

E-Print Network (OSTI)

this room ATMOSPHERIC AEROSOL RESEARCH -RECEIVED I.AWSSKCEDIVISION ATMOSPHERIC AEROSOL RESEARCH ANNUAL REPORTMass and Composition of Aerosol as a Function of Time,

Novakov, T.

2010-01-01T23:59:59.000Z

319

Aerosol measurements with laser-induced breakdown spectroscopy  

E-Print Network (OSTI)

anthropogenic sulfate aerosols. Tellus, Ser. A, vol. 43, p.Twomey, Atmospheric Aerosols. New York : Elsevier ScientificCo. , 45. B.A. Albrecht, Aerosols, cloud microphysics, and

Lithgow, Gregg Arthur

2007-01-01T23:59:59.000Z

320

ATMOSPHERIC AEROSOL RESEARCH, ANNUAL REPORT 1976-77  

E-Print Network (OSTI)

DIVISION ATMOSPHERIC AEROSOL RESEARCH ANNUAL REPORTLow-Z Elements in Atmospheric Aerosol Particles by Nuclearof sulfur dioxide by aerosols of manganese sulfate," Ind.

Novakov, T.

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol observing systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Black carbon aerosols and the third polar ice cap  

E-Print Network (OSTI)

estimations in global aerosol models, Atmos. Chem. Phys. ,Cloud mi- crophysics and aerosol indirect efefcts in theuncertainties in assessing aerosol effects on climate, Ann.

Menon, Surabi

2010-01-01T23:59:59.000Z

322

Total aerosol effect: forcing or radiative flux perturbation?  

E-Print Network (OSTI)

of the ?rst indirect aerosol effect, Atmos. Chem. Phys. , 5,Cloud susceptibility and the ?rst aerosol indirect forcing:to black carbon and aerosol concentrations, J. Geophys.

Lohmann, Ulrike

2010-01-01T23:59:59.000Z

323

Sensor Configuration Selection for Discrete-Event Systems under Unreliable Observations  

SciTech Connect

Algorithms for counting the occurrences of special events in the framework of partially-observed discrete event dynamical systems (DEDS) were developed in previous work. Their performances typically become better as the sensors providing the observations become more costly or increase in number. This paper addresses the problem of finding a sensor configuration that achieves an optimal balance between cost and the performance of the special event counting algorithm, while satisfying given observability requirements and constraints. Since this problem is generally computational hard in the framework considered, a sensor optimization algorithm is developed using two greedy heuristics, one myopic and the other based on projected performances of candidate sensors. The two heuristics are sequentially executed in order to find best sensor configurations. The developed algorithm is then applied to a sensor optimization problem for a multiunit- operation system. Results show that improved sensor configurations can be found that may significantly reduce the sensor configuration cost but still yield acceptable performance for counting the occurrences of special events.

Wen-Chiao Lin; Tae-Sic Yoo; Humberto E. Garcia

2010-08-01T23:59:59.000Z

324

GCM Aerosol Radiative Effects Using Geographically Varying Aerosol Sizes Deduced from AERONET Measurements  

Science Conference Proceedings (OSTI)

Aerosol optical properties, and hence the direct radiative effects, are largely determined by the assumed aerosol size distribution. In order to relax the fixed aerosol size constraint commonly used in general circulation models (GCMs), ...

Glen Lesins; Ulrike Lohmann

2003-11-01T23:59:59.000Z

325

Downscaling Aerosols and the Impact of Neglected Subgrid Processes on Direct Aerosol Radiative Forcing for a Representative Global Climate Model Grid Spacing  

Science Conference Proceedings (OSTI)

Recent improvements to many global climate models include detailed, prognostic aerosol calculations intended to better reproduce the observed climate. However, the trace gas and aerosol fields are treated at the grid-cell scale with no attempt to account for sub-grid impacts on the aerosol fields. This paper begins to quantify the error introduced by the neglected sub-grid variability for the shortwave aerosol radiative forcing for a representative climate model grid spacing of 75 km. An analysis of the value added in downscaling aerosol fields is also presented to give context to the WRF-Chem simulations used for the sub-grid analysis. We found that 1) the impact of neglected sub-grid variability on the aerosol radiative forcing is strongest in regions of complex topography and complicated flow patterns, and 2) scale-induced differences in emissions contribute strongly to the impact of neglected sub-grid processes on the aerosol radiative forcing. The two of these effects together, when simulated at 75 km vs. 3 km in WRF-Chem, result in an average daytime mean bias of over 30% error in top-of-atmosphere shortwave aerosol radiative forcing for a large percentage of central Mexico during the MILAGRO field campaign.

Gustafson, William I.; Qian, Yun; Fast, Jerome D.

2011-07-13T23:59:59.000Z

326

Evolution of Ozone, Particulates, and Aerosol Direct Radiative Forcing in the Vicinity of Houston Using a Fully Coupled Meteorology-Chemistry-Aerosol Model  

SciTech Connect

A new fully-coupled meteorology-chemistry-aerosol model is used to simulate the urban to regional scale variations in trace gases, particulates, and aerosol direct radiative forcing in the vicinity of Houston over a five day summer period. Model performance is evaluated using a wide range of meteorological, chemistry, and particulate measurements obtained during 2000 Texas Air Quality Study. The predicted trace gas and particulate distributions were qualitatively similar to the surface and aircraft measurements with considerable spatial variations resulting from urban, power plant, and industrial sources of primary pollutants. Sulfate, organic carbon, and other inorganics were the largest constituents of the predicted particulates. The predicted shortwave radiation was 30 to 40 W m-2 closer to the observations when the aerosol optical properties were incorporated into the shortwave radiation scheme; however, the predicted hourly aerosol radiative forcing was still under-estimated by 10 to 50 W m-2. The predicted aerosol radiative forcing was larger over Houston and the industrial ship channel than over the rural areas, consistent with surface measurements. The differences between the observed and simulated aerosol radiative forcing resulted from transport errors, relative humidity errors in the upper convective boundary layer that affect aerosol water content, secondary organic aerosols that were not yet included in the model, and uncertainties in the primary particulate emission rates. The current model was run in a predictive mode and demonstrates the challenges of accurately simulating all of the meteorological, chemical, and aerosol parameters over urban to regional scales that can affect aerosol radiative forcing.

Fast, Jerome D.; Gustafson, William I.; Easter, Richard C.; Zaveri, Rahul A.; Barnard, James C.; Chapman, Elaine G.; Grell, Georg; Peckham, S. E.

2006-11-11T23:59:59.000Z

327

Sealing Ducts in Large Commercial Buildings with Aerosolized Sealant Particles  

NLE Websites -- All DOE Office Websites (Extended Search)

2414 2414 1 Sealing Ducts in Large Commercial Buildings with Aerosolized Sealant Particles M. P. Modera, O. Brzozowski ** , F. R. Carrié * , D. J. Dickerhoff, W. W. Delp, W. J. Fisk, R. Levinson, D. Wang Abstract Electricity energy savings potential by eliminating air leakage from ducts in large commercial buildings is on the order of 10 kWh/m 2 per year (1 kWh/ft 2 ). We have tested, in two large commercial buildings, a new technology that simultaneously seals duct leaks and measures effective leakage area of ducts. The technology is based upon injecting a fog of aerosolized sealant particles into a pressurized duct system. In brief, this process involves blocking all of the intentional openings in a duct system (e.g., diffusers). Therefore, when the system is pressurized, the only place for the air carrying the aerosol

328

Effect of Aerosol on Circulations and Precipitation in Deep Convective Clouds  

Science Conference Proceedings (OSTI)

This study examines the effect of a mesoscale perturbation of aerosol on a larger-scale cloud system driven by deep convective clouds. An aerosol-perturbed domain of size 120 km is prescribed in the middle of the larger-scale domain of size 1100 ...

Seoung Soo Lee

2012-06-01T23:59:59.000Z

329

Analyzing signatures of aerosol-cloud interactions from satellite retrievals and the GISS GCM to constrain the aerosol indirect effect  

E-Print Network (OSTI)

dust, and pollution aerosol on shallow cloud developmentclouds on indirect aerosol climate forcing, Nature, 432,1014 Albrecht, B. A. , Aerosols, cloud microphysics, and

2008-01-01T23:59:59.000Z

330

The effect of aerosol vertical profiles on satellite-estimated surface particle sulfate concentrations  

SciTech Connect

The aerosol vertical distribution is an important factor in determining the relationship between satellite retrieved aerosol optical depth (AOD) and ground-level fine particle pollution concentrations. We evaluate how aerosol profiles measured by ground-based lidar and simulated by models can help improve the association between AOD retrieved by the Multi-angle Imaging Spectroradiometer (MISR) and fine particle sulfate (SO4) concentrations using matched data at two lidar sites. At the Goddard Space Flight Center (GSFC) site, both lidar and model aerosol profiles marginally improve the association between SO4 concentrations and MISR fractional AODs, as the correlation coefficient between cross-validation (CV) and observed SO4 concentrations changes from 0.87 for the no-scaling model to 0.88 for models scaled with aerosol vertical profiles. At the GSFC site, a large amount of urban aerosols resides in the well-mixed boundary layer so the column fractional AODs are already excellent indicators of ground-level particle pollution. In contrast, at the Atmospheric Radiation Measurement Program (ARM) site with relatively low aerosol loadings, scaling substantially improves model performance. The correlation coefficient between CV and observed SO4 concentrations is increased from 0.58 for the no-scaling model to 0.76 in the GEOS-Chem scaling model, and the model bias is reduced from 17% to 9%. In summary, despite the inaccuracy due to the coarse horizontal resolution and the challenges of simulating turbulent mixing in the boundary layer, GEOS-Chem simulated aerosol profiles can still improve methods for estimating surface aerosol (SO4) mass from satellite-based AODs, particularly in rural areas where aerosols in the free troposphere and any long-range transport of aerosols can significantly contribute to the column AOD.

Liu, Yang; Wang, Zifeng; Wang, Jun; Ferrare, Richard A.; Newsom, Rob K.; Welton, Ellsworth J.

2011-02-15T23:59:59.000Z

331

Time Series of Aerosol Column Optical Depth at the Barrow, Alaska, ARM Climate Research Facility for 2008 Fourth Quarter 2009 ARM and Climate Change Prediction Program Metric Report  

Science Conference Proceedings (OSTI)

The uncertainties in current estimates of anthropogenic radiative forcing are dominated by the effects of aerosols, both in relation to the direct absorption and scattering of radiation by aerosols and also with respect to aerosol-related changes in cloud formation, longevity, and microphysics (See Figure 1; Intergovernmental Panel on Climate Change, Assessment Report 4, 2008). Moreover, the Arctic region in particular is especially sensitive to changes in climate with the magnitude of temperature changes (both observed and predicted) being several times larger than global averages (Kaufman et al. 2009). Recent studies confirm that aerosol-cloud interactions in the arctic generate climatologically significant radiative effects equivalent in magnitude to that of green house gases (Lubin and Vogelmann 2006, 2007). The aerosol optical depth is the most immediate representation of the aerosol direct effect and is also important for consideration of aerosol-cloud interactions, and thus this quantity is essential for studies of aerosol radiative forcing.

C Flynn; AS Koontz; JH Mather

2009-09-01T23:59:59.000Z

332

Design of a Real-Time Scanning Electrical Mobility Spectrometer and its Application in Study of Nanoparticle Aerosol Generation  

E-Print Network (OSTI)

A real-time, mobile Scanning Electrical Mobility Spectrometer (SEMS) was designed using a Condensation Particle Counter (CPC) and Differential Mobility Analyzer (DMA) to measure the size distribution of nanoparticles. The SEMS was calibrated using monodisperse Polystyrene Latex (PSL) particles, and was then applied to study the size distribution of TiO2 nanoparticle aerosols generated by spray drying water suspensions of the nanoparticles. The nanoparticle aerosol size distribution, the effect of surfactant, and the effect of residual solvent droplets were determined. The SEMS system was designed by integrating the Electrical System, the Fluid Flow System, and the SEMS Software. It was calibrated using aerosolized Polystyrene Latex (PSL) spheres with nominal diameters of 99 nm and 204 nm. TiO2 nanoparticle aerosols were generated by atomizing water suspensions of TiO2 nanoparticles using a Collison nebulizer. Size distribution of the TiO2 aerosol was measured by the SEMS, as well as by TEM. Furthermore, the effect of surfactant, Tween 20 at four different concentrations between 0.01mM and 0.80mM, and stability of aerosol concentration with time were studied. It was hypothesized that residual particles in DI water observed during the calibration process were a mixture of impurities in water and unevaporated droplets. Solid impurities were captured on TEM grids using a point-to-plane Electrostatic Precipitator (ESP) and analyzed by Energy Dispersive Spectroscopy (EDS) while the contribution of unevaporated liquid droplets to residual particles was confirmed by size distribution measurements of aerosolized DI water in different humidity conditions. The calibration indicated that the mode diameter was found to be at 92.5nm by TEM and 95.8nm by the SEMS for 99nm nominal diameter particles, a difference of 3.6%. Similarly, the mode diameter for 204nm nominal diameter particles was found to be 194.9nm by TEM and 191nm by SEMS, a difference of 2.0%. Measurements by SEMS for TiO2 aerosol generated by Collison nebulizer indicated the mode diameters of 3mM, 6mM, and 9mM concentrations of TiO2 suspension to be 197.5nm, 200.0nm and 195.2nm respectively. On the other hand, the mode diameter was found to be approximately 95nm from TEM analysis of TiO2 powder. Additionally, concentration of particles generated decreased with time. Dynamic Light Scattering (DLS) measurements indicated agglomeration of particles in the suspension. Furthermore, the emulation of single particle distribution was not possible even after using Tween 20 in concentrations between 0.01mM and 0.80mM. From the study of residual particles in DI water, it was found that residual particles observed during the aerosolization of suspensions of DI water were composed of impurities present in DI water and unevaporated droplets of DI water. Although it was possible to observe solid residual particles on the TEM grid, EDS was not able to determine the chemical composition of these particles.

Singh, Gagan

2010-05-01T23:59:59.000Z

333

Wind Measurement and Archival under the Automated Surface Observing System (ASOS): User Concerns and Opportunity for Improvement  

Science Conference Proceedings (OSTI)

The National Weather Service, as a part of its modernization effort, is implementing the Automated Surface Observing System (ASOS). Much discussion has occurred about various aspects of ASOS versus the current system of manual and automated ...

Mark D. Powell

1993-04-01T23:59:59.000Z

334

Developing an Operational, Surface-Based, GPS, Water Vapor Observing System for NOAA: Network Design and Results  

Science Conference Proceedings (OSTI)

The need for a reliable, low-cost observing system to measure water vapor in the atmosphere is incontrovertible. Experiments have shown the potential for using Global Positioning System (GPS) receivers to measure total precipitable water vapor ...

Daniel E. Wolfe; Seth I. Gutman

2000-04-01T23:59:59.000Z

335

Analysis of lidar depolarization calibration procedure and application to the atmospheric aerosol characterization  

Science Conference Proceedings (OSTI)

A Raman lidar system is used to monitor the aerosol depolarization features of the urban atmosphere at the Andalusian Centre for Environmental Research CEAMA, in Granada, southeastern Spain. The lidar system was upgraded in 2010 to enable the application ...

Juan Antonio Bravo-Aranda; Francisco Navas-Guzmn; Juan Luis Guerrero-Rascado; Daniel Prez-Ramrez; Mara Jos Granados-Muoz; Lucas Alados-Arboledas

2013-05-01T23:59:59.000Z

336

Two-Column Aerosol Project  

NLE Websites -- All DOE Office Websites (Extended Search)

Climate Research Facility is conducting the Two-Column Aerosol Project (TCAP) at Cape Cod National Seashore. From July 2012 to June 2013, the ARM Mobile Facility-a portable...

337

Mesoscale Variations of Tropospheric Aerosols  

Science Conference Proceedings (OSTI)

Tropospheric aerosols are calculated to cause global-scale changes in the earth's heat balance, but these forcings are space/time integrals over highly variable quantities. Accurate quantification of these forcings will require an unprecedented ...

Theodore L. Anderson; Robert J. Charlson; David M. Winker; John A. Ogren; Kim Holmn

2003-01-01T23:59:59.000Z

338

VARIATIONS OF MERIDIONAL AEROSOL DISTRIBUTION AND SOLAR DIMMING  

SciTech Connect

Meridional distribution of aerosol optical thickness (AOT) over the ocean was analyzed by using the eight-year MISR and MODIS-Terra data sets, from March 2000 to February 2008, as well as the five-year MODIS-Aqua data set, from July 2002 to June 2007. The three independent sensors show that there was a pronounced meridional aerosol asymmetry. It was found that there were strong seasonal variations in the hemispheric aerosol asymmetry: it was pronounced during the half-year period, from March to August (the most pronounced asymmetry was observed from April to July). There was no noticeable asymmetry during the season from September to December. Not only has the Northern hemisphere, where the main sources of aerosols are located, but also the Southern hemisphere contributed to the formation of noticeable aerosol asymmetry. The increase in AOT, averaged over the Northern hemisphere during the season of pronounced hemispheric aerosol asymmetry, was accompanied by a decrease in AOT, averaged over the Southern hemisphere. In both hemispheres, amplitudes of seasonal AOT variations decreases from mid-latitudes (60N - 30N and 30S - 60S) to low latitudes (30N - 0 and 0 - 30S) respectively, indicating that the contribution of AOT averaged over mid-latitudes to the formation of pronounced meridional hemispheric asymmetry and its seasonal variations is more significant than the contribution of AOT averaged over low latitudes. For the season of prominent hemispheric aerosol asymmetry, from April to July, during the eight-year period under consideration, a declining long-term tendency of AOT prevailed at latitudes between 30oN and 60oN, suggesting brightening over the cloud-free ocean.

Kishcha, P.; Starobinets, B.; Kalashnikova, O.; Long, Charles N.; Alpert, P.

2009-06-08T23:59:59.000Z

339

Potential Aerosol Indirect Effects on Atmospheric Circulation and Radiative Forcing through Deep Convection  

Science Conference Proceedings (OSTI)

Aerosol indirect effects, i.e., the interactions of aerosols with clouds by serving as cloud condensation nuclei (CCN) or ice nuclei (IN), constitute the largest uncertainty in climate forcing and projection. Previous IPCC reported aerosol indirect forcing is negative, which does not account for aerosol-convective cloud interactions because 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 to enhanced regional convergence and a strong top-of atmosphere (TOA) warming. Aerosol invigoration effect on convection can result in a strong radiative warming in the atmosphere (+5.6 W m-2) due to strong night-time warming, a lofted latent heating, and a reduced diurnal temperature difference, all of which could remarkably impact regional circulation and modify weather systems. We further elucidated how aerosols change convective intensity, diabatic heating, and regional circulation under different environmental conditions and concluded that wind shear and cloud base temperature play key roles in determining the significance of aerosol invigoration effect for convective systems.

Fan, Jiwen; Rosenfeld, Daniel; Ding, Yanni; Leung, Lai-Yung R.; Li, Zhanqing

2012-05-10T23:59:59.000Z

340

Vertical distribution and radiative effects of mineral dust and biomass burning aerosol over West Africa during DABEX  

SciTech Connect

This paper presents measurements of the vertical distribution of aerosol extinction coefficient over West Africa, during the Dust and Biomass burning aerosol Experiment (DABEX) / African Monsoon Multidisciplinary Analysis dry season Special Observing period zero (AMMA-SOP0). In situ aircraft measurements from the UK FAAM aircraft are compared with two ground based lidars (POLIS and ARM MPL) and an airborne lidar on an ultra-light aircraft. In general mineral dust was observed at low altitudes (up to 2km) and a mixture of biomass burning aerosol and dust was observed at altitudes of 2-5km. The study exposes difficulties associated with spatial and temporal variability when inter-comparing aircraft and ground measurements. Averaging over many profiles provided a better means of assessing consistent errors and biases associated with in situ sampling instruments and retrievals of lidar ratios. Shortwave radiative transfer calculations and a 3-year simulation with the HadGEM2-A climate model show that the radiative effect of biomass burning aerosol is somewhat sensitive to the vertical distribution of aerosol. Results show a 15% increase in absorption of solar radiation by elevated biomass burning aerosol when the observed low-level dust layer is included as part of the background atmospheric state in the model. This illustrates that the radiative forcing of anthropogenic absorbing aerosol is sensitive to the treatment of other aerosol species and that care is needed in simulating natural aerosols assumed to exist in the pre-industrial, or natural state of the atmosphere.

Johnson, Ben; Heese, B.; McFarlane, Sally A.; Chazette, P.; Jones, A.; Bellouin, N.

2008-09-12T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol observing systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Method for producing monodisperse aerosols  

DOE Patents (OSTI)

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.

Ortiz, Lawrence W. (Los Alamos, NM); Soderholm, Sidney C. (Pittsford, NY)

1990-01-01T23:59:59.000Z

342

Aerosol optical depth increase in partly cloudy conditions  

Science Conference Proceedings (OSTI)

Remote sensing observations of aerosol from surface and satellite instruments are extensively used for atmospheric and climate research. From passive sensors, the apparent cloud-free atmosphere in the vicinity of clouds often appears to be brighter then further away from the clouds, leading to an enhancement in the retrieved aerosol optical depth. Mechanisms contributing to this enhancement, including contamination by undetected clouds, hygroscopic growth of aerosol particles, and meteorological conditions, have been debated in recent literature, but an extent to which each of these factors influence the observed enhancement is poorly known. Here we used 11 years of daily global observations at 10x10 km2 resolution from the MODIS on the NASA Terra satellite to quantify as a function of cloud fraction (CF). Our analysis reveals that, averaged over the globe, the clear sky is enhanced by ? = 0.05 which corresponds to relative enhancements of 25% in cloudy conditions (CF=0.8-0.9) compared with relatively clear conditions (CF=0.1-0.2). Unlike the absolute enhancement ?, the relative increase in ? is rather consistent in all seasons and is 25-35% in the subtropics and 15-25% at mid and higher latitudes. Using a simple Gaussian probability density function model to connect cloud cover and the distribution of relative humidity, we argue that much of the enhancement is consistent with aerosol hygroscopic growth in the humid environment surrounding clouds. Consideration of these cloud-dependent effects will facilitate understanding aerosol-cloud interactions and reduce the uncertainty in estimates of aerosol radiative forcing by global climate models.

Chand, Duli; Wood, R.; Ghan, Steven J.; Wang, Minghuai; Ovchinnikov, Mikhail; Rasch, Philip J.; Miller, Steven D.; Schichtel, Bret; Moore, Tom

2012-09-14T23:59:59.000Z

343

Sealing Ducts in Large Commercial Buildings with Aerosolized Sealant  

NLE Websites -- All DOE Office Websites (Extended Search)

Sealing Ducts in Large Commercial Buildings with Aerosolized Sealant Sealing Ducts in Large Commercial Buildings with Aerosolized Sealant Particles Title Sealing Ducts in Large Commercial Buildings with Aerosolized Sealant Particles Publication Type Journal Article LBNL Report Number LBNL-42414 Year of Publication 2001 Authors Modera, Mark P., Olivier Brzozowski, François Rémi Carrié, Darryl J. Dickerhoff, William W. Delp, William J. Fisk, Ronnen M. Levinson, and Duo Wang Journal Energy & Buildings Volume 34 Start Page Chapter Pagination 705-714 Abstract Electricity energy savings potential by eliminating air leakage from ducts in large commercial buildings is on the order of 10 kWh/m2 per year (1 kWh/ft2). We have tested, in two large commercial buildings, a new technology that simultaneously seals duct leaks and measures effective leakage area of ducts. The technology is based upon injecting a fog of aerosolized sealant particles into a pressurized duct system. In brief, this process involves blocking all of the intentional openings in a duct system (e.g., diffusers). Therefore, when the system is pressurized, the only place for the air carrying the aerosol particles to exit the system is through the leaks. The key to the technology is to keep the particles suspended within the airstream until they reach the leaks, and then to have them leave the airstream and deposit on the leak sites. The principal finding from this field study was that the aerosol technology is capable of sealing the leaks in a large commercial building duct system within a reasonable time frame. In the first building, 66% of the leakage area was sealed within 2.5 hours of injection, and in the second building 86% of the leakage area was sealed within 5 hours. We also found that the aerosol could be blown through the VAV boxes in the second building without impacting their calibrations or performance. Some remaining questions are (1) how to achieve sealing rates comparable to those experienced in smaller residential systems; and (2) what tightness level these ducts systems can be brought to by means of aerosol sealing.

344

Radioactive Aerosols as an Index of Air Pollution in the City of Thessaloniki, Greece  

Science Conference Proceedings (OSTI)

This study summarizes results of an investigation done in order to find out how the radioactive aerosols of {sup 7}Be could serve as indicators of air pollution conditions. Beryllium-7 is a cosmic-ray produced radionuclide with an important fraction of its production to take place in the upper troposphere. Once it is formed is rapidly associated with submicron aerosol particles and participates in the formation and growth of the accumulation mode aerosols, which is a major reservoir of pollutants in the atmosphere. In order to define any influence of AMAD of {sup 7}Be aerosols by air pollution conditions, the aerodynamic size distribution of {sup 7}Be aerosols was determined by collecting samples at different locations in the suburban area of the city of Thessaloniki, including rural areas, industrial areas, high elevations, marine environment and the airport area. The aerodynamic size distribution of {sup 7}Be aerosols in different locations was obtained by using Andersen 1-ACFM cascade impactors and the Activity Median Aerodynamic Diameter (AMAD) was determined. Some dependency of the AMADs on height has been observed, while in near marine environment the {sup 7}Be activity size distribution was dominant in the upper size range of aerosol particles. Low AMADs as low as 0.62 to 0.74 {mu}m of {sup 7}Be aerosols have been observed at locations characterized with relative low pollution, while it is concluded that in the activity size distribution of ambient aerosols, {sup 7}Be changes to larger particle sizes in the presence of pollutants, since low AMADs of {sup 7}Be aerosols have been observed at low polluted locations. Preliminary data of simultaneous measurements of {sup 214}Pb and {sup 212}Pb with gaseous air pollutants CO, NO, NO{sub X}, SO{sub 2} and total suspended particulate matter (TSP) show that radon decay products near the ground could be a useful index of air pollution potential conditions and transport processes in the boundary layer.

Ioannidou, A.; Papastefanou, C. [Nuclear Physics and Elementary Particle Physics Division, Physics Department, Aristotle University of Thessaloniki, Thessaloniki 54124 (Greece)

2010-01-21T23:59:59.000Z

345

Signatures of fractal clustering of aerosols advected under gravity  

E-Print Network (OSTI)

Aerosols under chaotic advection often approach a strange attractor. They move chaotically on this fractal set but, in the presence of gravity, they have a net vertical motion downwards. In practical situations, observational data may be available only at a given level, for example at the ground level. We uncover two fractal signatures of chaotic advection of aerosols under the action of gravity. Each one enables the computation of the fractal dimension $D_{0}$ of the strange attractor governing the advection dynamics from data obtained solely at a given level. We illustrate our theoretical findings with a numerical experiment and discuss their possible relevance to meteorology.

Rafael Dias Vilela; Tams Tl; Alessandro P. S. de Moura; Celso Grebogi

2007-06-15T23:59:59.000Z

346

Thermodynamic Characterization of Mexico City Aerosol during MILAGRO 2006  

E-Print Network (OSTI)

Thermodynamic Characterization of Mexico City Aerosol duringA computationally efficient thermodynamic equilibrium modelurban aerosols determined by thermodynamic equilibrium? An

Fountoukis, C.

2009-01-01T23:59:59.000Z

347

The impact of biogenic carbon emissions on aerosol absorption inMexico City  

Science Conference Proceedings (OSTI)

In order to determine the wavelength dependence of atmospheric aerosol absorption in the Mexico City area, the absorption angstrom exponents (AAEs) were calculated from aerosol absorption measurements at seven wavelengths obtained with a seven-channel aethalometer during two field campaigns, the Mexico City Metropolitan Area study in April 2003 (MCMA 2003) and the Megacity Initiative: Local and Global Research Observations in March 2006 (MILAGRO). The AAEs varied from 0.76 to 1.56 in 2003 and from 0.54 to 1.52 in 2006. The AAE values determined in the afternoon were consistently higher than the corresponding morning values, suggesting the photochemical formation of absorbing secondary organic aerosols (SOA) in the afternoon. The AAE values were compared to stable and radiocarbon isotopic measurements of aerosol samples collected at the same time to determine the sources of the aerosol carbon. The fraction of modern carbon (fM) in the aerosol samples, as determined from {sup 14}C analysis, showed that 70% of the carbonaceous aerosols in Mexico City were from modern sources, indicating a significant impact from biomass burning during both field campaigns. The {sup 13}C/{sup 12}C ratios of the aerosol samples illustrate the significant impact of Yucatan forest fires (C-3 plants) in 2003 and local grass fires (C-4 plants) at site T1 in 2006. A direct comparison of the fM values, stable carbon isotope ratios, and calculated aerosol AAEs suggested that the wavelength dependence of the aerosol absorption was controlled by the biogenically derived aerosol components.

Marley, N; Gaffney, J; Tackett, M J; Sturchio, N; Hearty, L; Martinez, N; Hardy, K D; Machany-Rivera, A; Guilderson, T P; MacMillan, A; Steelman, K

2009-02-24T23:59:59.000Z

348

The Arctic Lower Troposphere Observed Structure (ALTOS) Campaign  

SciTech Connect

The ALTOS campaign focuses on operating a tethered observing system for routine in situ sampling of low-level (< 2 km) Arctic clouds. It has been a long-term hope to fly tethered systems at Barrow, Alaska, but it is clear that the Federal Aviation Administration (FAA) will not permit in-cloud tether systems at Barrow, even if unmanned aerial vehicle (UAV) operations are allowed in the future. We have provided the scientific rationale for long-term, routine in situ measurements of cloud and aerosol properties in the Arctic. The existing restricted air space at Oliktok offers an opportunity to do so.

Verlinde, J

2010-10-18T23:59:59.000Z

349

Evaluating WRF-Chem multi-scale model in simulating aerosol radiative properties over the tropics A case study over India  

Science Conference Proceedings (OSTI)

We utilized WRF-Chem multi-scale model to simulate the regional distribution of aerosols, optical properties and its effect on radiation over India for a winter month. The model is evaluated using measurements obtained from upper-air soundings, AERONET sun photometers, various satellite instruments, and pyranometers operated by the Indian Meteorological Department. The simulated downward shortwave flux was overestimated when the effect of aerosols on radiation and clouds was neglected. Downward shortwave radiation from a simulation that included aerosol-radiation interaction processes was 5 to 25 Wm{sup -2} closer to the observations, while a simulation that included aerosol-cloud interaction processes were another 1 to 20 Wm{sup -2} closer to the observations. For the few observations available, the model usually underestimated particulate concentration. This is likely due to turbulent mixing, transport errors and the lack of secondary organic aerosol treatment in the model. The model efficiently captured the broad regional hotspots such as high aerosol optical depth over Indo-Gangetic basin as well as the northwestern and southern part of India. The regional distribution of aerosol optical depth compares well with AVHRR aerosol optical depth and the TOMS aerosol index. The magnitude and wavelength-dependence of simulated aerosol optical depth was also similar to the AERONET observations across India. Differences in surface shortwave radiation between simulations that included and neglected aerosol-radiation interactions were as high as -25 Wm{sup -2}, while differences in surface shortwave radiation between simulations that included and neglect aerosol-radiation-cloud interactions were as high as -30 Wm{sup -2}. The spatial variations of these differences were also compared with AVHRR observation. This study suggests that the model is able to qualitatively simulate the impact of aerosols on radiation over India; however, additional measurements of particulate mass and composition are needed to fully evaluate whether the aerosol precursor emissions are adequate when simulating radiative forcing in the region.

Seethala, C.; Pandithurai, G.; Fast, Jerome D.; Polade, Suraj D.; Reddy, M. S.; Peckham, Steven E.

2012-01-24T23:59:59.000Z

350

ARM - Publications: Science Team Meeting Documents: Effects of Aerosol Size  

NLE Websites -- All DOE Office Websites (Extended Search)

Effects of Aerosol Size Distribution and Vertical Profile on the Effects of Aerosol Size Distribution and Vertical Profile on the Polarization in the Oxygen A-Band Duan, Minzheng State University of New York at Albany Min, Qilong State University of New York at Albany A vector radiative transfer code with successive order of scattering method was used to simulate the high-resolution polarization spectra in the oxygen A-band. The effects of aerosol size distribution and vertical profile on the radiance and polarization at the top and bottom of the atmosphere were analyzed. The impacts of instrument specification on information content are also analyzed. Polarized radiances were dominated (>95%) by the first and second orders of scattering. The contributions of scattering from different levels to the TOA and surface observation are analyzed. The

351

Direct Aerosol Forcing in the Infrared at the SGP Site?  

NLE Websites -- All DOE Office Websites (Extended Search)

Direct Aerosol Forcing in the Infrared at the SGP Site? Direct Aerosol Forcing in the Infrared at the SGP Site? D. D. Turner and C. N. Long Pacific Northwest National Laboratory Richland, Washington Introduction Low level haze is often observed during the night and early morning hours in many locations. This haze is typically formed during quiescent conditions by radiative cooling of the surface, which lowers the ambient temperature and consequently increases the near-surface relative humidity (RH). Many aerosols start to deliquesce around 75% relative humidity (RH) (depending on their chemical composition), and thus if the near surface RH increases above this level, haze will form. The Atmospheric Radiation Measurement (ARM) Program's ultimate goal, stated simply, is to improve the treatment of radiative transfer in global climate models. Global climate models typically do not

352

UV Sensitivity to Changes in Ozone, Aerosols and Clouds in Seoul, Korea  

Science Conference Proceedings (OSTI)

The total ozone (O3) and aerosol optical depth (AOD) at 320 nm have been observed from the ultraviolet (UV) measurements made at Yonsei University in Seoul, Korea with Dobson and Brewer spectrophotometers, respectively, during 2004-2010. The daily ...

Woogyung Kim; Jhoon Kim; Sang Seo Park; Hi-Ku Cho

353

Saharan Aerosols over the South of France: Characterization Derived from Satellite Data and Ground Based Measurements  

Science Conference Proceedings (OSTI)

In July 1983, the summer transport of Saharian aerosols across the Mediterranean Sea was observed. The dust cloud was particularly dense and was clearly detected in A.V.H.R.R. and METEOSAT imageries. Optical thickness and Angstrm coeffcients ...

J. L. Deuze; C. Devaux; M. Herman; R. Santer; D. Tanre

1988-05-01T23:59:59.000Z

354

Polarization Lidar and Synoptic Analyses of an Unusual Volcanic Aerosol Cloud  

Science Conference Proceedings (OSTI)

Over an unusually brief three-day period in early August 1989, spectacular twilight effects indicative of a stratospheric volcanic cloud were seen at Salt Lake City, Utah. Concurrent polarization lidar observations detected an aerosol layer at ...

Kenneth Sassen; John D. Horel

1990-12-01T23:59:59.000Z

355

An A-Train Strategy for Quantifying Direct Climate Forcing by Anthropogenic Aerosols  

Science Conference Proceedings (OSTI)

This document outlines a practical strategy for achieving an observationally based quantification of direct climate forcing by anthropogenic aerosols. The strategy involves a four-step program for shifting the current assumption-laden estimates ...

Theodore L. Anderson; Robert J. Charlson; Nicolas Bellouin; Olivier Boucher; Mian Chin; Sundar A. Christopher; Jim Haywood; Yoram J. Kaufman; Stefan Kinne; John A. Ogren; Lorraine A. Remer; Toshihiko Takemura; Didier Tanr; Omar Torres; Charles R. Trepte; Bruce A. Wielicki; David M. Winker; Hongbin Yu

2005-12-01T23:59:59.000Z

356

The Impact of Aerosols on the Summer Rainfall Frequency in China  

Science Conference Proceedings (OSTI)

The authors investigate the short-term relationship between aerosol concentrations and summer rainfall frequency in China using the daily surface observations of particulate matters with a diameter of less than 10 ?m (PM10) mass concentration, ...

Yong-Sang Choi; Chang-Hoi Ho; Jinwon Kim; Dao-Yi Gong; Rokjin J. Park

2008-06-01T23:59:59.000Z

357

Climatic effects of 19502050 changes in US anthropogenic aerosols Part 2: Climate response  

E-Print Network (OSTI)

We investigate the climate response to changing US anthropogenic aerosol sources over the 19502050 period by using the NASA GISS general circulation model (GCM) and comparing to observed US temperature trends. Time-dependent ...

Leibensperger, Eric Michael

358

Aerosol-Induced Large-Scale Variability in Precipitation over the Tropical Atlantic  

Science Conference Proceedings (OSTI)

Multiyear satellite observations are used to document a relationship between the large-scale variability in precipitation over the tropical Atlantic and aerosol traced to African sources. During boreal winter and spring there is a significant ...

Jingfeng Huang; Chidong Zhang; Joseph M. Prospero

2009-10-01T23:59:59.000Z

359

Factors Determining the Impact of Aerosols on Surface Precipitation from Clouds: An Attempt at Classification  

Science Conference Proceedings (OSTI)

The simulation of the dynamics and the microphysics of clouds observed during the Large-Scale BiosphereAtmosphere Experiment in AmazoniaSmoke, Aerosols, Clouds, Rainfall, and Climate (LBASMOCC) campaign, as well as extremely continental and ...

A. P. Khain; N. BenMoshe; A. Pokrovsky

2008-06-01T23:59:59.000Z

360

A Model of the Radiative Properties of the EL Chichon Stratospheric Aerosol Layer  

Science Conference Proceedings (OSTI)

An accurate multiple-scattering model has been employed to examine the effect of an aerosol layer at 25 mb, corresponding to the EL Chichon observations, on the reflection, transmission and absorption of radiation by the stratosphere as a ...

Michael D. King; Harshvardhan; Albert Arking

1984-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol observing systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

The dependence of cloud particle size and precipitation probability on non-aerosol-loading related variables  

NLE Websites -- All DOE Office Websites (Extended Search)

Explaining and reducing the uncertainties in the first aerosol i Explaining and reducing the uncertainties in the first aerosol i Explaining and reducing the uncertainties in the first aerosol indirect effect ndirect effect Hongfei Shao and Guosheng Liu Meteorology Department, Florida State University INTRODUCTION INTRODUCTION Anthropogenic aerosols enhance cloud reflectance of solar radiation by increasing the cloud droplet number concentrations. This so-called first Aerosol Indirect Effect (AIE) has a potentially large cooling tendency on our planet. However, discrepancies of more than a factor of 2 have been reported among observations 1 as well as model simulations 2 of the AIE. Our recent study 3 shows that the discrepancies will be reduced greatly if the entrainment-mixing evaporation of cloud drops is taken into account.

362

The Radiative Effects of Aerosols on Photochemical Smog: Measurements and Modeling  

E-Print Network (OSTI)

. High concentrations of both ozone and aerosols are observed in the eastern United States during stagnant weather conditions associated with transport from the W or NW; they show similar spatial and temporal patterns. We discuss a causal mechanism that may contribute to this correlation - the radiative effects of aerosols on photolysis rates. We measured j(NO 2 ), the rate coefficient for nitrogen dioxide photolysis, and column aerosol optical depths at NASA/Goddard Space Flight Center in Greenbelt, MD (39.01 ffi N and 76.87 ffi W) during the smog seasons of 1995 and 1997. Direct measurements and radiative transfer model calculations show that particles can reduce surface j(NO 2 ) by 5 - 60%, depending on solar zenith angle and aerosol loading. Although particle scattering by dense aerosol loading on smoggy days decreases near-surface photolysis rates, it increases the integrated boundary layer photolysis rates by up to 20% and leads to accelerated photochemical smog formation in ...

Kondragunta Dickerson Stenchikov; S. Kondragunta; R. R. Dickerson; G. Stenchikov; W. F. Ryan; B. Holben; R. W. Stewart

2000-01-01T23:59:59.000Z

363

Direct and semi-direct aerosol effects of Southern African1 biomass burning aerosol2  

E-Print Network (OSTI)

1 Direct and semi-direct aerosol effects of Southern African1 biomass burning aerosol2 Naoko effects of biomass burning aerosols from Southern African fires9 during July-October are investigated region the overall TOA radiative effect from the23 biomass burning aerosols is almost zero due

Wood, Robert

364

Modeling the Direct and Indirect Effects of Atmospheric Aerosols on Tropical Cyclones  

E-Print Network (OSTI)

The direct and indirect effects of aerosols on the hurricane Katrina have been investigated using the WRF model with a two-moment bulk microphysical scheme and modified Goddard shortwave radiation scheme. Simulations of the hurricane Katrina are conducted under the three aerosol scenarios: 1) the clean case with an aerosol number concentration of 200 cm-1, 2) the polluted case with a number concentration of 1000 cm-1, and 3) the aerosol radiative effects (AR) case with same aerosol concentration as polluted case but with a modified shortwave radiation scheme. The polluted and AR cases have much larger amounts of cloud water and water vapor in troposphere, and the increased cloud water can freeze to produce ice water paths. A tropical cyclone in dirty and dusty air has active rainbands outside the eyewall due to aerosol indirect effects. The aerosol direct effect can lead to the suppressing of convection and weakening of updraft intensity by warming the troposphere and cooling the surface temperature. However, these thermal changes in atmosphere are concerned with the enhanced amounts of cloud hydrometeors and modification of downdraft and corresponding the low level winds in rainband regions. Thus, the AR case can produce the enhanced precipitation even in the weakest hurricane. When comparing the model performance between aerosol indirect and direct effect by ensemble experiments, the adjustment time of the circulation due to modification of the aerosol radiative forcing by aerosol layers may take a longer time than the hurricane lifetime, and the results from the simulated hurricane show that it is more sensitive to aerosol indirect effects which are related to the cloud microphysics process changes. From this aerosol study, we can suggest that aerosols can influence the cloudiness, precipitation, and intensity of hurricanes significantly, and there may be different results in the meso-scale convective clouds cases. The hurricane system is a large and complex convective system with enormous heating energy and moistures. Moreover, relationships between various hydrometeors in hurricane systems are difficult to isolate and thus, it needs further study with more realistic cloud microphysical processes, aerosol distributions, and parameterizations.

Lee, Keun-Hee

2011-12-01T23:59:59.000Z

365

ARM - Field Campaign - Fall 1997 Aerosol IOP  

NLE Websites -- All DOE Office Websites (Extended Search)

Aerosol IOP Aerosol IOP Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Fall 1997 Aerosol IOP 1997.09.15 - 1997.10.05 Lead Scientist : Stephen Schwartz For data sets, see below. Summary The Aerosol IOP was highlighted by the Gulfstream-1 aircraft flying clear-sky aerosol missions over the Central Facility to study the effect of aerosol loading on clear sky radiation fields, with weather particularly favorable for these flights during the first and third weeks of the IOP. A secondary but important goal of this IOP was to fly cloudy-sky missions over the Central Facility to study the effect of aerosol loading on cloud microphysics, and the effect of the microphysics on cloud optical properties. The Gulfstream obtained aerosol data in support of some of the

366

ARM - Evaluation Product - Organic Aerosol Component VAP  

NLE Websites -- All DOE Office Websites (Extended Search)

ProductsOrganic Aerosol Component VAP ProductsOrganic Aerosol Component VAP Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Evaluation Product : Organic Aerosol Component VAP 2011.01.08 - 2012.03.24 Site(s) SGP General Description Organic aerosol (OA, i.e., the organic fraction of particles) accounts for 10-90% of the fine aerosol mass globally and is a key determinant of aerosol radiative forcing. But atmospheric OA is poorly characterized and its life cycle insufficiently represented in models. As a result, current models are unable to simulate OA concentrations and properties. This deficiency represents a large source of uncertainty in the quantification of aerosol direct and indirect effects and the prediction of future climate change. The Organic Aerosol Component (OACOMP) value-added product (VAP) uses

367

Climate Response to Soil Dust Aerosols  

Science Conference Proceedings (OSTI)

The effect of radiative forcing by soil dust aerosols upon climate is calculated. Two atmospheric GCM (AGCM) simulations are compared, one containing a prescribed seasonally varying concentration of dust aerosols, and the other omitting dust. ...

R. L. Miller; I. Tegen

1998-12-01T23:59:59.000Z

368

Indirect and Semi-direct Aerosol Campaign  

Science Conference Proceedings (OSTI)

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 ...

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

2011-02-01T23:59:59.000Z

369

MELCOR 1.8.2 assessment: Aerosol experiments ABCOVE AB5, AB6, AB7, and LACE LA2  

SciTech Connect

The MELCOR computer code has been used to model four of the large-scale aerosol behavior experiments conducted in the Containment System Test Facility (CSTF) vessel. Tests AB5, AB6 and AB7 of the ABCOVE program simulate the dry aerosol conditions during a hypothetical severe accident in an LMFBR. Test LA2 of the LACE program simulates aerosol behavior in a condensing steam environment during a postulated severe accident in an LWR with failure to isolate the containment. The comparison of code results to experimental data show that MELCOR is able to correctly predict most of the thermal-hydraulic results in the four tests. MELCOR predicts reasonably well the dry aerosol behavior of the ABCOVE tests, but significant disagreements are found in the aerosol behavior modelling for the LA2 experiment. These results tend to support some of the concerns about the MELCOR modelling of steam condensation onto aerosols expressed in previous works. During these analyses, a limitation in the MELCOR input was detected for the specification of the aerosol parameters for more than one component. A Latin Hypercube Sampling (LHS) sensitivity study of the aerosol dynamic constants is presented for test AB6. The study shows the importance of the aerosol shape factors in the aerosol deposition behavior, and reveals that MELCOR input/output processing is highly labor intensive for uncertainty and sensitivity analyses based on LHS.

Souto, F.J.; Haskin, F.E. [Univ. of New Mexico, Albuquerque, NM (United States). Dept. of Chemical and Nuclear Engineering; Kmetyk, L.N. [Sandia National Labs., Albuquerque, NM (United States)

1994-10-01T23:59:59.000Z

370

Single particle characterization, source apportionment, and aging effects of ambient aerosols in Southern California  

E-Print Network (OSTI)

detection efficiencies of aerosol time of flight masscomposition of ambient aerosol particles. Environmentalsize dependent response of aerosol counters, Atmospheric

Shields, Laura Grace

2008-01-01T23:59:59.000Z

371

Aerosol Optical Depth over Oceans: High Space- and Time-Resolution Retrieval and Error Budget from Satellite Radiometry  

Science Conference Proceedings (OSTI)

A method to retrieve aerosol vertical optical depth at 0.64 ?m from satellite observations of cloud-free scenes over oceans with high spatial resolution (1) and instantaneous temporal resolution is described and evaluated. The observed radiance ...

Richard Wagener; Seth Nemesure; Stephen E. Schwartz

1997-06-01T23:59:59.000Z

372

Results and code prediction comparisons of lithium-air reaction and aerosol behavior tests  

Science Conference Proceedings (OSTI)

The Hanford Engineering Development Laboratory (HEDL) Fusion Safety Support Studies include evaluation of potential safety and environmental concerns associated with the use of liquid lithium as a breeder and coolant for fusion reactors. Potential mechanisms for volatilization and transport of radioactive metallic species associated with breeder materials are of particular interest. Liquid lithium pool-air reaction and aerosol behavior tests were conducted with lithium masses up to 100 kg within the 850-m/sup 3/ containment vessel in the Containment Systems Test Facility. Lithium-air reaction rates, aerosol generation rates, aerosol behavior and characterization, as well as containment atmosphere temperature and pressure responses were determined. Pool-air reaction and aerosol behavior test results were compared with computer code calculations for reaction rates, containment atmosphere response, and aerosol behavior. The volatility of potentially radioactive metallic species from a lithium pool-air reaction was measured. The response of various aerosol detectors to the aerosol generated was determined. Liquid lithium spray tests in air and in nitrogen atmospheres were conducted with lithium temperatures of about 427/sup 0/ and 650/sup 0/C. Lithium reaction rates, containment atmosphere response, and aerosol generation and characterization were determined for these spray tests.

Jeppson, D.W.

1986-03-01T23:59:59.000Z

373

Mechanisms Linking Volcanic Aerosols to the Atlantic Meridional Overturning Circulation  

Science Conference Proceedings (OSTI)

This study examines the sensitivity of the climate system to volcanic aerosol forcing in the third climate configuration of the Met Office Unified Model (HadCM3). The main test case was based on the 1880s when there were several volcanic eruptions,...

Alan M. Iwi; Leon Hermanson; Keith Haines; Rowan T. Sutton

2012-04-01T23:59:59.000Z

374

Influence of aerosols from biomass burning on the spectral analysis of Cherenkov telescopes  

E-Print Network (OSTI)

During the last decade, imaging atmospheric Cherenkov telescopes (IACTs) have proven themselves as astronomical detectors in the very-high-energy (VHE; E>0.1 TeV) regime. The IACT technique observes the VHE photons indirectly, using the Earth's atmosphere as a calorimeter. Much of the calibration of Cherenkov telescope experiments is done using Monte Carlo simulations of the air shower development, Cherenkov radiation and detector, assuming certain models for the atmospheric conditions. Any deviation of the real conditions during observations from the assumed atmospheric model will result in a wrong reconstruction of the primary gamma-ray energy and the resulting source spectra. During eight years of observations, the High Energy Stereoscopic System (H.E.S.S.) has experienced periodic natural as well as anthropogenic variations of the atmospheric transparency due to aerosols created by biomass burning. In order to identify data that have been taken under such long-term reductions in atmospheric transparency, ...

Reyes, R de los; Bernloehr, K; Krueger, P; Deil, C; Gast, H; Kosack, K; Marandon, V

2013-01-01T23:59:59.000Z

375

Scanning Transmission X-ray Microscopy: Applications in Atmospheric Aerosol Research  

E-Print Network (OSTI)

in secondary organic aerosol. Environ. Sci. Technol. 41 ,particles from an urban aerosol. Environ. Sci. Technol. 26 ,carbonaceous atmospheric aerosols. Journal of Aerosol

Moffet, Ryan C.

2011-01-01T23:59:59.000Z

376

ARM - Measurement - Aerosol optical properties  

NLE Websites -- All DOE Office Websites (Extended Search)

properties properties 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 : Aerosol optical properties The optical properties of aerosols, including asymmetry factor, phase-function, single-scattering albedo, refractive index, and backscatter fraction. Categories Aerosols Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments CSPHOT : Cimel Sunphotometer NEPHELOMETER : Nephelometer Field Campaign Instruments AOS-PMFOV : Acoustical Optical Spectrometer-Photometer with Multiple

377

ARM - Measurement - Aerosol optical depth  

NLE Websites -- All DOE Office Websites (Extended Search)

depth depth 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 : Aerosol optical depth A measure of how much light aerosols prevent from passing through a column of atmosphere. Categories Aerosols Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments HSRL : High Spectral Resolution Lidar MPL : Micropulse Lidar MFRSR : Multifilter Rotating Shadowband Radiometer NIMFR : Normal Incidence Multifilter Radiometer Field Campaign Instruments AOS-PMFOV : Acoustical Optical Spectrometer-Photometer with Multiple

378

Effect of Terrestrial and Marine Organic Aerosol on Regional and Global Climate: Model Development, Application, and Verification with Satellite Data  

SciTech Connect

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???????°????????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 physics options in GWRF for global scale modeling in 2001 at a horizontal grid resolution of 1???????° x 1???????°. GU-WRF model output was evaluated using observational datasets from a variety of sources including surface based observations (NCDC and BSRN), model reanalysis (NCEP/ NCAR Reanalysis and CMAP), and remotely-sensed data (TRMM) to evaluate the ability of GU-WRF to simulate atmospheric variables at the surface as well as aloft. Explicit treatment of nanoparticles produced from new particle formation in GU-WRF/Chem-MADRID was achieved by expanding particle size sections from 8 to 12 to cover particles with the size range of 1.16 nm to 11.6 ???????µm. Simulations with two different nucleation parameterizations were conducted for August 2002 over a global domain at a 4???????º by 5???????º horizontal resolution. The results are evaluated against field measurement data from the 2002 Aerosol Nucleation and Real Time Characterization Experiment (ANARChE) in Atlanta, Georgia, as well as satellite and reanalysis data. We have also explored the relationship between ???¢????????clean marine???¢??????? aerosol optical properties and ocean surface wind speed using remotely sensed data from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) on board the CALIPSO satellite and the Advanced Microwave Scanning Radiometer (AMSR-E) on board the AQUA satellite. Detailed data analyses

Meskhidze, Nicholas; Zhang, Yang; Kamykowski, Daniel

2012-03-28T23:59:59.000Z

379

Effect of Terrestrial and Marine Organic Aerosol on Regional and Global Climate: Model Development, Application, and Verification with Satellite Data  

Science Conference Proceedings (OSTI)

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???????°????????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 physics options in GWRF for global scale modeling in 2001 at a horizontal grid resolution of 1???????° x 1???????°. GU-WRF model output was evaluated using observational datasets from a variety of sources including surface based observations (NCDC and BSRN), model reanalysis (NCEP/ NCAR Reanalysis and CMAP), and remotely-sensed data (TRMM) to evaluate the ability of GU-WRF to simulate atmospheric variables at the surface as well as aloft. Explicit treatment of nanoparticles produced from new particle formation in GU-WRF/Chem-MADRID was achieved by expanding particle size sections from 8 to 12 to cover particles with the size range of 1.16 nm to 11.6 ???????µm. Simulations with two different nucleation parameterizations were conducted for August 2002 over a global domain at a 4???????º by 5???????º horizontal resolution. The results are evaluated against field measurement data from the 2002 Aerosol Nucleation and Real Time Characterization Experiment (ANARChE) in Atlanta, Georgia, as well as satellite and reanalysis data. We have also explored the relationship between ???¢????????clean marine???¢??????? aerosol optical properties and ocean surface wind speed using remotely sensed data from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) on board the CALIPSO satellite and the Advanced Microwave Scanning Radiometer (AMSR-E) on board the AQUA satellite. Detailed data analyses

Meskhidze, Nicholas; Zhang, Yang; Kamykowski, Daniel

2012-03-28T23:59:59.000Z

380

The Effect of Atmospheric Water Vapor on Neutron Count in the Cosmic-Ray Soil Moisture Observing System  

Science Conference Proceedings (OSTI)

The cosmic-ray method for measuring soil moisture, used in the COsmic-ray Soil Moisture Observing System (COSMOS), relies on the exceptional ability of hydrogen to moderate fast neutrons. Sources of hydrogen near the ground, other than soil ...

R. Rosolem; W. J. Shuttleworth; M. Zreda; T. E. Franz; X. Zeng; S. A. Kurc

Note: This page contains sample records for the topic "aerosol observing systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Comparing the Convective Structure and Microphysics in Two Sahelian Mesoscale Convective Systems: Radar Observations and CRM Simulations  

Science Conference Proceedings (OSTI)

Two mesoscale convective systems (MCSs) observed during the African Monsoon Multidisciplinary Analyses (AMMA) experiment are simulated using the three-dimensional (3D) Goddard Cumulus Ensemble model. This study was undertaken to determine the ...

Nick Guy; Xiping Zeng; Steven A. Rutledge; Wei-Kuo Tao

2013-02-01T23:59:59.000Z

382

Performance Evaluation for a Lightning Location System Based on Observations of Artificially Triggered Lightning and Natural Lightning Flashes  

Science Conference Proceedings (OSTI)

Performance evaluation for the lightning location system (LLS) of the power grid in Guangdong Province, China, was conducted based on observation data of the triggered lightning flashes obtained in Conghua, Guangzhou, during 200711 and natural ...

Luwen Chen; Yijun Zhang; Weitao Lu; Dong Zheng; Yang Zhang; Shaodong Chen; Zhihui Huang

2012-12-01T23:59:59.000Z

383

The Effect of Atmospheric Water Vapor on Neutron Count in the Cosmic-Ray Soil Moisture Observing System  

Science Conference Proceedings (OSTI)

The cosmic-ray method for measuring soil moisture, used in the Cosmic-Ray Soil Moisture Observing System (COSMOS), relies on the exceptional ability of hydrogen to moderate fast neutrons. Sources of hydrogen near the ground, other than soil ...

R. Rosolem; W. J. Shuttleworth; M. Zreda; T. E. Franz; X. Zeng; S. A. Kurc

2013-10-01T23:59:59.000Z

384

Electrification of Stratiform Regions in Mesoscale Convective Systems. Part I: An Observational Comparison of Symmetric and Asymmetric MCSs  

Science Conference Proceedings (OSTI)

The kinematic, microphysical, and electrical structures of two mesoscale convective systems (MCSs) observed during the 1991 Cooperative Oklahoma Profiler Studies (COPS91) experiment are analyzed. Profiles of the vertical electric field structure ...

Terry J. Schuur; Steven A. Rutledge

2000-07-01T23:59:59.000Z

385

Accuracy of Diagnostic Heat and Moisture Budgets Using SESAME-79 Field Data as Revealed by Observing System Simulation Experiments  

Science Conference Proceedings (OSTI)

The accuracy of diagnostic heat and moisture budgets using the AVE-SESAME 1979 data is investigated through a series of observing system simulation experiments. The four-dimensional (including time) data set provided by a mesoscale model is used ...

Ying-Hwa Kuo; Richard A. Anthes

1984-08-01T23:59:59.000Z

386

SMA Observations of Class 0 Protostars: A High-Angular Resolution Survey of Protostellar Binary Systems  

E-Print Network (OSTI)

We present high angular resolution 1.3 mm and 850 um dust continuum data obtained with the Submillimeter Array toward 33 Class 0 protostars in nearby clouds (distance < 500 pc), which represents so far the largest survey toward protostellar binary/multiple systems. The median angular resolution in the survey is 2.5 arcsec, while the median linear resolution is approximately 600 AU. Compact dust continuum emission is observed from all sources in the sample. Twenty-one sources in the sample show signatures of binarity/multiplicity, with separations ranging from 50 to 5000 AU. The numbers of singles, binaries, triples, and quadruples in the sample are 12, 14, 5, and 2, respectively. The derived multiplicity frequency (MF) and companion star fraction (CSF) for Class 0 protostars are 0.64+/-0.08 and 0.91+/-0.05, respectively, with no correction for completeness. The derived MF and CSF in this survey are approximately two times higher than the values found in the binary surveys toward Class I YSOs, and approxima...

Chen, Xuepeng; Zhang, Qizhou; Bourke, Tyler L; Launhardt, Ralf; Jorgensen, Jes K; Lee, Chin-Fee; Foster, Jonathan B; Dunham, Michael M; Pineda, Jaime E; Henning, Thomas

2013-01-01T23:59:59.000Z

387

Stratospheric Ion and Aerosol Chemistry and Possible Links with Cirrus Cloud MicrophysicsA Critical Assessment  

Science Conference Proceedings (OSTI)

It has been postulated that variations in galactic cosmic rays could affect production of stratospheric aerosols which, after transport to the upper troposphere, could affect latent heat release in convective and cyclonic systems. This hypothesis ...

Volker A. Mohnen

1990-08-01T23:59:59.000Z

388

Development of Dual-Air-Assistant Atomizing Nozzle to Apply Aerosol...  

NLE Websites -- All DOE Office Websites (Extended Search)

Development of Dual-Air-Assistant Atomizing Nozzle to Apply Aerosol-Sealing Technology in Air Duct Systems Speaker(s): Alan Ropers Date: July 8, 2002 - 12:00pm Location: Bldg. 90...

389

Nonlinear Aspects of the Climate Response to Greenhouse Gas and Aerosol Forcing  

Science Conference Proceedings (OSTI)

In a series of equilibrium experiments the climate response to present-day radiative forcings of anthropogenic greenhouse gases and aerosol particles is calculated. The study was performed with a model system consisting of the ECHAM4 atmospheric ...

Johann Feichter; Erich Roeckner; Ulrike Lohmann; Beate Liepert

2004-06-01T23:59:59.000Z

390

Response of Tropical Deep Convection to Localized Heating Perturbations: Implications for Aerosol-Induced Convective Invigoration  

Science Conference Proceedings (OSTI)

A cloud-system-resolving model is used to investigate the effects of localized heating/cooling perturbations on tropical deep convection, in the context of the aerosol invigoration effect. This effect supposes that a reduction of droplet ...

Hugh Morrison; Wojciech W. Grabowski

2013-11-01T23:59:59.000Z

391

Portable Raman Lidar PollyXT for Automated Profiling of Aerosol Backscatter, Extinction, and Depolarization  

Science Conference Proceedings (OSTI)

Two versions of the portable aerosol Raman lidar system (Polly) are presented. First, the two-channel prototype is depicted. It has been developed for the independent and simultaneous determination of particle backscatter and extinction ...

Dietrich Althausen; Ronny Engelmann; Holger Baars; Birgit Heese; Albert Ansmann; Detlef Mller; Mika Komppula

2009-11-01T23:59:59.000Z

392

Comparing Aerosol and Low-Level Moisture Influences on Supercell Tornadogenesis: Three-Dimensional Idealized Simulations  

Science Conference Proceedings (OSTI)

Four three-dimensional, nested-grid numerical simulations were performed using the Regional Atmospheric Modeling System (RAMS) to compare the effects of aerosols acting as cloud condensation nuclei (CCN) to those of low-level moisture [and thus ...

David G. Lerach; William R. Cotton

2012-03-01T23:59:59.000Z

393

Direct Insertion of MODIS Radiances in a Global Aerosol Transport Model  

Science Conference Proceedings (OSTI)

In this paper results are presented from a simple offline assimilation system that uses radiances from the Moderate Resolution Imaging Spectroradiometer (MODIS) channels that sense atmospheric aerosols over land and ocean. The MODIS information ...

Clark Weaver; Arlindo da Silva; Mian Chin; Paul Ginoux; Oleg Dubovik; Dave Flittner; Aahmad Zia; Lorraine Remer; Brent Holben; Watson Gregg

2007-03-01T23:59:59.000Z

394

Differentiating between Clouds and Heavy Aerosols in Sun-Glint Regions  

Science Conference Proceedings (OSTI)

An approach is presented to distinguish between clouds and heavy aerosols in sun-glint regions with automated cloud classification algorithms developed for the National Polar-orbiting Operational Environmental Satellite System (NPOESS) program. ...

Keith D. Hutchison; Bruce Hauss; Barbara D. Iisager; Hiroshi Agravante; Robert Mahoney; Alain Sei; John M. Jackson

2010-06-01T23:59:59.000Z

395

Distinguishing Aerosols from Clouds in Global, Multispectral Satellite Data with Automated Cloud Classification Algorithms  

Science Conference Proceedings (OSTI)

A new approach is presented to distinguish between clouds and heavy aerosols with automated cloud classification algorithms developed for the National Polar-orbiting Operational Environmental Satellite System (NPOESS) program. These new ...

Keith D. Hutchison; Barbara D. Iisager; Thomas J. Kopp; John M. Jackson

2008-04-01T23:59:59.000Z

396

FY 2011 Third Quarter Report Estimate of Historical Aerosol Direct and Indirect Effects  

Science Conference Proceedings (OSTI)

The global and annual mean aerosol direct and indirect effects estimated from Community Earth System Model (CESM) simulations are -0.06 W m-2 and -1.39 W m-2, respectively.

Koch, D

2011-06-22T23:59:59.000Z

397

Real time infrared aerosol analyzer  

DOE Patents (OSTI)

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.

Johnson, Stanley A. (Countryside, IL); Reedy, Gerald T. (Bourbonnais, IL); Kumar, Romesh (Naperville, IL)

1990-01-01T23:59:59.000Z

398

Chemical Source Inversion Using Assimilated Constituent Observations in an Idealized Two-Dimensional System  

Science Conference Proceedings (OSTI)

A source inversion technique for chemical constituents is presented that uses assimilated constituent observations rather than directly using the observations. The method is tested with a simple model problem, which is a two-dimensional Fourier...

Andrew Tangborn; Robert Cooper; Steven Pawson; Zhibin Sun

2009-09-01T23:59:59.000Z

399

A Prototype WRF-Based Ensemble Data Assimilation System for Dynamically Downscaling Satellite Precipitation Observations  

Science Conference Proceedings (OSTI)

In the near future, the Global Precipitation Measurement (GPM) mission will provide precipitation observations with unprecedented accuracy and spatial/temporal coverage of the globe. For hydrological applications, the satellite observations need ...

Dusanka Zupanski; Sara Q. Zhang; Milija Zupanski; Arthur Y. Hou; Samson H. Cheung

2011-02-01T23:59:59.000Z

400

LESSONS LEARNED IN AEROSOL MONITORING WITH THE RASA  

SciTech Connect

The Radionuclide Aerosol Sampler/Analyzer (RASA) is an automated aerosol collection and analysis system designed by Pacific Northwest National Laboratory (PNNL) in the 1990's and is deployed in several locations around the world as part of the International Monitoring System (IMS) required under the Comprehensive Nuclear-Test-Ban Treaty (CTBT). The RASA operates unattended, save for regularly scheduled maintenance, iterating samples through a three-step process on a 24-hour interval. In its 15-year history, much has been learned from the operation and maintenance of the RASA that can benefit engineering updates or future aerosol systems. On 11 March 2011, a 9.0 magnitude earthquake and tsunami rocked the eastern coast of Japan, resulting in power loss and cooling failures at the Daiichi nuclear power plants in Fukushima Prefecture. Aerosol collections were conducted with the RASA in Richland, WA. We present a summary of the lessons learned over the history of the RASA, including lessons taken from the Fukushima incident, regarding the RASA IMS stations operated by the United States.

Forrester, Joel B.; Bowyer, Ted W.; Carty, Fitz; Comes, Laura; Eslinger, Paul W.; Greenwood, Lawrence R.; Haas, Derek A.; Hayes, James C.; Kirkham, Randy R.; Lepel, Elwood A.; Litke, Kevin E.; Miley, Harry S.; Morris, Scott J.; Schrom, Brian T.; Van Davelaar, Peter; Woods, Vincent T.

2011-09-14T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol observing systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Vapor scavenging by atmospheric aerosol particles  

Science Conference Proceedings (OSTI)

Particle growth due to vapor scavenging was studied using both experimental and computational techniques. Vapor scavenging by particles is an important physical process in the atmosphere because it can result in changes to particle properties (e.g., size, shape, composition, and activity) and, thus, influence atmospheric phenomena in which particles play a role, such as cloud formation and long range transport. The influence of organic vapor on the evolution of a particle mass size distribution was investigated using a modified version of MAEROS (a multicomponent aerosol dynamics code). The modeling study attempted to identify the sources of organic aerosol observed by Novakov and Penner (1993) in a field study in Puerto Rico. Experimentally, vapor scavenging and particle growth were investigated using two techniques. The influence of the presence of organic vapor on the particle`s hydroscopicity was investigated using an electrodynamic balance. The charge on a particle was investigated theoretically and experimentally. A prototype apparatus--the refractive index thermal diffusion chamber (RITDC)--was developed to study multiple particles in the same environment at the same time.

Andrews, E.

1996-05-01T23:59:59.000Z

402

An Observation System Used To Study the Marine Boundary Layer Over the Bay of Bengal During Summer Monex 79  

Science Conference Proceedings (OSTI)

An observation system used to study the marine boundary layer over the Bay of Bengal at Digha Beach, West Bengal, India, as part of the International Monsoon Experiments (MONEX 79) is described in this paper. It was a portable system that was ...

S. SethuRaman; P. Michael; W. A. Tuthill; J. McNeil

1980-10-01T23:59:59.000Z

403

Temporal Variability of Aerosol Properties during TCAP: Impact on Radiative Forcing  

SciTech Connect

Ground-based remote sensing and in situ observations of aerosol microphysical and optical properties have been collected during summertime (June-August, 2012) as part of the Two-Column Aerosol Project (TCAP; http://campaign.arm.gov/tcap/), which was supported by the U.S. Department of Energys (DOEs) Atmospheric Radiation Measurement (ARM) Program (http://www.arm.gov/). The overall goal of the TCAP field campaign is to study the evolution of optical and microphysical properties of atmospheric aerosol transported from North America to the Atlantic and their impact on the radiation energy budget. During TCAP, the ground-based ARM Mobile Facility (AMF) was deployed on Cape Cod, an arm-shaped peninsula situated on the easternmost portion of Massachusetts (along the east coast of the United States) and that is generally downwind of large metropolitan areas. The AMF site was equipped with numerous instruments for sampling aerosol, cloud and radiative properties, including a Multi-Filter Rotating Shadowband Radiometer (MFRSR), a Scanning Mobility Particle Sizer (SMPS), an Aerodynamic Particle Sizer (APS), and a three-wavelength nephelometer. In this study we present an analysis of diurnal and day-to-day variability of the column and near-surface aerosol properties obtained from remote sensing (MFRSR data) and ground-based in situ measurements (SMPS, APS, and nephelometer data). In particular, we show that the observed diurnal variability of the MFRSR aerosol optical depth is strong and comparable with that obtained previously from the AERONET climatology in Mexico City, which has a larger aerosol loading. Moreover, we illustrate how the variability of aerosol properties impacts the direct aerosol radiative forcing at different time scales.

Kassianov, Evgueni I.; Barnard, James C.; Pekour, Mikhail S.; Berg, Larry K.; Fast, Jerome D.; Michalsky, Joseph J.; Lantz, K.; Hodges, G. B.

2013-11-01T23:59:59.000Z

404

Evolution of organic aerosol mass spectra upon heating: implications for OA phase and partitioning behavior  

Science Conference Proceedings (OSTI)

Vacuum Ultraviolet (VUV) photoionization mass spectrometry has been used to measure the evolution of chemical composition for two distinct organic aerosol types as they are passed through a thermodenuder at different temperatures. The two organic aerosol types considered are primary lubricating oil (LO) aerosol and secondary aerosol from the alpha-pinene + O3 reaction (alphaP). The evolution of the VUV mass spectra for the two aerosol types with temperature are observed to differ dramatically. For LO particles, the spectra exhibit distinct changes with temperature in which the lower m/z peaks, corresponding to compounds with higher vapor pressures, disappear more rapidly than the high m/z peaks. In contrast, the alphaP aerosol spectrum is essentially unchanged by temperature even though the particles experience significant mass loss due to evaporation. The variations in the LO spectra are found to be quantitatively in agreement with expectations from absorptive partitioning theory whereas the alphaP spectra suggest that the evaporation of alphaP derived aerosol appears to not be governed by partitioning theory. We postulate that this difference arises from the alphaP particles existing as in a glassy state instead of having the expected liquid-like behavior. To reconcile these observations with decades of aerosol growth measurements, which indicate that OA formation is described by equilibrium partitioning, we present a conceptual model wherein the secondary OA is formed and then rapidly converted from an absorbing form to a non-absorbing form. The results suggest that although OA growth may be describable by equilibrium partitioning theory, the properties of organic aerosol once formed may differ significantly from the properties determined in the equilibrium framework.

UC Davis; Cappa, Christopher D.; Wilson, Kevin R.

2010-10-28T23:59:59.000Z

405

Evaluation of Empirical Aerosol Correlations  

Science Conference Proceedings (OSTI)

This study examined the adequacy of novel scaling and correlation methods used to analyze aerosol behavior in versions 2.0 and 3.0 of the MAAP computer code. The results show that the MAAP 2.0 method suffers from inaccurate scaling. The method used in MAAP 3.0 is theoretically superior and more consistent with experimental data.

1986-12-17T23:59:59.000Z

406

Spacetime thermodynamics and subsystem observables in a kinetically constrained model of glassy systems  

E-Print Network (OSTI)

Spacetime thermodynamics and subsystem observables in aconcept of spacetime thermodynamics [3] is illus- trated indiscussion of space- time thermodynamics by considering the

Jack, Robert L.; Garrahan, Juan P.; Chandler, David

2006-01-01T23:59:59.000Z

407

Effects of stratospheric aerosol surface processes on the LLNL two-dimensional zonally averaged model  

Science Conference Proceedings (OSTI)

We have investigated the effects of incorporating representations of heterogeneous chemical processes associated with stratospheric sulfuric acid aerosol into the LLNL two-dimensional, zonally averaged, model of the troposphere and stratosphere. Using distributions of aerosol surface area and volume density derived from SAGE 11 satellite observations, we were primarily interested in changes in partitioning within the Cl- and N- families in the lower stratosphere, compared to a model including only gas phase photochemical reactions.

Connell, P.S.; Kinnison, D.E.; Wuebbles, D.J. [Lawrence Livermore National Lab., CA (United States); Burley, J.D.; Johnston, H.S. [California Univ., Berkeley, CA (United States). Dept. of Chemistry]|[Lawrence Berkeley Lab., CA (United States)

1992-07-05T23:59:59.000Z

408

Interactions between a Developing Mesoscale Convective System and Its Environment. Part I: Observational Analysis  

Science Conference Proceedings (OSTI)

This paper is the first in a two part series in which the interactions between a growing mesoscale convective system (MCS) and its surrounding environment are investigated. The system studied here developed in northeastern Colorado on 19 July ...

Jason E. Nachamkin; Ray L. McAnelly; William R. Cotton

2000-05-01T23:59:59.000Z

409

Impact of geoengineered aerosols on the troposphere and stratosphere  

Science Conference Proceedings (OSTI)

A coupled chemistry climate model, the Whole Atmosphere Community Climate Model was used to perform a transient climate simulation to quantify the impact of geoengineered aerosols on atmospheric processes. In contrast to previous model studies, the impact on stratospheric chemistry, including heterogeneous chemistry in the polar regions, is considered in this simulation. In the geoengineering simulation, a constant stratospheric distribution of volcanic-sized, liquid sulfate aerosols is imposed in the period 20202050, corresponding to an injection of 2 Tg S/a. The aerosol cools the troposphere compared to a baseline simulation. Assuming an Intergovernmental Panel on Climate Change A1B emission scenario, global warming is delayed by about 40 years in the troposphere with respect to the baseline scenario. Large local changes of precipitation and temperatures may occur as a result of geoengineering. Comparison with simulations carried out with the Community Atmosphere Model indicates the importance of stratospheric processes for estimating the impact of stratospheric aerosols on the Earths climate. Changes in stratospheric dynamics and chemistry, especially faster heterogeneous reactions, reduce the recovery of the ozone layer in middle and high latitudes for the Southern Hemisphere. In the geoengineering case, the recovery of the Antarctic ozone hole is delayed by about 30 years on the basis of this model simulation. For the Northern Hemisphere, a onefold to twofold increase of the chemical ozone depletion occurs owing to a simulated stronger polar vortex and colder temperatures compared to the baseline simulation, in agreement with observational estimates.

Tilmes, S.; Garcia, Rolando R.; Kinnison, Douglas E.; Gettelman, A.; Rasch, Philip J.

2009-06-27T23:59:59.000Z

410

Aerosol-Based Duct Sealing Technology  

NLE Websites -- All DOE Office Websites (Extended Search)

8 8 Aerosol-Based Duct Sealing Technology During the past five years, research has quantified the impacts of residential duct system leakage on HVAC energy consumption and peak electricity demand. A typical house with ducts located in the attic or crawlspace wastes approximately 20% of heating and cooling energy through duct leaks and draws approximately 0.5 KW more electricity during peak cooling periods. A 1991 study indicated that sealing leaks could save close to one Quadrillion Btus per year. (see also Commercializing a New Technology) Because the major cost of sealing leaks in existing air distribution systems is the labor for the location and sealing process, reducing the labor could greatly improve the cost-effectiveness of such a retrofit. Field studies of duct sealing programs performed by HVAC contractors show

411

Multiresolution Ensemble Forecasts of an Observed Tornadic Thunderstorm System. Part II: Storm-Scale Experiments  

Science Conference Proceedings (OSTI)

In Part I, the authors used a full physics, nonhydrostatic numerical model with horizontal grid spacing of 24 km and nested grids of 6- and 3-km spacing to generate the ensemble forecasts of an observed tornadic thunderstorm complex. The ...

Fanyou Kong; Kelvin K. Droegemeier; Nicki L. Hickmon

2007-03-01T23:59:59.000Z

412

High-Resolution Passive Microwave Observations of Convective Systems over the Tropical Pacific Ocean  

Science Conference Proceedings (OSTI)

This paper presents high-resolution passive microwave measurements obtained in the western Pacific warm pool region. These measurements represent the most comprehensive such observations of convection over the tropical oceans to date, and were ...

Gary McGaughey; Edward J. Zipser; Roy W. Spencer; Robbie E. Hood

1996-11-01T23:59:59.000Z

413

Airborne Dual-Doppler Observations of an Intense Frontal System Approaching the Pacific Northwest Coast  

Science Conference Proceedings (OSTI)

Airborne Doppler radar data, collected off the Pacific Northwest coast by a NOAA WP-3D Orion aircraft over an 8-h period on 8 December 1993 during the Coastal Observations and Simulations with Topography experiment, reveal the mesoscale structure ...

Scott A. Braun; Robert A. Houze Jr.; Bradley F. Smull

1997-12-01T23:59:59.000Z

414

Detecting Climate Variations and Change: New Challenges for Observing and Data Management Systems  

Science Conference Proceedings (OSTI)

Several essential aspects of weather observing and the management of weather data are discussed as related to improving knowledge of climate variations and change in the surface boundary layer and the resultant consequences for socioeconomic and ...

Thomas R. Karl; Robert G. Quayle; Pavel Ya Groisman

1993-08-01T23:59:59.000Z

415

A Study of the Remote Control for the East China Sea Seafloor Observation System  

Science Conference Proceedings (OSTI)

Seafloor observatories enable long-term, continuous, real-time, weather-independent, and multidisciplinary scientific observation and research that will promise major breakthroughs in ocean sciences. China has started to establish a seafloor ...

Yang Yu; Huiping Xu; Changwei Xu; Rufu Qin

2012-08-01T23:59:59.000Z

416

Upper ocean processes observed by underwater gliders in the California Current System  

E-Print Network (OSTI)

1980; Chelton and Davis, 1982; Lynn and Bograd , 2002].Lynn and Simpson, 1987, 1990; Todd et al. , 2011a], eddies [DavisLynn and Simpson, 1987; Bray et al. , 1999]. Recent velocity observations [Davis

Todd, Robert E.

2011-01-01T23:59:59.000Z

417

Comparing Local Analysis and Prediction System (LAPS) Assimilations with Independent Observations  

Science Conference Proceedings (OSTI)

Meteorological forcing data are necessary to drive many of the spatial models used to simulate atmospheric, biological, and hydrological processes. Unfortunately, many domains lack sufficient meteorological data and available point observations ...

Christopher A. Hiemstra; Glen E. Liston; Roger A. Pielke Sr.; Daniel L. Birkenheuer; Steven C. Albers

2006-12-01T23:59:59.000Z

418

Inclusion of Linearized Moist Physics in NASAs Goddard Earth Observing System Data Assimilation Tools  

Science Conference Proceedings (OSTI)

Inclusion of moist physics in the linearized version of a weather forecast model is beneficial in terms of variational data assimilation. Further it improves the capability of important tools, such as adjoint based observation impacts and ...

Daniel Holdaway; Ronald Errico; Ronald Gelaro; Jong G. Kim

419

Forecast evaluation of an Observing System Simulation Experiment assimilating both radar and satellite data  

Science Conference Proceedings (OSTI)

In part 1 of this study, Jones et al. (2013a) compared the relative skill of assimilating simulated radar reflectivity and radial velocity observations and satellite 6.95 ?m brightness temperatures (TB) and found that both improved analyses of ...

Thomas A. Jones; Jason A. Otkin; David J. Stensrud; Kent Knopfmeier

420

The Adequacy of Observing Systems in Monitoring the Atlantic Meridional Overturning Circulation and North Atlantic Climate  

Science Conference Proceedings (OSTI)

The Atlantic meridional overturning circulation (AMOC) has an important influence on climate, and yet adequate observations of this circulation are lacking. Here, the authors assess the adequacy of past and current widely deployed routine ...

S. Zhang; A. Rosati; T. Delworth

2010-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol observing systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Properties of Tropical Convection Observed by Millimeter-Wave Radar Systems  

Science Conference Proceedings (OSTI)

This paper describes the results of analysis of over 825 000 profiles of millimeter-wave radar (MWR) reflectivities primarily collected by zenith-pointing surface radars observing tropical convection associated with various phases of activity of ...

Graeme L. Stephens; Norman B. Wood

2007-03-01T23:59:59.000Z

422

Importance of aerosol composition, mixing state, and morphology for heterogeneous ice nucleation: A combined field and laboratory approach  

Science Conference Proceedings (OSTI)

In this study chemical compositions of background aerosol and ice nuclei were examined through laboratory investigations using Raman spectroscopy and field measurements by single-particle mass spectrometry. Aerosol sampling took place at Storm Peak Laboratory in Steamboat Springs, Colorado (elevation of 3210 m). A cascade impactor was used to collect coarse-mode aerosol particles for laboratory analysis by Raman spectroscopy; the composition, mixing state, and heterogeneous ice nucleation activity of individual particles were examined. For in situ analysis of fine-mode aerosol, ice nucleation on ambient particles was observed using a compact ice nucleation chamber. Ice crystals were separated from unactivated aerosol using a pumped counterflow virtual impactor, and ice nuclei were analyzed using particle analysis by laser mass spectrometry. For both fine and coarse modes, the ice nucleating particle fractions were enriched in minerals and depleted in sulfates and nitrates, compared to the background aerosol sampled. The vast majority of particles in both the ambient and ice active aerosol fractions contained a detectable amount of organic material. Raman spectroscopy showed that organic material is sometimes present in the form of a coating on the surface of inorganic particles. We find that some organic-containing particles serve as efficient ice nuclei while others do not. For coarse-mode aerosol, organic particles were only observed to initiate ice formation when oxygen signatures were also present in their spectra.

Baustian, Kelly J.; Cziczo, Daniel J.; Wise, M. A.; Pratt, Kerri; Kulkarni, Gourihar R.; Hallar, Anna G.; Tolbert, Margaret A.

2012-03-30T23:59:59.000Z

423

Observing the evolution of a quantum system that does not evolve  

E-Print Network (OSTI)

This article deals with the problem of gathering information on the time evolution of a single metastable quantum system whose evolution is impeded by the quantum Zeno effect. It has been found it is in principle possible to obtain some information on the time evolution and, depending on the specific system, even to measure its average decay rate, even if the system does not undergo any evolution at all.

Simone De Liberato

2007-05-16T23:59:59.000Z

424

Isolation of ambient aerosols of known critical supersaturation: the differential critical supersaturation separator (DSCS)  

E-Print Network (OSTI)

A field-deployable instrument has been developed that isolates from an ambient aerosol population only those particles that have critical supersaturations, Sc, within a narrow, user-specified, range. This Differential Critical Supersaturation Separator (DScS) is designed to supply one or more particle size and/or composition analyzers to permit the direct examination of the factors that influence the activation properties of ambient aerosols. The DScS consists of two coupled parallel plate continuous flow thermal gradient diffusion cloud chambers housed within a single enclosure. Descriptions of instrument operation, construction and calibration data collected, when pure ammonium sulfate aerosols were injected into the DScS for operation at 0.15%aerosol size distributions and size-resolved hygroscopicity of DScS separated aerosol. The dry diameter (Dp*) of particles sampled in the TDMA system as well as the known Sc prescribed in the DScS were combined in a modified version of K?¶hler Theory to make predictions of particle hygroscopicity. These predictions frequently overestimated the measurements. Further analysis of DScS separated aerosols compares the known particle Sc to a predicted particle Sc, providing insight into particle activation efficiency. Overall, the sampled aerosol exhibited properties that indicate they were more efficient at activation than K?¶hler Theory would predict.

Osborn, Robert John

2003-05-01T23:59:59.000Z

425

The whitehouse effect: Shortwave radiative forcing of climate by anthropogenic aerosols, an overview  

E-Print Network (OSTI)

Abstraet--Loadings of tropospheric aerosols have increased substantially over the past 150 yr as a consequence of industrial activities. These aerosols enhance reflection of solar radiation by the Earth-atmosphere system both directly, by scattering light in clear air and, indirectly, by increasing the reflectivity of clouds. The magnitude of the resultant decrease in absorption of solar radiation is estimated to be comparable on global average to the enhancement in infrared forcing at the tropopause due to increases in concentrations of CO2 and other greenhouse gases over the same time period. Estimates of the aerosol shortwave forcing are quite uncertain, by more than a factor of two about the current best estimates. This article reviews the atmospheric chemistry and microphysical processes that govern the loading and light scattering properties of the aerosol particles responsible for the direct effect and delineates the basis for the present estimates of the magnitude and uncertainty in the resultant radiative forcing. The principal sources of uncertainty are in the loading of anthropogenic aerosols, which is highly variable spatially and temporally because of the relatively short residence time of these aerosols (ca. 1 week) and the episodic removal in precipitation, and in the dependence of light scattering on particle size, and in turn on relative humidity. Uncertainty in aerosol forcing is the greatest source of uncertainty in radiative forcing of climate

Stephen E. Schwartz

1996-01-01T23:59:59.000Z

426

Overview of the 2010 Carbonaceous Aerosols and Radiative Effects Study (CARES)  

Science Conference Proceedings (OSTI)

Substantial uncertainties still exist in the scientific understanding of the possible interactions between urban and natural (biogenic) emissions in the production and transformation of atmospheric aerosol and the resulting impact on climate change. The U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) program's Carbonaceous Aerosol and Radiative Effects Study (CARES) carried out in June 2010 in Central Valley, California, was a comprehensive effort designed to improve this understanding. The primary objective of the field study was to investigate the evolution of secondary organic and black carbon aerosols and their climate-related properties in the Sacramento urban plume as it was routinely transported into the forested Sierra Nevada foothills area. Urban aerosols and trace gases experienced significant physical and chemical transformations as they mixed with the reactive biogenic hydrocarbons emitted from the forest. Two heavily-instrumented ground sites - one within the Sacramento urban area and another about 40 km to the northeast in the foothills area - were set up to characterize the evolution of meteorological variables, trace gases, aerosol precursors, aerosol size, composition, and climate-related properties in freshly polluted and 'aged' urban air. On selected days, the DOE G-1 aircraft was deployed to make similar measurements upwind and across the evolving Sacramento plume in the morning and again in the afternoon. The NASA B-200 aircraft, carrying remote sensing instruments, was also deployed to characterize the vertical and horizontal distribution of aerosols and aerosol optical properties within and around the plume. This overview provides: a) the scientific background and motivation for the study, b) the operational and logistical information pertinent to the execution of the study, c) an overview of key observations and initial results from the aircraft and ground-based sampling platforms, and d) a roadmap of planned data analyses and focused modeling efforts that will facilitate the integration of new knowledge into improved representations of key aerosol processes in climate models.

Zaveri, Rahul A.; Shaw, William J.; Cziczo, D. J.; Schmid, Beat; Ferrare, R.; Alexander, M. L.; Alexandrov, Mikhail; Alvarez, R. J.; Arnott, W. P.; Atkinson, D.; Baidar, Sunil; Banta, Robert M.; Barnard, James C.; Beranek, Josef; Berg, Larry K.; Brechtel, Fred J.; Brewer, W. A.; Cahill, John F.; Cairns, Brian; Cappa, Christopher D.; Chand, Duli; China, Swarup; Comstock, Jennifer M.; Dubey, Manvendra K.; Easter, Richard C.; Erickson, Matthew H.; Fast, Jerome D.; Floerchinger, Cody; Flowers, B. A.; Fortner, Edward; Gaffney, Jeffrey S.; Gilles, Mary K.; Gorkowski, K.; Gustafson, William I.; Gyawali, Madhu S.; Hair, John; Hardesty, Michael; Harworth, J. W.; Herndon, Scott C.; Hiranuma, Naruki; Hostetler, Chris A.; Hubbe, John M.; Jayne, J. T.; Jeong, H.; Jobson, Bertram T.; Kassianov, Evgueni I.; Kleinman, L. I.; Kluzek, Celine D.; Knighton, B.; Kolesar, K. R.; Kuang, Chongai; Kubatova, A.; Langford, A. O.; Laskin, Alexander; Laulainen, Nels S.; Marchbanks, R. D.; Mazzoleni, Claudio; Mei, F.; Moffet, Ryan C.; Nelson, Danny A.; Obland, Michael; Oetjen, Hilke; Onasch, Timothy B.; Ortega, Ivan; Ottaviani, M.; Pekour, Mikhail S.; Prather, Kimberly A.; Radney, J. G.; Rogers, Ray; Sandberg, S. P.; Sedlacek, Art; Senff, Christoph; Senum, Gunar; Setyan, Ari; Shilling, John E.; Shrivastava, ManishKumar B.; Song, Chen; Springston, S. R.; Subramanian, R.; Suski, Kaitlyn; Tomlinson, Jason M.; Volkamer, Rainer M.; Wallace, Hoyt A.; Wang, J.; Weickmann, A. M.; Worsnop, Douglas R.; Yu, Xiao-Ying; Zelenyuk, Alla; Zhang, Qi

2012-08-22T23:59:59.000Z

427

Design and Sampling Characteristics of a New Airborne Aerosol Inlet for Aerosol Measurements in Clouds  

Science Conference Proceedings (OSTI)

Design of a new submicron aerosol inlet (SMAI) for airborne sampling of aerosol particles is introduced and its performance characteristics under a range of sampling conditions are presented. Analysis of inlet performance in clear-air and cloud ...

Lucas Craig; Allen Schanot; Arash Moharreri; David C. Rogers; Suresh Dhaniyala

2013-06-01T23:59:59.000Z

428

The Aerosol Modeling Testbed: A Community Tool to Objectively Evaluate Aerosol Process Modules  

Science Conference Proceedings (OSTI)

The current paradigm of developing and testing new aerosol process modules is haphazard and slow. Aerosol modules are often tested for short simulation periods using limited data so that their overall performance over a wide range of ...

Jerome D. Fast; William I. Gustafson Jr.; Elaine G. Chapman; Richard C. Easter; Jeremy P. Rishel; Rahul A. Zaveri; Georg A. Grell; Mary C. Barth

2011-03-01T23:59:59.000Z

429

Another Look at the Influence of Absorbing Aerosols in Drops on Cloud Absorption: Large Aerosols  

Science Conference Proceedings (OSTI)

Since as early as 1969, solar absorbing aerosols inside of cloud drops have been suggested to influence cloud radiative properties. The absorbing aerosols were invoked to help explain two anomalies: 1) the maximum visible albedo of thick ...

Carynelisa Erlick; Dana Schlesinger

2008-02-01T23:59:59.000Z

430

Assessment of Aerosol Modes Used in the MODIS Ocean Aerosol Retrieval  

Science Conference Proceedings (OSTI)

Coastal and island Aerosol Robotic Network (AERONET) sites are used to determine characteristic aerosol modes over marine environments. They are compared with the assumed modes used in the operational Moderate Resolution Imaging Spectroradiometer (...

Jiacheng Wang; Qiang Zhao; Shengcheng Cui; Chengjie Zhu

2012-12-01T23:59:59.000Z

431

The Joint Modes of the Coupled Atmosphere-Ocean System Observed from 1967 to 1986  

Science Conference Proceedings (OSTI)

Two aspects of the principal oscillation pattern (POP) analysis are used to study the large-scale modes of the coupled atmosphereocean system. First, P0Ps can be considered as the normal modes of the system; one way of studying these normal ...

Jin-Song Xu

1993-05-01T23:59:59.000Z

432

Cloud and Radiative Characteristics of Tropical Deep Convective Systems in Extended Cloud Objects from CERES Observations  

Science Conference Proceedings (OSTI)

The physical and radiative properties of tropical deep convective systems for the period from January to August 1998 are examined with the use of Clouds and the Earths Radiant Energy System Single-Scanner Footprint (SSF) data from the Tropical ...

Zachary A. Eitzen; Kuan-Man Xu; Takmeng Wong

2009-11-01T23:59:59.000Z

433

Diesel Aerosol Sampling in the Atmosphere  

DOE Green Energy (OSTI)

The University of Minnesota Center for Diesel Research along with a research team including Caterpillar, Cummins, Carnegie Mellon University, West Virginia University (WVU), Paul Scherrer Institute in Switzerland, and Tampere University in Finland have performed measurements of Diesel exhaust particle size distributions under real-world dilution conditions. A mobile aerosol emission laboratory (MEL) equipped to measure particle size distributions, number concentrations, surface area concentrations, particle bound PAHs, as well as CO 2 and NO x concentrations in real time was built and will be described. The MEL was used to follow two different Cummins powered tractors, one with an older engine (L10) and one with a state-of-the-art engine (ISM), on rural highways and measure particles in their exhaust plumes. This paper will describe the goals and objectives of the study and will describe representative particle size distributions observed in roadway experiments with the truck powered by the ISM engine.

David Kittelson; Jason Johnson; Winthrop Watts; Qiang Wei; Marcus Drayton; Dwane Paulsen; Nicolas Bukowiecki

2000-06-19T23:59:59.000Z

434

ARM - PI Product - Direct Aerosol Forcing Uncertainty  

NLE Websites -- All DOE Office Websites (Extended Search)

ProductsDirect Aerosol Forcing Uncertainty ProductsDirect Aerosol Forcing Uncertainty 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 Site(s) NSA SGP TWP General Description 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

435

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

NLE Websites -- All DOE Office Websites (Extended Search)

govCampaignsTwo-Column Aerosol Project (TCAP) govCampaignsTwo-Column Aerosol Project (TCAP) Campaign Links TCAP website 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 Aerosol Effects on Cloud Formation 2013.02.04, Cziczo, AMF Two-Column Aerosol Project (TCAP): CU GMAX-DOAS Deployment 2012.07.15, Volkamer, AMF Two-Column Aerosol Project (TCAP): Aerosol Light Extinction Measurements 2012.07.15, Dubey, AMF Two-Column Aerosol Project (TCAP): Aerial Campaign 2012.07.07, Berg, AAF Two-Column Aerosol Project (TCAP): Aerodynamic Particle Sizer 2012.07.01, Berg, AMF Two-Column Aerosol Project (TCAP): KASPRR Engineering Tests 2012.07.01, Mead, AMF Two-Column Aerosol Project (TCAP): Airborne HSRL and RSP Measurements

436

Using MODIS and AERONET to Determine GCM Aerosol Size  

Science Conference Proceedings (OSTI)

Aerosol size is still a poorly constrained quantity in general circulation models (GCMs). By using the modal radii of the coarse and fine mode retrieved from 103 stations in the Aerosol Robotic Network (AERONET) and the fine mode aerosol optical ...

Glen Lesins; Ulrike Lohmann

2006-04-01T23:59:59.000Z

437

AEROSOL ANALYSIS FOR THE REGIONAL AIR POLLUTION STUDY - FINAL REPORT  

E-Print Network (OSTI)

Beta-Gauge Methods Applied to Aerosol Samples." Submitted toHusar and B.Y.H. Liu. "The Aerosol Size Distribution of LosAngeles Smog." In: Aerosols and Atmospheric Chemistry, G.M.

Jaklevic, J.M.

2010-01-01T23:59:59.000Z

438

Distinguishing Aerosol Impacts on Climate Over the Past Century  

E-Print Network (OSTI)

Table 1. Aerosol Characteristics Species Emissions Burdenc and h), IE (d, i) and BAE (e, f). List of Tables AerosolEmission of trace gases and aerosols from biomass burning,

Koch, Dorothy

2009-01-01T23:59:59.000Z

439

OH-initiated heterogeneous aging of highly oxidized organic aerosol  

E-Print Network (OSTI)

P. ; Jimenez, J. L. Aerosol Science and Technology 2004, 38,A. G. Highly dispersed aerosols; Halsted Press, New York,highly oxidized organic aerosol Sean H. Kessler 1 , Theodora

Kessler, Sean H.

2013-01-01T23:59:59.000Z

440

SPURIOUS SULFATE FORMATION ON COLLECTED AMBIENT AEROSOL SAMPLES  

E-Print Network (OSTI)

FORMATION ON COLLECTED AMBIENT AEROSOL SAMPLES B. W. Loo, R.FORMATION ON COLLECTED AMBIENT AEROSOL SAMPLES Billy W. Lao,ON COLLECTED AMBIENT AEROSOL SAMPLES* _B_il_l~y ___ W_. _L~o

Loo, B.W.

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol observing systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Coupling Aerosol-Cloud-Radiative Processes in the WRF-Chem Model: Investigating the Radiative Impact of Elevated Point Sources  

Science Conference Proceedings (OSTI)

The local and regional influence of elevated point sources on summertime aerosol forcing and cloud-aerosol interactions in northeastern North America was investigated using the WRF-Chem community model. The direct effects of aerosols on incoming solar radiation were simulated using existing modules to relate aerosol sizes and chemical composition to aerosol optical properties. Indirect effects were simulated by adding a prognostic treatment of cloud droplet number and adding modules that activate aerosol particles to form cloud droplets, simulate aqueous phase chemistry, and tie a two-moment treatment of cloud water (cloud water mass and cloud droplet number) to an existing radiation scheme. Fully interactive feedbacks thus were created within the modified model, with aerosols affecting cloud droplet number and cloud radiative properties, and clouds altering aerosol size and composition via aqueous processes, wet scavenging, and gas-phase-related photolytic processes. Comparisons of a baseline simulation with observations show that the model captured the general temporal cycle of aerosol optical depths (AODs) and produced clouds of comparable thickness to observations at approximately the proper times and places. The model slightly overpredicted SO2 mixing ratios and PM2.5 mass, but reproduced the range of observed SO2 to sulfate aerosol ratios, suggesting that atmospheric oxidation processes leading to aerosol sulfate formation are captured in the model. The baseline simulation was compared to a sensitivity simulation in which all emissions at model levels above the surface layer were set to zero, thus removing stack emissions. Instantaneous, site-specific differences for aerosol and cloud related properties between the two simulations could be quite large, as removing above-surface emission sources influenced when and where clouds formed within the modeling domain. When summed spatially over the finest resolution model domain (the extent of which corresponds to the typical size of a single GCM grid cell) and temporally over a three day analysis period, total rainfall in the sensitivity simulation increased by 31% over that in the baseline simulation. Fewer optically thin clouds, arbitrarily defined as a cloud exhibiting an optical depth less than 1, formed in the sensitivity simulation. Domain-averaged AODs dropped from 0.46 in the baseline simulation to 0.38 in the sensitivity simulation. The overall net effect of additional aerosols attributable to primary particulates and aerosol precursors from point source emissions above the surface was a domain-averaged reduction of 5 W m-2 in mean daytime downwelling shortwave radiation.

Chapman, Elaine G.; Gustafson, William I.; Easter, Richard C.; Barnard, James C.; Ghan, Steven J.; Pekour, Mikhail S.; Fast, Jerome D.

2009-02-01T23:59:59.000Z

442

The Integrated Sounding System: Description and Preliminary Observations from TOGA COARE  

Science Conference Proceedings (OSTI)

An Integrated Sounding System (ISS) that combines state-of- the-art remote and in situ sensors into a single transportable facility has been developed jointly by the National Center for Atmospheric Research (NCAR) and the Aeronomy laboratory of ...

David Parsons; Walter Dabberdt; Harold Cole; Terrence Hock; Charles Martin; Anne-Leslie Barrett; Erik Miller; Michael Spowart; Michael Howard; Warner Ecklund; David Carter; Kenneth Gage; John Wilson

1994-04-01T23:59:59.000Z

443

The Effect of Environmental Conditions on Tropical Deep Convective Systems Observed from the TRMM Satellite  

Science Conference Proceedings (OSTI)

This study uses measurements of radiation and cloud properties taken between January and August 1998 by three Tropical Rainfall Measuring Mission (TRMM) instruments, the Clouds and the Earths Radiant Energy System (CERES) scanner, the TRMM ...

Bing Lin; Bruce A. Wielicki; Patrick Minnis; Lin Chambers; Kuan-Man Xu; Yongxiang Hu; Alice Fan

2006-11-01T23:59:59.000Z

444

Characteristics of Vertical Velocity Cores in Different Convective Systems Observed over Gadanki, India  

Science Conference Proceedings (OSTI)

The Indian mesospherestratospheretroposphere (MST) radar measurements during the passage of 60 convective systems are used to study the vertical air velocity (w) characteristics of tropical convection. The up- and downdraft cores and various ...

K. N. Uma; T. Narayana Rao

2009-03-01T23:59:59.000Z

445

On possibility to observe new fundamental forces in open quantum systems  

E-Print Network (OSTI)

A possibility and peculiarities of registration of new fundamental forces in open quantum systems are discussed. As a possible example, variations of decay rates of radioactive elements reported in scientific literature are considered in detail.

B. F. Kostenko; M. Z. Yuriev

2006-05-12T23:59:59.000Z

446

Mobile Integrated Profiler System (MIPS) Observations of Low-Level Convergent Boundaries during IHOP  

Science Conference Proceedings (OSTI)

Characteristics of convergent boundary zones (CBZs) sampled by the Mobile Integrated Profiling System (MIPS) during the 2002 International H2O Project (IHOP_2002) are presented. The MIPS sensors (915-MHz wind profiler, 12-channel microwave ...

Haldun Karan; Kevin Knupp

2006-01-01T23:59:59.000Z

447

Multiwavelength Observations of a Developing Cloud System: The FIRE II 26 November 1991 Case Study  

Science Conference Proceedings (OSTI)

Simultaneous multiwavelength measurements of a developing cloud system were obtained by NOAA Doppler lidar, Doppler radar, Fourier transform infrared interferometer, and microwave and infrared radiometers on 26 November 1991. The evolution of the ...

J. M. Intrieri; W. L. Eberhard; T. Uttal; J. A. Shaw; J. B. Snider; Y. Han; B. W. Orr; S. Y. Matrosov

1995-12-01T23:59:59.000Z

448

The University of South Alabama Mesonet and Coastal Observing System: A Technical and Statistical Overview  

Science Conference Proceedings (OSTI)

The University of South Alabama Mesonet consists of 26 sites across the north-central Gulf of Mexico coast. Although the original purpose of the mesonet was monitoring landfalling tropical systems, meteorological data are collected and ...

Sytske K. Kimball; Madhuri S. Mulekar; Shailer Cummings; Jack Stamates

2010-09-01T23:59:59.000Z

449

Direct and semidirect aerosol effects of southern African biomass burning aerosol  

E-Print Network (OSTI)

Direct and semidirect aerosol effects of southern African biomass burning aerosol Naoko Sakaeda,1 2011; published 21 June 2011. [1] Direct and semidirect radiative effects of biomass burning aerosols static stability. Over the entire region the overall TOA radiative effect from the biomass burning

Wood, Robert

450

The impact of covariance localization for radar data on enKF analyses of a developing MCS: Observing system simulation experiments  

Science Conference Proceedings (OSTI)

Several observing system simulation experiments (OSSEs) were performed to assess the impact of covariance localization of radar data on ensemble Kalman filter (EnKF) analyses of a developing convective system. Simulated WSR-88D radar observations ...

Ryan A. Sobash; David J. Stensrud

451

Top-of-Atmosphere Direct Radiative Effect of Aerosols over the Tropical Oceans from the Clouds and the Earth's Radiant Energy System (CERES) Satellite Instrument  

Science Conference Proceedings (OSTI)

Nine months of the Clouds and the Earth's Radiant Energy System (CERES)/Tropical Rainfall Measuring Mission (TRMM) broadband fluxes combined with the TRMM visible infrared scanner (VIRS) high-resolution imager measurements are used to estimate ...

Norman G. Loeb; Seiji Kato

2002-06-01T23:59:59.000Z

452

Composition and Reactions of Atmospheric Aerosol Particles  

NLE Websites -- All DOE Office Websites (Extended Search)

change. Tiny Specks with Large Effects Most people equate aerosols with hairspray and household cleaning products, but a large portion of these microscopic particles floating...

453

Radiative and climate impacts of absorbing aerosols  

E-Print Network (OSTI)

over the southwest summer monsoon region, Meteorol. Atmos.Absorbing aerosols and summer monsoon evolution over SouthK. M. Kim (2006), Asian summer monsoon anomalies induced by

Zhu, Aihua

2010-01-01T23:59:59.000Z

454

Carbonaceous Aerosol Study Using Advanced Particle Instrumentation  

E-Print Network (OSTI)

range transport of biomass combustion aerosols. Environ.6 6.1 Introduction Biomass combustion emissions contributeparticles from the combustion of biomass fuels. Environ.

Qi, Li

2010-01-01T23:59:59.000Z

455

Sensitivity of the First Indirect Aerosol Effect to an Increase of Cloud Droplet Spectral Dispersion with Droplet Number Concentration  

Science Conference Proceedings (OSTI)

Observations show that an increase in anthropogenic aerosols leads to concurrent increases in the cloud droplet concentration and the relative dispersion of the cloud droplet spectrum, other factors being equal. It has been suggested that the ...

Leon D. Rotstayn; Yangang Liu

2003-11-01T23:59:59.000Z