Sample records for aerosol observing systems

  1. Aerosol Observing System (AOS) Handbook

    SciTech Connect (OSTI)

    Jefferson, A

    2011-01-17T23:59:59.000Z

    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 earth’s 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.

  2. Aerosol observing system platform integration and AAF instrumentation

    SciTech Connect (OSTI)

    Springston, S.; Sedlacek, A.

    2010-03-15T23:59:59.000Z

    As part of the federal government’s 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, 2010–March 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 2011–April 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.

  3. Atmospheric Aerosol Systems | EMSL

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

    Science Themes Atmospheric Aerosol Systems Overview Atmospheric Aerosol Systems Biosystem Dynamics & Design Energy Materials & Processes Terrestrial & Subsurface Ecosystems...

  4. EMSL - Atmospheric Aerosol Systems

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

    scienceatmospheric The Atmospheric Aerosol Systems Science Theme focuses on understanding the chemistry, physics and molecular-scale dynamics of aerosols for model...

  5. Global observations of desert dust and biomass burning aerosols

    E-Print Network [OSTI]

    Graaf, Martin de

    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 and desert dust observations from GOME and SCIAMACHY · Conclusions and Outlook #12; · Absorbing Aerosol

  6. Satellite observations of the seasonal cycles of absorbing aerosols in Africa

    E-Print Network [OSTI]

    Graaf, Martin de

    Satellite observations of the seasonal cycles of absorbing aerosols in Africa related to monsoon system and aerosol loading is studied using multi-year satellite observations of UV-absorbing aerosols and rain gauge measurements. The seasonal variation of the aerosol distribution is clearly linked

  7. Retrieval of Non-Spherical Dust Aerosol Properties from Satellite Observations

    E-Print Network [OSTI]

    Huang, Xin

    2013-08-01T23:59:59.000Z

    An accurate and generalized global retrieval algorithm from satellite observations is a prerequisite to understand the radiative effect of atmospheric aerosols on the climate system. Current operational aerosol retrieval algorithms are limited...

  8. A New Aerosol Flow System for Photochemical and Thermal Studies...

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

    Aerosol Flow System for Photochemical and Thermal Studies of Tropospheric Aerosols. A New Aerosol Flow System for Photochemical and Thermal Studies of Tropospheric Aerosols....

  9. Development of plutonium aerosol fractionation system

    E-Print Network [OSTI]

    Mekala, Malla R.

    1993-01-01T23:59:59.000Z

    microns), inhalation accidents occurring during maintenance operations can be expected to result in long term retention of 20% to 30% of the inhaled aerosol. Thind"' performed experiments over a span of one year to observe the consistency...DEVELOPMENT OF A PLUTONIUM AEROSOL FRACTIONATION SYSTEM A Thesis by MALLA R. MEKALA Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE August...

  10. Aerosol Observing System Upgraded

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office511041cloth DocumentationProducts (VAP) VAP7-0973 1BP-14Scripting for AdvancedSensitivitySensitivity of2

  11. Aerosol Retrieval Using Remote-sensed Observations

    E-Print Network [OSTI]

    Wang, Yueqing

    2012-01-01T23:59:59.000Z

    1.2 Aerosols Impacts on HumanBayesian Approach for Aerosol Retrieval Using MISR Data 2.1for Including a Richer Variety of Aerosol Compositions . 2.5

  12. Development of plutonium aerosol fractionation system 

    E-Print Network [OSTI]

    Mekala, Malla R.

    1993-01-01T23:59:59.000Z

    DEVELOPMENT OF A PLUTONIUM AEROSOL FRACTIONATION SYSTEM A Thesis by MALLA R. MEKALA Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE August... 1993 Major Subject: Mechanical Engineering DEVELOPMENT OP A PLUTONIUM AEROSOL FRACTIONATION SYSTEM A Thesis by MALLA R. MEKALA Approved as to style and content by: A. R. McFarland (Chair of Committee) N. K. Anand (Mer toer) (', & C. B...

  13. ARM - Mobile Aerosol Observing System

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadap Documentation TDMADAP : XDCnarrowbandheat flux ARMMeasurementsMethane Gas

  14. ARM - Surface Aerosol Observing System

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadap Documentation TDMADAP :ProductsVaisalaAlaskaInstruments NSASteering

  15. Global observations of UV-absorbing aerosols from ERS-2/GOME Data

    E-Print Network [OSTI]

    Graaf, Martin de

    Global observations of UV-absorbing aerosols from ERS-2/GOME Data Martin de Graaf Piet Stammes Absorbing Aerosol Index ­ Theory GOME AAI results Conclusions & Outlook #12; Absorbing Aerosol Index; Rayleigh (multiple) scattering clouds aerosols surface Top Of Atmosphere incoming radiation outgoing

  16. Global observations and spectral characteristics of desert dust and biomass burning aerosols

    E-Print Network [OSTI]

    Graaf, Martin de

    Global observations and spectral characteristics of desert dust and biomass burning aerosols M. de (UV) absorbing aerosols, mainly desert dust and biomass burning aerosols. The AAI is not an aerosol quantity, but a radiation difference in the UV. Its main advantages are its insensitivity to scattering

  17. Longwave radiative forcing of Saharan dust aerosols estimated from MODIS, MISR, and CERES observations on Terra

    E-Print Network [OSTI]

    Christopher, Sundar A.

    observations from the Advanced Very High Resolution Radiometer (AVHRR) [Ackerman and Chung, 1992] and the Total's Radiant Energy System (CERES) instruments onboard the Terra satellite; we present a new technique prevalent in the tropics [Prospero, 1999], dust aerosols are effective in reflecting solar energy back

  18. Development of the Captive Aerosol Growth and Evolution Chamber System

    E-Print Network [OSTI]

    Antonietti, Carlos G

    2014-08-28T23:59:59.000Z

    The Captive Aerosol Growth and Evolution (CAGE) Chamber System is an tool designed to study the evolution of aerosols under conditions identical or similar to those of the surrounding environment. Our motivation was to quantify the sensitivity...

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

    SciTech Connect (OSTI)

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

    2011-02-08T23:59:59.000Z

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

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

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's Possible for RenewableSpeeding accessSpeeding access(SC)Gas and OilPhaseObservationAerosol

  1. Aerosol behavior experiments on light water reactor primary systems

    SciTech Connect (OSTI)

    Rahn, F.J.; Collen, J.; Wright, A.L.

    1988-05-01T23:59:59.000Z

    The results of three experimental programs relevant to the behavior of aerosols in the primary systems of light water reactors (LWRs) are presented. These are the Large-Scale Aerosol Transport Test programs performed at the Marviken test facility in Sweden, parts of the LWR Aerosol Containment Experiments (LACE) performed at the Hanford Engineering Development Laboratory, and the TRAP-MELT validation project performed at Oak Ridge National Laboratory. The Marviken experiments focused on the behavior of aerosols released from fuel and structural materials in a damaged core. Data on the transport of these aerosols and their physical characteristics were obtained in five experiments that simulated LWR primary systems. The LACE program data include results from the containment bypass accident tests, which focused on aerosol transport in pipes. The TRAP-MELT validation project data include results from two types of experiments: (a) aerosol transport tests to investigate aerosol wall plateout in a vertical pipe geometry and (b) aerosol resuspension tests to provide a data base from which analytical models can be developed. Typical results from these programs are presented and discussed.

  2. Aerosol mass spectrometry systems and methods

    DOE Patents [OSTI]

    Fergenson, David P.; Gard, Eric E.

    2013-08-20T23:59:59.000Z

    A system according to one embodiment includes a particle accelerator that directs a succession of polydisperse aerosol particles along a predetermined particle path; multiple tracking lasers for generating beams of light across the particle path; an optical detector positioned adjacent the particle path for detecting impingement of the beams of light on individual particles; a desorption laser for generating a beam of desorbing light across the particle path about coaxial with a beam of light produced by one of the tracking lasers; and a controller, responsive to detection of a signal produced by the optical detector, that controls the desorption laser to generate the beam of desorbing light. Additional systems and methods are also disclosed.

  3. Statistical analysis of 4-year observations of aerosol sizes in a semi-rural continental environment

    E-Print Network [OSTI]

    Lee, Shan-Hu

    Statistical analysis of 4-year observations of aerosol sizes in a semi-rural continental. Introduction Formation of new aerosol particles via gas-to-particle conver- sion is an important process, which to understanding how new particle formation (NPF) processes lead to formation of cloud condensation nuclei (CCN

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

    E-Print Network [OSTI]

    Kroll, Jesse

    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, ...

  5. Observed Holiday Aerosol Reduction and Temperature Cooling over East Asia

    SciTech Connect (OSTI)

    Gong, Daoyi; Wang, Wenshan; Qian, Yun; Bai, Wenbing; Guo, Yuanxi; Mao, Rui

    2014-06-16T23:59:59.000Z

    The Spring Festival air pollution in China was investigated using the long-term observations from 2001-2012 over 323 stations. During the Spring Festival with nearly half of urban population leaving the cities for holidays, the particulate matter (PM10) concentration is about 24.5?gm-3 (23%) lower than normal days. Associated with the national-wide burning of firework, the PM10 concentration sharply increases to 123.8?gm-3 at Chinese New Year Day (increment of 35%). Similar to PM10, the SO2 and NO2 decrease from high values in normal days to a holiday minimum with reduction of 23.3% and 30.6%, respectively. The NO2 has no peak in New Year Day because of the different emission source. The night mean and minimum temperature co-vary with PM10. Both nighttime mean and minimum temperature decrease by about 2.1°C during the holidays. And in association with the pollution jump at New Year Day the night temperature simultaneously increase by about 0.89°C. The in-phase co-variations between PM10 and night temperature suggest an overall warming effect of holiday aerosol during winter in China.

  6. Estimating the Radiative Forcing of Carbonaceous Aerosols over California based on Satellite and Ground Observations

    SciTech Connect (OSTI)

    Xu, Yangyang; Bahadur, R.; Zhao, Chun; Leung, Lai-Yung R.

    2013-10-04T23:59:59.000Z

    Carbonaceous aerosols have the potential to impact climate both through directly absorbing incoming solar radiation, and by indirectly affecting the cloud layer. To quantify this impact recent modeling studies have made great efforts to simulate both the spatial and temporal distribution of carbonaceous aerosols and their associated radiative forcing. This study makes the first observationally constrained assessment of the direct radiative forcing of carbonaceous aerosols at a regional scale over California. By exploiting multiple observations (including ground sites and satellites), we constructed the distribution of aerosol optical depths and aerosol absorption optical depths over California for a ten-year period (2000-2010). The total solar absorption was then partitioned into contributions from elemental carbon (EC), organic carbon (OC) and dust aerosols using a newly developed scheme. Aerosol absorption optical depth due to carbonaceous aerosols (EC and OC) at 440 nm is 50%-200% larger than natural dust, with EC contributing the bulk (70%-90%). Observationally constrained EC absorption agrees reasonably well with estimates from regional transport models, but the model underestimates the OC AAOD by at least 50%. We estimate that the TOA warming from carbonaceous aerosols is 0.7 W/m2 and the TOA forcing due to OC is close to zero. The atmospheric heating of carbonaceous aerosols is 2.2-2.9 W/m2, of which EC contributed about 80-90%. The atmospheric heating due to OC is estimated to be 0.1 to 0.4 W/m2, larger than model simulations. The surface brightening due to EC reduction over the last two decades is estimated to be 1.5-3.5 W/m2.

  7. Aerosol loading in the Southeastern United States: reconciling surface and satellite observations

    E-Print Network [OSTI]

    Ford, B.

    We investigate the seasonality in aerosols over the Southeastern United States using observations from several satellite instruments (MODIS, MISR, CALIOP) and surface network sites (IMPROVE, SEARCH, AERONET). We find that ...

  8. Determination of particulate lead using aerosol mass spectrometry: MILAGRO/MCMA-2006 observations

    E-Print Network [OSTI]

    Salcedo, D.

    We report the first measurements of particulate lead (Pb) from Aerodyne Aerosol Mass Spectrometers, which were deployed in and around Mexico City during the Megacity Initiative: Local and Global Research Observations ...

  9. Direct observations of the effects of aerosol loading on net ecosystem CO2 exchanges over different landscapes

    E-Print Network [OSTI]

    Niyogi, Dev

    radiation; effect of cloud cover; and effect of high and low aerosol optical depths (AOD). Results indicateDirect observations of the effects of aerosol loading on net ecosystem CO2 exchanges over different, and croplands) with collocated aerosol and surface radiation measurements were analyzed for high and low diffuse

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

    SciTech Connect (OSTI)

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

    2014-09-23T23:59:59.000Z

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

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

    E-Print Network [OSTI]

    Glen, Crystal

    2012-02-14T23:59:59.000Z

    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...

  12. Aerosol Remote Sealing System - Energy Innovation Portal

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office511041cloth DocumentationProducts (VAP) VAP7-0973 1BP-14Scripting forForcing During Spring-SummerAerosol

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

    E-Print Network [OSTI]

    Axisa, Duncan

    2011-02-22T23:59:59.000Z

    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...

  14. A geostatistical data fusion technique for merging remote sensing and groundbased observations of aerosol optical thickness

    E-Print Network [OSTI]

    Michalak, Anna M.

    A geostatistical data fusion technique for merging remote sensing and groundbased observations. Braverman, and C. E. Miller (2010), A geostatistical data fusion technique for merging remote sensing cloud properties (the aerosol indirect effect), producing a net cooling of the Earth surface, and can

  15. Observations of new aerosol particle formation in a tropical urban Raghu Betha a

    E-Print Network [OSTI]

    Spracklen, Dominick

    -19, Singapore 117576, Singapore b School of Earth and Environment, University of Leeds, Leeds LS2 9JT, United. These nucleation events were frequently observed during the SW monsoon period, but were rarely seen during the NE events were suppressed. Ã? 2013 Elsevier Ltd. All rights reserved. 1. Introduction Atmospheric aerosols

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

    E-Print Network [OSTI]

    A. M. Selvam

    2011-07-25T23:59:59.000Z

    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.

  17. Aerosols in the Caribbean MidAtlantic Region as Observed with the EOS Moderate Resolution Imaging Spectroradiometer (MODIS)

    E-Print Network [OSTI]

    Gilbes, Fernando

    Aerosols in the Caribbean MidAtlantic Region as Observed with the EOS Moderate Resolution Imaging the year, changes in precipitation patterns and greater health risks for the Caribbean region during the spring months. Keywords: MODIS, MODIS Conversion Toolkit, aerosols, Caribbean region INTRODUCTION

  18. Alveolar targeting of aerosol pentamidine. Toward a rational delivery system

    SciTech Connect (OSTI)

    Simonds, A.K.; Newman, S.P.; Johnson, M.A.; Talaee, N.; Lee, C.A.; Clarke, S.W. (Royal Free Hospital, London (England))

    1990-04-01T23:59:59.000Z

    Nebulizer systems that deposit a high proportion of aerosolized pentamidine on large airways are likely to be associated with marked adverse side effects, which may lead to premature cessation of treatment. We have measured alveolar deposition and large airway-related side effects (e.g., cough, breathlessness, and effect on pulmonary function) after aerosolization of 150 mg pentamidine isethionate labeled with {sup 99m}Tc-Sn-colloid. Nine patients with AIDS were studied using three nebulizer systems producing different droplet size profiles: the Acorn System 22, Respirgard II, and Respirgard II with the inspiratory baffle removed. Alveolar deposition was greatest and side effects least with the nebulizer producing the smallest droplet size profile (Respirgard II), whereas large airway-related side effects were prominent and alveolar deposition lowest with the nebulizer producing the largest droplet size (Acorn System 22). Values for alveolar deposition and adverse airway effects were intermediate using the Respirgard with inspiratory baffle removed, thus indicating the importance of the baffle valve in determining droplet size. Addition of a similar baffle valve to the Acorn System 22 produced a marked improvement in droplet size profile. Selection of a nebulizer that produces an optimal droplet size range offers the advantage of enhancing alveolar targeting of aerosolized pentamidine while reducing large airway-related side effects.

  19. Air Observe System

    E-Print Network [OSTI]

    Alexander Bolonkin

    2007-01-10T23:59:59.000Z

    This manuscript contains a description and basic principles for observing inaccessible areas using low cost, easily deployed equipment. The basic premise is to suspend a tiny video camera at an altitude of 10 - 200 meters over the area to be surveyed. The TV camera supports at altitude by wind or balloon. The technical challenges regard the means by which the camera is suspended. Such a system may be used by military or police forces or by civil authorities for rescue missions or assessment of natural disasters. The method may be further developed for military applications by integrating the surveillance task with deployment of munitions. Key words: air observer, air suspended system, low altitude video observer.

  20. Observational Studies of Atmospheric Aerosols over Bozeman, Montana, Using a Two-Color Lidar, a Water Vapor DIAL, a Solar Radiometer,

    E-Print Network [OSTI]

    Shaw, Joseph A.

    Observational Studies of Atmospheric Aerosols over Bozeman, Montana, Using a Two-Color Lidar form 24 June 2010) ABSTRACT Coordinated observational data of atmospheric aerosols were collected over-based nephelometer. The optical properties and spatial distribution of the atmospheric aerosols were inferred from

  1. Quantifying aerosol direct radiative effect with Multiangle Imaging Spectroradiometer observations: Top-of-atmosphere albedo change by aerosols based on land surface types

    E-Print Network [OSTI]

    Chen, Yang; Li, Qinbin; Kahn, Ralph A; Randerson, James T; Diner, David J

    2009-01-01T23:59:59.000Z

    coincident MISR and MODIS aerosol optical depths over land2003), Estimates of the spectral aerosol single scatteringalbedo and aerosol radiative effects during SAFARI 2000, J.

  2. Transboundary Secondary Organic Aerosol in Western Japan: An Observed Limitation of the f44 Oxidation Indicator

    E-Print Network [OSTI]

    Irei, Satoshi; Sadanaga, Yasuhiro; Miyoshi, Takao; Arakaki, Tekemitsu; Sato, Kei; Kaneyasu, Naoki; Bandow, Hiroshi; Hatakeyama, Shiro

    2015-01-01T23:59:59.000Z

    To obtain evidence for secondary organic aerosol formation during the long range transport of air masses over the East China Sea, we conducted field measurements in March 2012 at the Fukue atmospheric monitoring station, Nagasaki, in western Japan. The relative abundance of m/z 44 in fine organic aerosol mass spectra (f44) was measured by an Aerodyne aerosol chemical speciation monitor. The stable carbon isotope ratio (d13C) of low volatile water soluble organic carbon (LV-WSOC) in the daily filter samples of total suspended particulate matter was also analyzed using an elemental analyzer coupled with an isotope ratio mass spectrometer. Additionally, in situ measurements of NOx and NOy were performed using NOx and NOy analyzers. The measurements showed that, unlike the systematic trends observed in a previous field study, a scatter plot for d13C of LV-WSOC versus f44 indicated a random variation. Comparison of f44 with the photochemical age estimated by the NOx to NOy ratio revealed that the f44 values distri...

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

    SciTech Connect (OSTI)

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

    2010-05-12T23:59:59.000Z

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

  4. CCN Activity of Organic Aerosols Observed Downwind of Urban Emissions during CARES

    SciTech Connect (OSTI)

    Mei, Fan; Setyan, Ari; Zhang, Qi; Wang, J. X.

    2013-12-17T23:59:59.000Z

    During the Carbonaceous Aerosols and Radiative Effects Study (CARES), activation fraction of size-resolved aerosol particles and aerosol chemical composition were characterized at the T1 site (~60 km downwind of Sacramento, California) from 10 June to 28 June 2010. The hygroscopicity of CCN-active particles (kCCN) with diameter from 100 to 170 nm, derived from the size-resolved activated fraction, varied from 0.10 to 0.21, with an average of 0.15, which was substantially lower than that proposed for continental sites in earlier studies. The low kCCN value was due to the high organic volume fraction, averaged over 80% at the T1 site. The derived kCCN exhibited little diurnal variation, consistent with the relatively constant organic volume fraction observed. At any time, over 90% of the size selected particles with diameter between 100 and 171nm were CCN active, suggesting most particles within this size range were aged background particles. Due to the large organic volume fraction, organic hygroscopicity (korg) strongly impacted particle hygroscopicity and therefore calculated CCN concentration. For vast majority of the cases, an increase of korg from 0.03 to 0.18, which are within the typical range, doubled the calculated CCN concentration. Organic hygroscopicity was derived from kCCN and aerosol chemical composition, and its variations with the fraction of total organic mass spectral signal at m/z 44 (f44) and O:C were compared to results from previous studies. Overall, the relationships between korg and f44 are quite consistent for organic aerosol (OA) observed during field studies and those formed in smog chamber. Compared to the relationship between korg and f44, the relationship between korg and O:C exhibits more significant differences among different studies, suggesting korg may be better parameterized using f44. A least squares fit yielded korg = 2.10 (±0.07) × f44 ?0.11 (±0.01) with the Pearson R2 value of 0.71. One possible explanation for the stronger correlation between korg and f44 is that the m/z 44 signal (mostly contributed by the CO+2 ion) is more closely related to organic acids, which may dominate the overall korg due to their relatively high water solubility and hygroscopicity.

  5. Development of the Captive Aerosol Growth and Evolution Chamber System 

    E-Print Network [OSTI]

    Antonietti, Carlos G

    2014-08-28T23:59:59.000Z

    that are alternated between the two using 3-way valves. There are two Teflon ports for gases and a stainless steel port for aerosol injection and withdrawal. The walls of the room are covered with UV-reflective aluminum panels. A 54 kW air conditioning system... W black lights. The walls of the room are covered with reflective aluminum panels. During operation the inlet and outlet flow rates are matched. The University of California at Riverside environmental chamber consists of two ~90 m3 Teflon bags...

  6. Aerosol Single-Scattering Albedo and Asymmetry Parameter from MFRSR Observations during the ARM Aerosol IOP 2003

    SciTech Connect (OSTI)

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

    2007-06-15T23:59:59.000Z

    Multi-filter Rotating Shadowband Radiometers (MFRSRs) provide routine measurements of the aerosol optical depth ( << OLE Object: Microsoft Equation 3.0 >> ) at six wavelengths (0.415, 0.5, 0.615, 0.673, 0.870 and 0.94  << OLE Object: Picture (Metafile) >> ). The single-scattering albedo ( << OLE Object: Microsoft Equation 3.0 >> ) is typically estimated from the MFRSR measurements by assuming the asymmetry parameter ( << OLE Object: Microsoft Equation 3.0 >> ). In most instances, however, it is not easy to set an appropriate value of << OLE Object: Microsoft Equation 3.0 >> due to its strong temporal and spatial variability. Here, we introduce and validate an updated version of our retrieval technique that allows one to estimate simultaneously << OLE Object: Microsoft Equation 3.0 >> and << OLE Object: Microsoft Equation 3.0 >> for different types of aerosol. We use the aerosol and radiative properties obtained during the Atmospheric Science Program (ARM) Aerosol Intensive Operational Period (IOP) to validate our retrieval in two ways. First, the MFRSR-retrieved optical properties are compared with those obtained from independent surface, Aerosol Robotic Network (AERONET) and aircraft measurements. The MFRSR-retrieved optical properties are in reasonable agreement with these independent measurements. Second, we perform radiative closure experiments using the MFRSR-retrieved optical properties. The calculated broadband values of the direct and diffuse fluxes are comparable (~ 5 << OLE Object: Microsoft Equation 3.0 >> ) to those obtained from measurements.

  7. aerosol characterization system: Topics by E-print Network

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

    soluble in water: 2. Isolation of acid, neutral, and basic fractions by modified size Weber, Rodney 4 Desert dust aerosol age characterized by massage tracking of tracers...

  8. Climate response of the South Asian monsoon system to anthropogenic aerosols

    SciTech Connect (OSTI)

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

    2012-07-13T23:59:59.000Z

    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.

  9. Droplet activation properties of organic aerosols observed at an urban site during CalNex-LA

    E-Print Network [OSTI]

    Homes, Christopher C.

    directly influence the global energy budget, by scattering and absorbing incoming solar radiation [Jacobson. This effect is known as the first indirect aerosol effect or Twomey effect [Twomey, 1977]. The smaller cloud to an increase in cloud lifetime and coverage (the second indirect aerosol effect) [Albrecht, 1989]. Although

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

    SciTech Connect (OSTI)

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

    2012-09-25T23:59:59.000Z

    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 25°N. Our results also show an east-west asymmetry in the fast responses to anthropogenic aerosols causing increases in precipitation west of 80°E but decreases east of it.

  11. Fission-product aerosol sampling system for LWR experiments in the TREAT reactor

    SciTech Connect (OSTI)

    Dunn, P.F.

    1983-01-01T23:59:59.000Z

    This work summarizes the design and collection characteristics of a fission-product aerosol sampling system that was developed for a series of light water reactor (LWR) source-term experiments under consideration for performance in 1984 at Argonne National Laboratory's TREAT reactor. These tests would be performed using a bundle of four preirradiated, Zircaloy-clad LWR fuel pins. In these tests, fuel pin integrity would be breached under various simulated accident conditions. The aerosol sampling system was designed to efficiently extract and collect these aerosols such that time-averaged aerosol size distributions, number concentrations and mass loadings could be determined accurately for each experiment, using a combination of real-time and time-interval measurements and post-test analytical techniques. The entire system also was designed to be disassembled remotely because of potentially high levels of radioactivity.

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

    SciTech Connect (OSTI)

    Sengupta, M.; Wagner, M. J.

    2011-08-01T23:59:59.000Z

    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.

  13. Real-Time Detection Method And System For Identifying Individual Aerosol Particles

    DOE Patents [OSTI]

    Gard, Eric Evan (San Francisco, CA); Fergenson, David Philip (Livermore, CA)

    2005-10-25T23:59:59.000Z

    A method and system of identifying individual aerosol particles in real time. Sample aerosol particles are compared against and identified with substantially matching known particle types by producing positive and negative test spectra of an individual aerosol particle using a bipolar single particle mass spectrometer. Each test spectrum is compared to spectra of the same respective polarity in a database of predetermined positive and negative spectra for known particle types and a set of substantially matching spectra is obtained. Finally the identity of the individual aerosol particle is determined from the set of substantially matching spectra by determining a best matching one of the known particle types having both a substantially matching positive spectrum and a substantially matching negative spectrum associated with the best matching known particle type.

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

    E-Print Network [OSTI]

    Siegel, Jeffrey

    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

  15. AERONET: The Aerosol Robotic Network

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

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

  16. Aerosol Optical Depth Prediction from Satellite Observations by Multiple Instance Regression

    E-Print Network [OSTI]

    Vucetic, Slobodan

    airborne particles that both reflect and absorb incoming solar radiation and whose effect on the Earth's radiation budget is one of the biggest challenges of current climate research. To help address profiles, cloud/aerosol properties, or vegetation cover. Achieving accurate estimations is a critical

  17. Real-time detection method and system for identifying individual aerosol particles

    DOE Patents [OSTI]

    Gard, Eric E. (San Francisco, CA); Coffee, Keith R. (Patterson, CA); Frank, Matthias (Oakland, CA); Tobias, Herbert J. (Kensington, CA); Fergenson, David P. (Alamo, CA); Madden, Norm (Livermore, CA); Riot, Vincent J. (Berkeley, CA); Steele, Paul T. (Livermore, CA); Woods, Bruce W. (Livermore, CA)

    2007-08-21T23:59:59.000Z

    An improved method and system of identifying individual aerosol particles in real time. Sample aerosol particles are collimated, tracked, and screened to determine which ones qualify for mass spectrometric analysis based on predetermined qualification or selection criteria. Screening techniques include one or more of determining particle size, shape, symmetry, and fluorescence. Only qualifying particles passing all screening criteria are subject to desorption/ionization and single particle mass spectrometry to produce corresponding test spectra, which is used to determine the identities of each of the qualifying aerosol particles by comparing the test spectra against predetermined spectra for known particle types. In this manner, activation cycling of a particle ablation laser of a single particle mass spectrometer is reduced.

  18. Droplet Activation Properties of Organic Aerosols Observed at an Urban Site during CalNex-LA

    SciTech Connect (OSTI)

    Mei, Fan; Hayes, Patrick L.; Ortega, Amber; Taylor, Jonathan W.; Allan, James D.; Gilman, Jessica; Kuster, W. C.; de Gouw, Joost A.; Jimenez, Jose L.; Wang, Jian

    2013-04-11T23:59:59.000Z

    Size-resolved cloud condensation nuclei (CCN) spectra and aerosol chemical composition were characterized at an urban supersite in Pasadena, California from 15 May to 4 June, 2010, during the CalNex campaign. The derived hygroscopicity (?CCN) of CCN-active particles with diameter between 97 and 165 nm ranged from 0.05 to 0.4. Diurnal variation showed a slight decrease of ?CCN from 8:00 to 16:00 (from 0.24 to 0.20), which is attributed to increasing organics volume fraction resulted from secondary organic aerosol (SOA) formation. The derived hygroscopicity distribution and maximum activated fraction of the size selected particles were examined as functions of photochemical age. The result indicates that condensation of secondary species (e.g., SOA and sulfate) quickly converted hydrophobic particles to hydrophilic ones, and during daytime, nearly every particle became a CCN at ~0.4% in just a few hours. Based on ?CCN and aerosol chemical composition, the organic hygroscopicity (?org) was derived, and ranged from 0.05 to 0.23 with an average value of 0.13, consistent with the results from earlier studies. The derived ?org generally increased with the organic oxidation level, and most of the variation in ?org could be explained by the variation of the organic O:C atomic ratio alone. The least squares fit of the data yielded ?org =(0.83±0.06) ? (O:C) +(-0.19±0.02). Compared to previous results based on CCN measurements of laboratory generated aerosols, ?org derived from measurements during the CalNex campaign exhibited stronger increase with O:C atomic ratio, and therefore substantially higher values for organics with average O:C greater than 0.5.

  19. Southern hemisphere tropospheric aerosol backscatter measurements - Implications for a laser wind system

    SciTech Connect (OSTI)

    Gras, J.L.; Platt, C.M.R.; Young, S.A.; Banks, S.M. (Commonwealth Scientific and Industrial Research Organization, Aspendale (Australia)); Jones, W.D. (NASA Marshall Space Flight Center, Huntsville, AL (USA)); Huffaker, R.M. (Coherent Technologies Inc., Boulder, CO (USA)); Booth, D.J. (Dept. of Applied Physics, Footscray (Australia))

    1991-03-20T23:59:59.000Z

    Values of backscatter coefficient at 0.532 {mu}m, 0.694 {mu}m, and 10.6 {mu}m were determined both by direct measurement and by Mie computation from measured aerosol microphysical properties in the eastern Australian region from 4{degree}S to 41{degree}S. Volume backscatter coefficients at 10.6 {mu}m were typically in the range 1 {times} 10{sup {minus}11} to 3 {times} 10{sup {minus}11} m{sup {minus}1}sr{sup {minus}1} for both approaches, although the experimental uncertainty in both cases was quite large. Agreement between the shorter wavelength lidars and the aerosol data was typically within the combined experimental uncertainties, although direct measurements were systematically larger than values derived from the aerosol data; individual regions were observed where the disagreement was larger than the combined error. Backscatter at 10.6 {mu}m and at visible wavelengths was found to be sensitive to essentially different regions of the aerosol size spectrum, questioning to some degree the validity of using short-wavelength extinction and backscatter data to infer tha global distribution of backscatter at wavelengths around 10.6 {mu}m. Considerable day-to-day variability in backscatter was observed at all wavelengths. The implications of the very low backscatter values found, compared to northern hemisphere values, should be considered in the design of the Laser Atmospheric Wind Sounder (LAWS).

  20. NUCLEAR NON-PROLIFERATION-TASK 1: Deployable Plume and Aerosol Release Prediction and Tracking System

    SciTech Connect (OSTI)

    John Kleppe, Ph.D., William Norris, Ph.D., Mehdi Etezada, Ph.D., P.E.

    2006-07-19T23:59:59.000Z

    This contract was awarded in response to a proposal in which a deployable plume and aerosol release prediction and tracking system would be designed, fabricated, and tested. The system would gather real time atmospheric data and input it into a real time atmospheric model that could be used for plume predition and tracking. The system would be able to be quickly deployed by aircraft to points of interest or positioned for deployment by vehicles. The system would provide three dimensional (u, v, and w) wind vector data, inversion height measurements, surface wind information, classical weather station data, and solar radiation. The on-board real time computer model would provide the prediction of the behavior of plumes and released aerosols.

  1. Aerosol–climate interactions in the Norwegian Earth System Model – NorESM1-M

    SciTech Connect (OSTI)

    Kirkevag, A.; Iversen, T.; Seland, O.; Hoose, C.; Kristjansson, J. E.; Struthers, H.; Ekman, A. M.; Ghan, Steven J.; Griesfeller, Jan; Nilsson, E. D.; Schulz, M.

    2013-02-08T23:59:59.000Z

    The objective of this study is to document and evaluate recent changes and updates to the module for aerosols and aerosol–cloud–radiation interactions in the atmospheric module CAM4-Oslo of the core version of the Norwegian Earth System Model (NorESM), NorESM1-M. Particular attention is paid to the role of natural organics, sea salt, and mineral dust in determining the gross aerosol properties as well as the anthropogenic contribution to these properties and the associated direct and indirect radiative forcing. The aerosol module is extended from earlier versions that have been published, and includes life-cycling of sea salt, mineral dust, particulate sulphate, black carbon, and primary and secondary organics. The impacts of most of the numerous changes since previous versions are thoroughly explored by sensitivity experiments. The most important changes are: modified prognostic sea salt emissions; updated treatment of precipitation scavenging and gravitational settling; inclusion of biogenic primary organics and methane sulphonic acid (MSA) from oceans; almost doubled production of land-based biogenic secondary organic aerosols (SOA); and increased ratio of organic matter to organic carbon (OM/OC) for biomass burning aerosols from 1.4 to 2.6. Compared with in situ measurements and remotely sensed data, the new treatments of sea salt and dust aerosols give smaller biases in near-surface mass concentrations and aerosol optical depth than in the earlier model version. The model biases for mass concentrations are approximately unchanged for sulphate and BC. The enhanced levels of modeled OM yield improved overall statistics, even though OM is still underestimated in Europe and overestimated in North America. The global anthropogenic aerosol direct radiative forcing (DRF) at the top of the atmosphere has changed from a small positive value to ?0.08 W m?2 in CAM4-Oslo. The sensitivity tests suggest that this change can be attributed to the new treatment of biomass burning aerosols and gravitational settling. Although it has not been a goal in this study, the new DRF estimate is closer both to the median model estimate from the AeroCom intercomparison and the best estimate in IPCC AR4. Estimated DRF at the ground surface has increased by ca. 60%, to ?1.89 W m?2. We show that this can be explained by new emission data and omitted mixing of constituents between updrafts and downdrafts in convective clouds. The increased abundance of natural OM and the introduction of a cloud droplet spectral dispersion formulation are the most important contributions to a considerably decreased estimate of the indirect radiative forcing (IndRF). The IndRF is also found to be sensitive to assumptions about the coating of insoluble aerosols by sulphate and OM. The IndRF of ?1.2 W m?2, which is closer to the IPCC AR4 estimates than the previous estimate of ?1.9 W m?2, has thus been obtained without imposing unrealistic artificial lower bounds on cloud droplet number concentrations.

  2. Multicomponent aerosol dynamic of the Pb-O[sub 2] system in a bench scale flame incinerator

    SciTech Connect (OSTI)

    Lin, W.Y.; Sethi, V.; Biswas, P.

    1992-01-01T23:59:59.000Z

    The article gives results of a study to understand the formation and growth of lead particles in a flame incinerator. A bench scale flame incinerator was used to perform controlled experiments with lead acetate as a test compound. A dilution probe (in conjunction with real-time aerosol instruments) was used to measure the evolution of the particle size distribution at different locations in the flame region. A multicomponent lognormal aerosol model was developed accounting for the chemistry of the lead-oxygen system, and for such aerosol dynamic phenomena as nucleation, coagulation, and condensation. Reasonable agreement was obtained between the predictions of the model using appropriate kinetic parameters and the experimental results.

  3. A COMPARISON OF SURFACE OBSERVATIONS AND ECHAM4-GCM EXPERIMENTS AND ITS RELEVANCE TO THE INDIRECT AEROSOL EFFECT

    E-Print Network [OSTI]

    of the indirect aerosol effect. The modeled annual cloud cover and solar radiation cycles for the present day at the surface, total cloud cover and precipitation rates have been used to evaluate aerosol. The model correctly predicts the annual mean total cloud cover in Germany and the US, whereas global solar

  4. aerosol prediction systems: Topics by E-print Network

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

    The aim of the control design is to guarantee that the oxygen to be applied to the air compressor. An admissible robust control invariant set for the PWA model of the system...

  5. Methodology to quantify leaks in aerosol sampling system components 

    E-Print Network [OSTI]

    Vijayaraghavan, Vishnu Karthik

    2004-11-15T23:59:59.000Z

    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...

  6. aerosol delivery systems: Topics by E-print Network

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

    at The Second Science Team Meeting of the Atmospheric System Research (ASR) Program, San Antonio First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22...

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

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

    The Aerosol Characterization Experiments (ACE) were designed to increase understanding of how atmospheric aerosol particles affect the Earth's climate system. These experiments integrated in-situ measurements, satellite observations, and models to reduce the uncertainty in calculations of the climate forcing due to aerosol particles and improve the ability of models to predict the influences of aerosols on the Earth's radiation balance. ACE-Asia was the fourth in a series of experiments organized by the International Global Atmospheric Chemistry (IGAC) Program (A Core Project of the International Geosphere Biosphere Program). The Intensive Field Phase for ACE-Asia took place during the spring of 2001 (mid-March through early May) off the coast of China, Japan and Korea. ACE-Asia pursued three specific objectives: 1) Determine the physical, chemical, and radiative properties of the major aerosol types in the Eastern Asia and Northwest Pacific region and investigate the relationships among these properties. 2) Quantify the physical and chemical processes controlling the evolution of the major aerosol types and in particular their physical, chemical, and radiative properties. 3) Develop procedures to extrapolate aerosol properties and processes from local to regional and global scales, and assess the regional direct and indirect radiative forcing by aerosols in the Eastern Asia and Northwest Pacific region [Edited and shortened version of summary at http://data.eol.ucar.edu/codiac/projs?ACE-ASIA]. The Ace-Asia collection contains 174 datasets.

  8. High Flash-point Fluid Flow System Aerosol Flammability Study and Combustion Mechanism Analysis

    E-Print Network [OSTI]

    Huang, Szu-Ying

    2013-12-02T23:59:59.000Z

    The existence of flammable aerosols creates fire and explosion hazards in the process industry. Due to the operation condition of high pressure circumstances, heat transfer fluids tend to form aerosols when accidental leaking occurs on pipelines...

  9. Reply to Comments on "Elevated Heat Pump" Hypothesis for the1 AerosolMonsoon Hydroclimate Link: "Grounded" in Observations?2

    E-Print Network [OSTI]

    Nigam, Sumant

    1 Reply to Comments on "Elevated Heat Pump" Hypothesis for the1 Aerosol­Monsoon Hydroclimate Link, hereafter LK11] defense of the Elevated Heat Pump (EHP) hypothesis35 is unsubstantiated. Nigam and Bollasina

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

    SciTech Connect (OSTI)

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

    2013-11-12T23:59:59.000Z

    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.

  11. Description and Evaluation of Tropospheric Chemistry and Aerosols in the Community Earth System Model (CESM1.2)

    SciTech Connect (OSTI)

    Tilmes, S.; Lamarque, J.-F.; Emmons, L.; Kinnison, Douglas E.; Ma, Po-Lun; Liu, Xiaohong; Ghan, Steven J.; Bardeen, C.; Arnold, S.; Deeter, M.; Vitt, Francis; Ryerson, T. B.; Elkins, J. W.; Moore, F.; Spackman, R.; Martin, M. V.

    2015-01-01T23:59:59.000Z

    The Community Atmosphere Model (CAM), version 5, is now coupled to extensive tropospheric and stratospheric chemistry, called CAM5-chem, and is available in addition to CAM4-chem in the Community Earth System Model (CESM) version 1.2. Both configurations are well suited as tools for atmospheric-chemistry modeling studies in the troposphere and lower stratosphere, whether with internally derived “free running” (FR) meteorology, or “specified dynamics” (SD). The main focus of this paper is to compare the performance of these configurations against observations from surface, aircraft, and satellite, as well as understand the origin of the identified differences. We particularly focus on comparing present-day methane lifetime estimates within the different model configurations, which range between 7.8 years in the SD configuration of CAM5-chem and 8.8 years in the FR configuration of CAM4-chem. We find that tropospheric surface area density is an important factor in controlling the burden of the hydroxyl radical (OH), which causes differences in tropical methane lifetime of about half a year between CAM4-chem and CAM5-chem. In addition, different distributions of nitrogen oxides (NOx) produced from lightning production explain about half of the difference between SD and FR model versions in both CAM4-chem and CAM5-chem. Remaining differences in the tropical OH burden are due to enhanced tropical ozone burden in SD configurations compared to the FR versions, which are not only caused by differences in chemical production or loss, but also by transport and mixing. For future studies, we recommend the use of CAM5-chem, due to improved aerosol description and inclusion of aerosol-cloud interactions. However, smaller tropospheric surface area density in the current version of CAM5-chem compared to CAM4-chem results in larger oxidizing capacity in the troposphere and therefore a shorter methane lifetime.

  12. SEU induced errors observed in microprocessor systems

    SciTech Connect (OSTI)

    Asenek, V.; Underwood, C.; Oldfield, M. [Univ. of Surrey, Guildford (United Kingdom). Surrey Space Centre] [Univ. of Surrey, Guildford (United Kingdom). Surrey Space Centre; Velazco, R.; Rezgui, S.; Cheynet, P. [TIMA Lab., Grenoble (France)] [TIMA Lab., Grenoble (France); Ecoffet, R. [Centre National d`Etudes Spatiales, Toulouse (France)] [Centre National d`Etudes Spatiales, Toulouse (France)

    1998-12-01T23:59:59.000Z

    In this paper, the authors present software tools for predicting the rate and nature of observable SEU induced errors in microprocessor systems. These tools are built around a commercial microprocessor simulator and are used to analyze real satellite application systems. Results obtained from simulating the nature of SEU induced errors are shown to correlate with ground-based radiation test data.

  13. Characterizing the Vertical Distribution of Aerosols Over the ARM SGP Site

    SciTech Connect (OSTI)

    Richard Ferrare, Connor Flynn, David Turner

    2009-05-05T23:59:59.000Z

    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

  14. The Two-Column Aerosol Project (TCAP) Science Plan

    SciTech Connect (OSTI)

    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

    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.

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

    SciTech Connect (OSTI)

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

    2011-07-19T23:59:59.000Z

    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.

  16. Multi-year observations of the tropical Atlantic atmosphere: Multidisciplinary applications of the NOAA Aerosols and Ocean

    E-Print Network [OSTI]

    of the NOAA Aerosols and Ocean Science Expeditions (AEROSE) Nicholas R. Nalli Dell Services, Federal Science Expedition (AEROSE) field campaigns. Following the original 2004 campaign onboard the Ronald H. Brown, AEROSE has operated on a yearly basis since 2006 in collaboration with the NOAA Prediction

  17. Surface Meteorological Observation System (SMOS) Handbook

    SciTech Connect (OSTI)

    Ritsche, MT

    2008-03-01T23:59:59.000Z

    The Surface Meteorological Observation System (SMOS) mostly uses conventional in situ sensors to obtain 1-minute, 30-minute, and 1440-minute (daily) averages of surface wind speed, wind direction, air temperature, relative humidity (RH), barometric pressure, and precipitation at the Central Facility and many of the extended facilities of the Southern Great Plains (SGP) climate research site. The SMOSs are not calibrated as systems. The sensors and the data logger (which includes the analog-to-digital converter, or A/D) are calibrated separately. All systems are installed using components that have a current calibration. SMOSs have not been installed at extended facilities located within about 10 km of existing surface meteorological stations, such as those of the Oklahoma Mesonet. The Surface Meteorological Observation Systems are used to create climatology for each particular location, and to verify the output of numerical weather forecast and other model output. They are also used to “ground-truth” other remote sensing equipment.

  18. The web-PLOP observation prioritisation system

    E-Print Network [OSTI]

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

    2008-05-14T23:59:59.000Z

    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/

  19. Mass spectrometric approaches for chemical characterisation of atmospheric aerosols: critical

    E-Print Network [OSTI]

    Nizkorodov, Sergey

    Mass spectrometric approaches for chemical characterisation of atmospheric aerosols: critical. Atmospheric aerosols have profound effects on the environment through several physicochemical processes on the respiratory and cardiovascular systems. Understanding aerosol atmospheric chemistry and its environmental

  20. Aerosol engineering: design and stability of aerosol reactors

    SciTech Connect (OSTI)

    Pratsinis, S.E.

    1985-01-01T23:59:59.000Z

    A theoretical study of the performance of aerosol reactors is presented. The goals of this study are (1) to identify the appropriate reactor types (batch, CSTR, and tubular) for production of aerosol with specific properties (for example, uniform size particles, high aerosol surface area, etc.) and (2) to investigate the effect of various process parameters on product aerosol characteristics and on the stability of operation of aerosol reactors. In all the reactors considered, the aerosol dynamics were detemined by chemical reaction, nucleation, and aerosol growth in the free molecule regime in the absence of coagulation at isothermal conditions. Formulation of the aerosol dynamics in terms of moments of the aerosol size distribution facilitated the numerical solution of the resulting systems of ordinary or partial differential equations. The stability characteristics of a continuous stirred tank aerosol reactor (CSTAR) were investigated since experimental data in the literature indicate that under certain conditions this reactor exhibits oscillatory behavior with respect to product aerosol concentration and size distribution.

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

    SciTech Connect (OSTI)

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

    2007-11-01T23:59:59.000Z

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

  2. Optimization of aerosol penetration through transport lines

    E-Print Network [OSTI]

    Wong Luque, Fermin Samuel

    1992-01-01T23:59:59.000Z

    function of Reynolds number for the aerosol transport system of Strom. Tube diameter = 15. 9 mm. 69 Figure Page 16. Comparison of model, experiments and Strom's data for aerosol penetration through the transport system of Strom. Tube diameter = 15. 9... mm, AED = 8 nm. 70 17. Comparison of model and experiments for aerosol penetration through the transport system of Strom. Tube diameter = 15. 9 mm, AED = 10 pm. . 71 18. Comparison of model, experiments and Strom's data for aerosol penetration...

  3. Common Cyber Security Vulnerabilities Observed in Control System...

    Energy Savers [EERE]

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

  4. Modal aerosol dynamics modeling

    SciTech Connect (OSTI)

    Whitby, E.R.; McMurry, P.H.; Shankar, U.; Binkowski, F.S.

    1991-02-01T23:59:59.000Z

    The report presents the governing equations for representing aerosol dynamics, based on several different representations of the aerosol size distribution. Analytical and numerical solution techniques for these governing equations are also reviewed. Described in detail is a computationally efficient numerical technique for simulating aerosol behavior in systems undergoing simultaneous heat transfer, fluid flow, and mass transfer in and between the gas and condensed phases. The technique belongs to a general class of models known as modal aerosol dynamics (MAD) models. These models solve for the temporal and spatial evolution of the particle size distribution function. Computational efficiency is achieved by representing the complete aerosol population as a sum of additive overlapping populations (modes), and solving for the time rate of change of integral moments of each mode. Applications of MAD models for simulating aerosol dynamics in continuous stirred tank aerosol reactors and flow aerosol reactors are provided. For the application to flow aerosol reactors, the discussion is developed in terms of considerations for merging a MAD model with the SIMPLER routine described by Patankar (1980). Considerations for incorporating a MAD model into the U.S. Environmental Protection Agency's Regional Particulate Model are also described. Numerical and analytical techniques for evaluating the size-space integrals of the modal dynamics equations (MDEs) are described. For multimodal logonormal distributions, an analytical expression for the coagulation integrals of the MDEs, applicable for all size regimes, is derived, and is within 20% of accurate numerical evaluation of the same moment coagulation integrals. A computationally efficient integration technique, based on Gauss-Hermite numerical integration, is also derived.

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

    SciTech Connect (OSTI)

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

    2011-04-01T23:59:59.000Z

    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.

  6. ATI TDA 5A aerosol generator evaluation

    SciTech Connect (OSTI)

    Gilles, D.A.

    1998-07-27T23:59:59.000Z

    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.

  7. Sensitivity of Remote Aerosol Distributions to Representation of Cloud-Aerosol Interactions in a Global Climate Model

    SciTech Connect (OSTI)

    Wang, Hailong; Easter, Richard C.; Rasch, Philip J.; Wang, Minghuai; Liu, Xiaohong; Ghan, Steven J.; Qian, Yun; Yoon, Jin-Ho; Ma, Po-Lun; Vinoj, V.

    2013-06-05T23:59:59.000Z

    Many global aerosol and climate models, including the widely used Community Atmosphere Model version 5 (CAM5), have large biases in predicting aerosols in remote regions such as upper troposphere and high latitudes. In this study, we conduct CAM5 sensitivity simulations to understand the role of key processes associated with aerosol transformation and wet removal affecting the vertical and horizontal long-range transport of aerosols to the remote regions. Improvements are made to processes that are currently not well represented in CAM5, which are guided by surface and aircraft measurements together with results from a multi-scale aerosol-climate model (PNNL-MMF) that explicitly represents convection and aerosol-cloud interactions at cloud-resolving scales. We pay particular attention to black carbon (BC) due to its importance in the Earth system and the availability of measurements. We introduce into CAM5 a new unified scheme for convective transport and aerosol wet removal with explicit aerosol activation above convective cloud base. This new implementation reduces the excessive BC aloft to better simulate observed BC profiles that show decreasing mixing ratios in the mid- to upper-troposphere. After implementing this new unified convective scheme, we examine wet removal of submicron aerosols that occurs primarily through cloud processes. The wet removal depends strongly on the sub-grid scale liquid cloud fraction and the rate of conversion of liquid water to precipitation. These processes lead to very strong wet removal of BC and other aerosols over mid- to high latitudes during winter months. With our improvements, the Arctic BC burden has a10-fold (5-fold) increase in the winter (summer) months, resulting in a much better simulation of the BC seasonal cycle as well. Arctic sulphate and other aerosol species also increase but to a lesser extent. An explicit treatment of BC aging with slower aging assumptions produces an additional 30-fold (5-fold) increase in the Arctic winter (summer) BC burden. This BC aging treatment, however, has minimal effect on other under-predicted species. Interestingly, our modifications to CAM5 that aim at improving prediction of high-latitude and upper tropospheric aerosols also produce much better AOD and AAOD over various other regions globally when compared to multi-year AERONET retrievals. The improved aerosol distributions have impacts on other aspects of CAM5, improving the simulation of global mean liquid water path and cloud forcing.

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

    SciTech Connect (OSTI)

    Heitkamp, M

    2006-08-07T23:59:59.000Z

    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.

  9. Atmospheric Aerosols Workshop | EMSL

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

    Atmospheric Aerosols Workshop Atmospheric Aerosols Workshop EMSL Science Theme Advisory Panel Workshop - Atmospheric Aerosol Chemistry, Climate Change, and Air Quality. Baer DR, BJ...

  10. Aerosol Properties and Radiative Forcing over Kanpur during Severe Aerosol Loading Conditions

    SciTech Connect (OSTI)

    Kaskaoutis, D. G.; Sinha, P. R.; Vinoj, V.; Kosmopoulos, P. G.; Tripathi, S. N.; Misra, Amit; Sharma, M.; Singh, R. P.

    2013-11-01T23:59:59.000Z

    Atmospheric aerosols over India exhibit large spatio-temporal fluctuation driven by the local monsoon system, emission rates and seasonally-changed air masses. The northern part of India is well-known for its high aerosol loading throughout the year due to anthropogenic emissions, dust influence and biomass burning. On certain circumstances and, under favorable weather conditions, the aerosol load can be severe, causing significant health concerns and climate implications. The present work analyzes the aerosol episode (AE) days and examines the modification in aerosol properties and radiative forcing during the period 2001-2010 based on Kanpur-AERONET sun photometer data. As AEs are considered the days having daily-mean aerosol optical depth (AOD) above the decadal mean + 1 STD (standard deviation); the threshold value is defined at 0.928. The results identify 277 out of 2095 days (13.2%) of AEs over Kanpur, which are most frequently observed during post-monsoon (78 cases, 18.6%) and monsoon (76, 14.7%) seasons due to biomass-burning episodes and dust influence, respectively. On the other hand, the AEs in winter and pre-monsoon are lower in both absolute and percentage values (65, 12.5% and 58, 9.1%, respectively). The modification in aerosol properties on the AE days is strongly related to season. Thus, in post-monsoon and winter the AEs are associated with enhanced presence of fine-mode aerosols and Black Carbon from anthropogenic pollution and any kind of burning, while in pre-monsoon and monsoon seasons they are mostly associated with transported dust. Aerosol radiative forcing (ARF) calculated using SBDART shows much more surface (~-69 to -97 Wm-2) and Top of Atmosphere cooling (-20 to -30 Wm-2) as well as atmospheric heating (~43 to 71 Wm-2) during the AE days compared to seasonal means. These forcing values are mainly controlled by the higher AODs and the modified aerosol characteristics (Angstrom ?, SSA) during the AE days in each season and may cause severe climate implications over Ganges Basin with further consequences on atmospheric heating, cloud microphysics, monsoon rainfall and melting of Himalayan glaciers.

  11. 6, 75197562, 2006 Simulating aerosol

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    , particle number concentration and aerosol size-distribution. The model takes into account sulfate (SO4. This model system enables explicit simulations of the particle number concentration and size-distribution of aerosol dynamical processes (nucleation, condensation, coagulation) is evaluated by comparison

  12. 6, 55435583, 2006 Aerosol nucleation

    E-Print Network [OSTI]

    Boyer, Edmond

    and cloud cover via the second indirect aerosol effect that would explain observed variations in global cloud cover. We esti- mate that the variation in radiative forcing resulting from a response of clouds

  13. Microphysical Effects Determine Macrophysical Response for Aerosol Impacts on Deep Convective Clouds

    SciTech Connect (OSTI)

    Fan, Jiwen; Leung, Lai-Yung R.; Rosenfeld, Daniel; Chen, Qian; Li, Zhanqing; Zhang, Jinqiang; Yan, Hongru

    2013-11-26T23:59:59.000Z

    Deep convective clouds (DCCs) play a crucial role in the general circulation and energy and hydrological cycle of our climate system. Anthropogenic and natural aerosol particles can influence DCCs through changes in cloud properties, precipitation regimes, and radiation balance. Modeling studies have reported both invigoration and suppression of DCCs by aerosols, but none has fully quantified aerosol impacts on convection life cycle and radiative forcing. By conducting multiple month-long cloud-resolving simulations with spectral-bin cloud microphysics that capture the observed macro- and micro-physical properties of summer convective clouds in the tropics and mid-latitudes, this study provides the first comprehensive look at how aerosols affect cloud cover, cloud top height (CTH), and radiative forcing. Observations validate these simulation results. We find that microphysical aerosol effects contribute predominantly to increased cloud cover and CTH by inducing larger amount of smaller but longer lasting ice particles in the stratiform/anvils of DCCs with dynamical aerosol effects contributing at most ~ 1/4 of the total increase of cloud cover. The overall effect is a radiative warming in the atmosphere (3 to 5 W m-2) with strong surface cooling (-5 to -8 W m-2). Herein we clearly identified mechanisms more important than and additional to the invigoration effects hypothesized previously that explain the consistent signatures of increased cloud tops area and height by aerosols in DCCs revealed by observations.

  14. Modeling of metallic aerosol formation in a multicomponent system at high temperatures using a discrete-sectional model. Appendix 7

    SciTech Connect (OSTI)

    NONE

    1997-02-01T23:59:59.000Z

    A multicomponent discrete-sectional model was used to simulate the fate of lead in a high temperature system. The results show the ability of the developed model to simulate metallic aerosol systems at high temperatures. The PbO reaction and nucleation rate can be determined by comparing the simulations and the experimental data. Condensation on SiO{sub 2} particle surfaces is found important for removing the PbO vapor. The value of the accommodation factor that is applied to account for nonidealities in the condensation process are determined. The differences between the nanosized particles and the bulk particles are elucidated. The use of such a model helped to understand the effects of various mechanisms in determining the metal oxide vapor concentration profile and in establishing the ultimate particle size distribution.

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

    SciTech Connect (OSTI)

    Sexton, L.

    2012-06-06T23:59:59.000Z

    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).

  16. Aerosol Observing Systems (AOS), New Capabilities for ASR Researchers Stephen R. Springston (srs@bnl.gov)

    E-Print Network [OSTI]

    of remote access over the internet allows mentors complete control over AOS infrastructure components to erect railing, sampling mast and instrument turn on) o Tolerance for heat/cold, wind o `Turtle' mode/off all subsystems allowing both remote and autonomous restart and shutdown of unit in graded steps o

  17. DE/SC-ARM/TR-130 Aerosol Observing System Cloud Condensation Nuclei Average

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville Power Administration would

  18. Aerosol Cans? -Aerosol cans use a pressurized

    E-Print Network [OSTI]

    Jia, Songtao

    WHAT TO DO WITH... Aerosol Cans? -Aerosol cans use a pressurized propellant to distribute the product. Propellants are often flammable and/or toxic. Therefore, never store aerosol cans near ignition aerosol cans must be disposed of as hazardous waste. PROPER SAFETY EQUIPMENT Safety Glasses - Proper eye

  19. aerosol deposition method: Topics by E-print Network

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

    and remotely sensed aerosol observations. William D. Collins; Phillip J. Rasch; Brian E. Eaton; Boris V. Khattatov; Jean-francois Lamarque; C. Zender 2001-01-01 43 Ambient aerosol...

  20. Chapter 3: Evaluating the impacts of carbonaceous aerosols on clouds and climate

    SciTech Connect (OSTI)

    Menon, Surabi; Del Genio, Anthony D.

    2007-09-03T23:59:59.000Z

    Any attempt to reconcile observed surface temperature changes within the last 150 years to changes simulated by climate models that include various atmospheric forcings is sensitive to the changes attributed to aerosols and aerosol-cloud-climate interactions, which are the main contributors that may well balance the positive forcings associated with greenhouse gases, absorbing aerosols, ozone related changes, etc. These aerosol effects on climate, from various modeling studies discussed in Menon (2004), range from +0.8 to -2.4 W m{sup -2}, with an implied value of -1.0 W m{sup -2} (range from -0.5 to -4.5 W m{sup -2}) for the aerosol indirect effects. Quantifying the contribution of aerosols and aerosol-cloud interactions remain complicated for several reasons some of which are related to aerosol distributions and some to the processes used to represent their effects on clouds. Aerosol effects on low lying marine stratocumulus clouds that cover much of the Earth's surface (about 70%) have been the focus of most of prior aerosol-cloud interaction effect simulations. Since cumulus clouds (shallow and deep convective) are short lived and cover about 15 to 20% of the Earth's surface, they are not usually considered as radiatively important. However, the large amount of latent heat released from convective towers, and corresponding changes in precipitation, especially in biomass regions due to convective heating effects (Graf et al. 2004), suggest that these cloud systems and aerosol effects on them, must be examined more closely. The radiative heating effects for mature deep convective systems can account for 10-30% of maximum latent heating effects and thus cannot be ignored (Jensen and Del Genio 2003). The first study that isolated the sensitivity of cumulus clouds to aerosols was from Nober et al. (2003) who found a reduction in precipitation in biomass burning regions and shifts in circulation patterns. Aerosol effects on convection have been included in other models as well (cf. Jacobson, 2002) but the relative impacts on convective and stratiform processes were not separated. Other changes to atmospheric stability and thermodynamical quantities due to aerosol absorption are also known to be important in modifying cloud macro/micro properties. Linkages between convection and boreal biomass burning can also impact the upper troposphere and lower stratosphere, radiation and cloud microphysical properties via transport of tropospheric aerosols to the lower stratosphere during extreme convection (Fromm and Servranckx 2003). Relevant questions regarding the impact of biomass aerosols on convective cloud properties include the effects of vertical transport of aerosols, spatial and temporal distribution of rainfall, vertical shift in latent heat release, phase shift of precipitation, circulation and their impacts on radiation. Over land surfaces, a decrease in surface shortwave radiation ({approx} 3-6 W m{sup -2} per decade) has been observed between 1960 to 1990, whereas, increases of 0.4 K in land temperature during the same period that occurred have resulted in speculations that evaporation and precipitation should also have decreased (Wild et al. 2004). However, precipitation records for the same period over land do not indicate any significant trend (Beck et al. 2005). The changes in precipitation are thought to be related to increased moisture advection from the oceans (Wild et al. 2004), which may well have some contributions from aerosol-radiation-convection coupling that could modify circulation patterns and hence moisture advection in specific regions. Other important aspects of aerosol effects, besides the direct, semi-direct, microphysical and thermodynamical impacts include alteration of surface albedos, especially snow and ice covered surfaces, due to absorbing aerosols. These effects are uncertain (Jacobson, 2004) but may produce as much as 0.3 W m{sup -2} forcing in the Northern hemisphere that could contribute to melting of ice and permafrost and change in the length of the season (e.g. early arrival of Spring

  1. The Observers' Paradox: Apparent Computational Complexity in Physical Systems

    E-Print Network [OSTI]

    Pollack, Jordan B.

    The Observers' Paradox: Apparent Computational Complexity in Physical Systems John F. Kolen Research Department of Computer and Information Sciences The Ohio State University Columbus, OH 43210 kolen

  2. Navigation System for Ground Vehicles using Temporally Interconnected Observers

    E-Print Network [OSTI]

    navigation technique for an automotive vehicle. This method involves several observers, each designed for a particular type of trajectory, that are turned on and off according to a switching policy. Each observer of observer design of vehicular systems. A typical example of such practices1 is found in the navigation

  3. Version 3.0 Earth Observing System (EOS)

    E-Print Network [OSTI]

    Waliser, Duane E.

    D-33192 Version 3.0 Earth Observing System (EOS) Tropospheric Emission Spectrometer (TES) Data_04 Data November 5, 2007 Version 3.0 ii Earth Observing System (EOS) Tropospheric Emission Spectrometer Jet Propulsion Laboratory #12;TES Validation Report ­ Version F04_04 Data November 5, 2007 Version 3.0

  4. DESIGN OF THE GREAT LAKES OBSERVING SYSTEM ENTERPRISE ARCHITECTURE

    E-Print Network [OSTI]

    DESIGN OF THE GREAT LAKES OBSERVING SYSTEM ENTERPRISE ARCHITECTURE T.J. Dekker1 , J.V. DePinto1 , S, collaborative, and consensus-based enterprise architecture design process was conducted under the direction that will achieve an integrated, comprehensive, and sustainable observing system enterprise for the Great Lakes

  5. Seismic Observation Systems in Nagoya University and Publication of Data

    E-Print Network [OSTI]

    Southern California, University of

    Seismic Observation Systems in Nagoya University and Publication of Data Nobuo Fukuwa,a) Jun Tobita,b) and Hiroaki Kojimac) This paper reports the current situation of the seismic monitoring program conducted by Nagoya University. First, the system for observing seismic ground motion in the Tokai Region is described

  6. Aerosol collection characteristics of ambient aerosol samplers 

    E-Print Network [OSTI]

    Ortiz, Carlos A

    1978-01-01T23:59:59.000Z

    . These samplers have an effic1ency approach1ng 100 percent for particles for which the gravitational and 1nertial forces are small (less than approximately 5 um); however, for larger-sized part1cles the efficiency is quite variable and depends not only upon.... According to Agarwal, representative samples can be collected by an aerosol instrument without meeting the Davies criter1a. Raynor ( 7), with the aid of a wind tunnel, observed the effects of environmental and physical parameters on the entrance effic1...

  7. AEROSOL, CLOUDS, AND CLIMATE CHANGE

    SciTech Connect (OSTI)

    SCHWARTZ, S.E.

    2005-09-01T23:59:59.000Z

    Earth's climate is thought to be quite sensitive to changes in radiative fluxes that are quite small in absolute magnitude, a few watts per square meter, and in relation to these fluxes in the natural climate. Atmospheric aerosol particles exert influence on climate directly, by scattering and absorbing radiation, and indirectly by modifying the microphysical properties of clouds and in turn their radiative effects and hydrology. The forcing of climate change by these indirect effects is thought to be quite substantial relative to forcing by incremental concentrations of greenhouse gases, but highly uncertain. Quantification of aerosol indirect forcing by satellite- or ground-based remote sensing has proved quite difficult in view of inherent large variation in the pertinent observables such as cloud optical depth, which is controlled mainly by liquid water path and only secondarily by aerosols. Limited work has shown instances of large magnitude of aerosol indirect forcing, with local instantaneous forcing upwards of 50 W m{sup 66}-2. Ultimately it will be necessary to represent aerosol indirect effects in climate models to accurately identify the anthropogenic forcing at present and over secular time and to assess the influence of this forcing in the context of other forcings of climate change. While the elements of aerosol processes that must be represented in models describing the evolution and properties of aerosol particles that serve as cloud condensation particles are known, many important components of these processes remain to be understood and to be represented in models, and the models evaluated against observation, before such model-based representations can confidently be used to represent aerosol indirect effects in climate models.

  8. Aircraft Observations of Aerosol Composition and Ageing in New England and Mid-Atlantic States during the Summer 2002 New England Air Quality Study Field Campaign

    SciTech Connect (OSTI)

    Kleinman, Lawrence I.; Daum, Peter H.; Lee, Y.- N.; Senum, Gunar; Springston, Stephen R.; Wang, Jian; Berkowitz, Carl M.; Hubbe, John M.; Zaveri, Rahul A.; Brechtel, Fred J.; Jayne, J. T.; Onasch, Timothy B.; Worsnop, Douglas R.

    2007-05-11T23:59:59.000Z

    Aerosol chemical composition, size distributions, and optical properties were measured during 17 aircraft flights in New England and Middle Atlantic States as part of the summer 2002 NEAQS field campaign. An Aerodyne Aerosol Mass Spectrometer (AMS) was operated with a measurement cycle of 30 s, about an order of magnitude faster than used for ground-based measurements. Noise levels within a single measurement period were sub ?g m-3. Volume data derived from the AMS were compared with volume measurements from a PCASP optical particle detector and an Scanning Mobility Particle Spectrometer (SMPS); calculated light scattering was compared with measured values from an integrating nephelometer. The median ratio for AMS/SMPS volume was 1.25; the median ratio for AMS/nephelometer scattering was 1.18. Size spectra were compared for subsets of samples with different effective diameters (Deff). There is good agreement between the AMS, PCASP, and SMPS spectra for larger values of Deff but an unexplained over-prediction in the AMS for small values. A dependence of the AMS collection efficiency on aerosol acidity was quantified by a comparison between AMS and PCASP volumes in 2 high sulfate plumes. Average aerosol concentrations were 11 ?g m-3. The organic content was high in comparison to monitoring data from the IMPROVE network, varying from 70% in clean air to 40% in high concentration sulfate plumes. The ratio of organic aerosol to CO and light absorption acting were examined as a function of photochemical age. CO is a conservative tracer for urban emissions and light absorption is a surrogate for black carbon which is also conservative. Comparisons were made to surface ratios measured under conditions where there is little secondary organic aerosol (SOA). An increase in these ratios relative to surface values indicates that 70 - 80% of the organic aerosol in polluted air masses was secondary. Most of this SOA is rapidly formed within a few hours. At longer time scales there is a slow accumulation of organic aerosol and a slow increase in light absorption per unit mass of black carbon. Our results demonstrate the utility of the AMS as a rapid response instrument suitable for aircraft operations.

  9. Rule-based system architecting of Earth observation satellite systems

    E-Print Network [OSTI]

    Selva Valero, Daniel

    2012-01-01T23:59:59.000Z

    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 ...

  10. 6, 1217912197, 2006 Aerosol formation in

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    troposphere and lower stratosphere. The model implements a first order scheme for resolving the aerosol size distribution within its geometric size10 sections, which efficiently suppresses numerical diffusion. We operate removes freshly nucleated particles by coagulation. The observation of high ultrafine aerosol

  11. Integrating spacecraft and aircraft in Earth Observation System architectures

    E-Print Network [OSTI]

    Suarez, Brandon H

    2011-01-01T23:59:59.000Z

    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. ...

  12. Parameterizations of Cloud Microphysics and Indirect Aerosol Effects

    SciTech Connect (OSTI)

    Tao, Wei-Kuo [NASA/GSFC] [NASA/GSFC

    2014-05-19T23:59:59.000Z

    1. OVERVIEW Aerosols and especially their effect on clouds are one of the key components of the climate system and the hydrological cycle [Ramanathan et al., 2001]. Yet, the aerosol effect on clouds remains largely unknown and the processes involved not well understood. A recent report published by the National Academy of Science states "The greatest uncertainty about the aerosol climate forcing - indeed, the largest of all the uncertainties about global climate forcing - is probably the indirect effect of aerosols on clouds [NRC, 2001]." The aerosol effect on clouds is often categorized into the traditional "first indirect (i.e., Twomey)" effect on the cloud droplet sizes for a constant liquid water path [Twomey, 1977] and the "semi-direct" effect on cloud coverage [e.g., Ackerman et al., 2000]. Enhanced aerosol concentrations can also suppress warm rain processes by producing a narrow droplet spectrum that inhibits collision and coalescence processes [e.g., Squires and Twomey, 1961; Warner and Twomey, 1967; Warner, 1968; Rosenfeld, 1999]. The aerosol effect on precipitation processes, also known as the second type of aerosol indirect effect [Albrecht, 1989], is even more complex, especially for mixed-phase convective clouds. Table 1 summarizes the key observational studies identifying the microphysical properties, cloud characteristics, thermodynamics and dynamics associated with cloud systems from high-aerosol continental environments. For example, atmospheric aerosol concentrations can influence cloud droplet size distributions, warm-rain process, cold-rain process, cloud-top height, the depth of the mixed phase region, and occurrence of lightning. In addition, high aerosol concentrations in urban environments could affect precipitation variability by providing an enhanced source of cloud condensation nuclei (CCN). Hypotheses have been developed to explain the effect of urban regions on convection and precipitation [van den Heever and Cotton, 2007 and Shepherd, 2005]. Recently, a detailed spectral-bin microphysical scheme was implemented into the Goddard Cumulus Ensemble (GCE) model. Atmospheric aerosols are also described using number density size-distribution functions. A spectral-bin microphysical model is very expensive from a computational point of view and has only been implemented into the 2D version of the GCE at the present time. The model is tested by studying the evolution of deep tropical clouds in the west Pacific warm pool region and summertime convection over a mid-latitude continent with different concentrations of CCN: a low "clean" concentration and a high "dirty" concentration. The impact of atmospheric aerosol concentration on cloud and precipitation will be investigated. 2. MODEL DESCRIPTION AND CASE STUDIES 2.1 GCE MODEL The model used in this study is the 2D version of the GCE model. Modeled flow is anelastic. Second- or higher-order advection schemes can produce negative values in the solution. Thus, a Multi-dimensional Positive Definite Advection Transport Algorithm (MPDATA) has been implemented into the model. All scalar variables (potential temperature, water vapor, turbulent coefficient and all five hydrometeor classes) use forward time differencing and the MPDATA for advection. Dynamic variables, u, v and w, use a second-order accurate advection scheme and a leapfrog time integration (kinetic energy semi-conserving method). Short-wave (solar) and long-wave radiation as well as a subgrid-scale TKE turbulence scheme are also included in the model. Details of the model can be found in Tao and Simpson (1993) and Tao et al. (2003). 2.2 Microphysics (Bin Model) The formulation of the explicit spectral-bin microphysical processes is based on solving stochastic kinetic equations for the size distribution functions of water droplets (cloud droplets and raindrops), and six types of ice particles: pristine ice crystals (columnar and plate-like), snow (dendrites and aggregates), graupel and frozen drops/hail. Each type is described by a special size distribution function containing 33 categories (bin

  13. A cooperative control algorithm for camera based observational systems.

    SciTech Connect (OSTI)

    Young, Joseph G.

    2012-01-01T23:59:59.000Z

    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.

  14. OBSERVING LYAPUNOV EXPONENTS OF INFINITE-DIMENSIONAL DYNAMICAL SYSTEMS

    E-Print Network [OSTI]

    Ott, William

    OBSERVING LYAPUNOV EXPONENTS OF INFINITE-DIMENSIONAL DYNAMICAL SYSTEMS WILLIAM OTT, MAURICIO A. RIVAS, AND JAMES WEST Abstract. Can the Lyapunov exponents of infinite-dimensional dynamical systems spaces generated by evolution partial differential equations. Contents 1. Introduction 1 1.1. Lyapunov

  15. Internal and Boundary Observability Estimates for the Heterogeneous Maxwell's System

    SciTech Connect (OSTI)

    Nicaise, Serge [Universite de Valenciennes et du Hainaut Cambresis, MACS, Institut des Sciences et Techniques de Valenciennes, 59313 Valenciennes Cedex 9 (France)], E-mail: snicaise@univ-valenciennes.fr; Pignotti, Cristina [Dipartimento di Matematica Pura e Applicata, Universita di L'Aquila, Via Vetoio, Loc. Coppito, 67010 L'Aquila (Italy)], E-mail: pignotti@univqaq.it

    2006-06-15T23:59:59.000Z

    Observability estimates for Maxwell's system with variable coefficients are established using the differential geometry method recently developed for scalar wave equations.The main tool is that Maxwell's system is reducible to a perturbed vectorial wave equation with a decoupled principal part.

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

    E-Print Network [OSTI]

    Irshad, Hammad

    2002-01-01T23:59:59.000Z

    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...

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

    SciTech Connect (OSTI)

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

    2011-12-02T23:59:59.000Z

    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.

  18. aerosol retrieval validation: Topics by E-print Network

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

    off the coast of Chile and Peru, where aerosol-cloud interactions are important to the energy balance (15), and limitations in current observing and modeling capabilities...

  19. alkali sulfate aerosol: Topics by E-print Network

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

    chemical transport model and comparison with observations integrals over the aerosol size distribution when only the lower-order moments of the distribution are known...

  20. analysis od aerosol: Topics by E-print Network

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

    closely. The retrieval produces a tighter fit to the RSS data. Climatologies Aerosol size distribution climatology used in GISS GCM does not agree with observations Liu et...

  1. acidic sulfate aerosols: Topics by E-print Network

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

    chemical transport model and comparison with observations integrals over the aerosol size distribution when only the lower-order moments of the distribution are known...

  2. A single-particle characterisation of a mobile Versatile Aerosol Concentration Enrichment System for exposure studies 

    E-Print Network [OSTI]

    Freney, Evelyn; Heal, Mathew R; Donovan, Robert J; Mills, Nicholas; Newby, David; Donaldson, Ken; Fokkens, Paul; Cassee, Flemming

    2006-01-01T23:59:59.000Z

    Enrichment System (VACES) contained within the Mobile Ambient Particle Concentrator Exposure Laboratory (MAPCEL). The data were collected during a study of human exposure to CAPs, in Edinburgh (UK), in February-March 2004. The air flow prior to, and post...

  3. Aerosol collection characteristics of ambient aerosol samplers

    E-Print Network [OSTI]

    Ortiz, Carlos A

    1978-01-01T23:59:59.000Z

    are contained in Appendix C. Dichotomous Sam ler The basic principle of operation of the dichotomous, Figure 9, is that aerosol particles are passed through an acceleration nozzle where the particle velocity is increased to a speed V. at the nozzle exit... AEROSOL COLLECTION CHARACTERISTICS OF AMBIENT AEROSOL SAMPLERS A Thesis by CARLOS A. ORTIZ Submitted to the Graduate College of Texas ARM University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE December 1978...

  4. Time evolution of observable properties of parametrized systems

    E-Print Network [OSTI]

    P. Hajicek

    1996-12-18T23:59:59.000Z

    A short review of some recent work on the problem of time and of observables for the reparametrization invariant systems is given. A talk presented at the Second Meeting on Constraint Dynamics and Quantum Gravity at Santa Marguerita Ligure, September 17--21 1996.

  5. Aerosol mobility size spectrometer

    DOE Patents [OSTI]

    Wang, Jian (Port Jefferson, NY); Kulkarni, Pramod (Port Jefferson Station, NY)

    2007-11-20T23:59:59.000Z

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

  6. Design of coherent quantum observers for linear quantum systems

    E-Print Network [OSTI]

    Shanon L. Vuglar; Hadis Amini

    2015-01-27T23:59:59.000Z

    Quantum versions of control problems are often more difficult than their classical counterparts because of the additional constraints imposed by quantum dynamics. For example, the quantum LQG and quantum H infinity optimal control problems remain open. To make further progress, new, systematic and tractable methods need to be developed. This paper gives three algorithms for designing coherent observers, i.e., quantum systems that are connected to a quantum plant and their outputs provide information about the internal state of the plant. Importantly, coherent observers avoid measurements of the plant outputs. We compare our coherent observers with a classical (measurement-based) observer by way of an example involving an optical cavity with thermal and vacuum noises as inputs.

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

    SciTech Connect (OSTI)

    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

    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.

  8. Aerosol tests conducted at Aberdeen Proving Grounds MD.

    SciTech Connect (OSTI)

    Brockmann, John E.; Lucero, Daniel A.; Servantes, Brandon Lee; Hankins, Matthew Granholm

    2012-06-01T23:59:59.000Z

    Test data are reported that demonstrate the deposition from a spray dispersion system (Illinois Tool Works inductively charging rotary atomization nozzle) for application of decontamination solution to various surfaces in the passenger cabin of a Boeing 737 aircraft. The decontamination solution (EnviroTru) was tagged with a known concentration of fluorescein permitting determination of both airborne decontaminant concentration and surface deposited decontaminant solution so that the effective deposition rates and surface coverage could be determined and correlated with the amount of material sprayed. Six aerosol dispersion tests were conducted. In each test, aluminum foil deposition coupons were set out throughout the passenger area and the aerosol was dispersed. The aerosol concentration was measured with filter samplers as well as with optical techniques Average aerosol deposition ranged from 3 to 15 grams of decontamination solution per square meter. Some disagreement was observed between various instruments utilizing different measurement principles. These results demonstrate a potentially effective method to disperse decontaminant to interior surfaces of a passenger aircraft.

  9. Black carbon aerosols and the third polar ice cap

    SciTech Connect (OSTI)

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

    2010-04-15T23:59:59.000Z

    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.

  10. WRF-Chem Simulations of Aerosols and Anthropogenic Aerosol Radiative Forcing in East Asia

    SciTech Connect (OSTI)

    Gao, Yi; Zhao, Chun; Liu, Xiaohong; Zhang, Meigen; Leung, Lai-Yung R.

    2014-08-01T23:59:59.000Z

    This study aims to provide a first comprehensive evaluation of WRF-Chem for modeling aerosols and anthropogenic aerosol radiative forcing (RF) over East Asia. Several numerical experiments were conducted from November 2007 to December 2008. Comparison between model results and observations shows that the model can generally reproduce the observed spatial distributions of aerosol concentration, aerosol optical depth (AOD) and single scattering albedo (SSA) from measurements at different sites, including the relatively higher aerosol concentration and AOD over East China and the relatively lower AOD over Southeast Asia, Korean, and Japan. The model also depicts the seasonal variation and transport of pollutions over East Asia. Particulate matter of 10 um or less in the aerodynamic diameter (PM10), black carbon (BC), sulfate (SO42-), nitrate (NO3-) and ammonium (NH4+) concentrations are higher in spring than other seasons in Japan due to the pollutant transport from polluted area of East Asia. AOD is high over Southwest and Central China in winter, spring and autumn and over North China in summer while is low over South China in summer due to monsoon precipitation. SSA is lowest in winter and highest in summer. The model also captures the dust events at the Zhangye site in the semi-arid region of China. Anthropogenic aerosol RF is estimated to range from -5 to -20 W m-2 over land and -20 to -40 W m-2 over ocean at the top of atmosphere (TOA), 5 to 30 W m-2 in the atmosphere (ATM) and -15 to -40 W m-2 at the bottom (BOT). The warming effect of anthropogenic aerosol in ATM results from BC aerosol while the negative aerosol RF at TOA is caused by scattering aerosols such as SO4 2-, NO3 - and NH4+. Positive BC RF at TOA compensates 40~50% of the TOA cooling associated with anthropogenic aerosol.

  11. Collaborative process control: Observation of tracks generated by PLM system

    E-Print Network [OSTI]

    Elkadiri, Soumaya; Delattre, Miguel; Bouras, Abdelaziz

    2008-01-01T23:59:59.000Z

    This paper aims at analyzing the problems related to collaborative work using a PLM system. This research is mainly focused on the organisational aspects of SMEs involved in networks composed of large companies, subcontractors and other industrial partners. From this analysis, we propose the deployment of an approach based on an observation process of tracks generated by PLM system. The specific contributions are of two fold. First is to identify the brake points of collaborative work. The second, thanks to the exploitation of generated tracks, it allows reducing risks by reacting in real time to the incidents or dysfunctions that may occur. The overall system architecture based on services technology and supporting the proposed approach is described, as well as associated prototype developed using an industrial PLM system.

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

    SciTech Connect (OSTI)

    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

    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 China’s 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.

  13. Algorithms, Protocols & Systems for Remote Observation Using Networked Robotic Cameras

    E-Print Network [OSTI]

    Qin, Ni

    2010-01-16T23:59:59.000Z

    assist in waste cleanup using Point- and-Direct (PAD) commands. Users point to cleanup locations in a shared image and a robot excavates each location in turn. Recent developments in MOSR systems can be found in [26,27]. In [27] Goldberg et al. propose...ALGORITHMS, PROTOCOLS AND SYSTEMS FOR REMOTE OBSERVATION USING NETWORKED ROBOTIC CAMERAS A Dissertation by NI QIN Submitted to the O?ce of Graduate Studies of Texas A&M University in partial fulflllment of the requirements for the degree of DOCTOR...

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

    SciTech Connect (OSTI)

    Koch, D

    2011-03-20T23:59:59.000Z

    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 (10–20 km) until 5–10 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).

  15. Mechanisms of aerosol-forced AMOC variability in a state of the art climate model

    E-Print Network [OSTI]

    with a new state-of-the-art Earth system model. Anthropogenic aerosols have previously been highlighted anthropogenic aerosols force a strengthening of the AMOC by up to 20% in our state-of-the-art Earth system model

  16. Parameter exploration of optically trapped liquid aerosols

    E-Print Network [OSTI]

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

    2010-06-24T23:59:59.000Z

    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.

  17. Capstone Depleted Uranium Aerosols: Generation and Characterization

    SciTech Connect (OSTI)

    Parkhurst, MaryAnn; Szrom, Fran; Guilmette, Ray; Holmes, Tom; Cheng, Yung-Sung; Kenoyer, Judson L.; Collins, John W.; Sanderson, T. Ellory; Fliszar, Richard W.; Gold, Kenneth; Beckman, John C.; Long, Julie

    2004-10-19T23:59:59.000Z

    In a study designed to provide an improved scientific basis for assessing possible health effects from inhaling depleted uranium (DU) aerosols, a series of DU penetrators was fired at an Abrams tank and a Bradley fighting vehicle. A robust sampling system was designed to collect aerosols in this difficult environment and continuously monitor the sampler flow rates. Aerosols collected were analyzed for uranium concentration and particle size distribution as a function of time. They were also analyzed for uranium oxide phases, particle morphology, and dissolution in vitro. The resulting data provide input useful in human health risk assessments.

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

    SciTech Connect (OSTI)

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

    2013-05-20T23:59:59.000Z

    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 Chemistryâ??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 Earthâ??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.

  19. Atmospheric Aerosol Systems | EMSL

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

    temperature. In... Stability Of Nanoclusters In 14YWT Oxide Dispersion Strengthened Steel Under Heavy Ion-irradiation By Atom Probe Tomography. 14YWT oxide dispersion...

  20. Attachment of radon progeny to cigarette-smoke aerosols

    SciTech Connect (OSTI)

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

    1995-05-01T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

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

    2011-07-06T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

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

    2012-10-20T23:59:59.000Z

    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.

  3. The behavior of constant rate aerosol reactors

    SciTech Connect (OSTI)

    Friedlander, S.K.

    1982-01-01T23:59:59.000Z

    An aerosol reactor is a gaseous system in which fine particles are formed by chemical reaction in either a batch or flow process. The particle sizes of interest range from less than 10 angstrom (molecular clusters) to 10 ..mu..m. Such reactors may be operated to study the aerosol formation process, as in a smog reactor, or to generate a product such as a pigment or a catalytic aerosol. Aerosol reactors can be characterized by three temporal or spatial zones or regions of operation for batch and flow reactors, respectively. In zone I, chemical reaction results in the formation of condensable molecular products which nucleate and form very high concentrations of small particles. The number density depends on the concentration of preexisting aerosol. Zone II is a transition region in which the aerosol number concentration levels off as a result of hetergeneous condensation by the stable aerosol. In zone III coagulation becomes sufficiently rapid to reduce the particle number concentration. There may be a zone IV in which agglomerates form.

  4. Influence of moisture on the behavior of aerosols

    SciTech Connect (OSTI)

    Adams, R.E.; Longest, A.W.; Tobias, M.L.

    1986-01-01T23:59:59.000Z

    The behavior of aerosols assumed to be characteristic of those generated during light water reactor (LWR) accident sequences and released into containment has been studied in the Nuclear Safety Pilot Plant (NSPP) located at the Oak Ridge National Laboratory (ORNL). It has been observed that in a saturated steam-air environment a change occurs in the shape of aerosol agglomerates of U/sub 3/O/sub 8/ aerosol, Fe/sub 2/O/sub 3/ aerosol, and mixed U/sub 3/O/sub 8/-Fe/sub 2/O/sub 3/ aerosol from branched-chain to spherical, and that the rate of reduction in the airborne aerosol mass concentration is increased relative to the rate observed in a dry atmosphere. The effect of a steam-air environment on the behavior of concrete aerosol is different. The shape of the agglomerated concrete aerosol is intermediate between branched-chain and spherical and the effect on the rate of reduction in airborne mass concentration appears to be slight. In a related project the shape of an agglomerated Fe/sub 2/O/sub 3/ aerosol was observed to change from branched-chain to spherical at, or near, 100% relative humidity.

  5. Modeling Atmospheric Aerosols V. Rao Kotamarthi

    E-Print Network [OSTI]

    Modeling Atmospheric Aerosols V. Rao Kotamarthi and Yan Feng Climate Research Section Environmental Science Division Argonne National Laboratory #12;Outline Atmospheric Aerosols and gas phase heterogeneous reactions Regional Scales and Atmospheric Aerosols Regional Scale Aerosols: Ganges Valley Aerosol

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

    SciTech Connect (OSTI)

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

    2014-09-20T23:59:59.000Z

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

  7. Recent activities in the Aerosol Generation and Transport Program

    SciTech Connect (OSTI)

    Adams, R.E.

    1984-01-01T23:59:59.000Z

    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.

  8. Observational Techniques for Detecting Planets in Binary Systems

    E-Print Network [OSTI]

    Matthew W. Muterspaugh; Maciej Konacki; Benjamin F. Lane; Eric Pfahl

    2007-05-21T23:59:59.000Z

    Searches for planets in close binary systems explore the degree to which stellar multiplicity inhibits or promotes planet formation. There is a degeneracy between planet formation models when only systems with single stars are studied--several mechanisms appear to be able to produce such a final result. This degeneracy is lifted by searching for planets in binary systems; the resulting detections (or evidence of non-existence) of planets in binaries isolates which models may contribute to how planets form in nature. In this chapter, we consider observational efforts to detect planetary companions to binary stars in two types of hierarchical planet-binary configurations: first ``S-type'' planets which orbit just one of the stars, with the binary period being much longer than the planet's; second, ``P-type'' or circumbinary planets, where the planet simultaneously orbits both stars, and the planetary orbital period is much longer than that of the binary. The S-type planet finding techniques are different for binaries that can or cannot be spatially resolved. For wider systems, techniques reviewed include dualstar interferometric differential astrometry and precision radial velocities. Alternatively, unresolved binaries can be studied using modified dualstar "PHASES-style" differential astrometry or a modification of the radial velocity technique for composite spectra. Should a fortunately aligned--but still long period--binary be found, eclipse timing can also reveal the presence of S-type planets. Methods for detecting P-type planets include the composite-spectra variant of the radial velocity technique and eclipse timing.

  9. Thermodynamic properties of mesoscale convective systems observed during BAMEX

    SciTech Connect (OSTI)

    Correia, James; Arritt, R.

    2008-11-01T23:59:59.000Z

    Dropsonde observations from the Bow-echo and Mesoscale convective vortex EXperiment (BAMEX) are used to document the spatio-temporal variability of temperature, moisture and wind within mesoscale convective systems (MCSs). Onion type sounding structures are found throughout the stratiform region of MCSs but the temperature and moisture variability is large. Composite soundings were constructed and statistics of thermodynamic variability were generated within each sub-region of the MCS. The calculated air vertical velocity helped identify subsaturated downdrafts. We found that lapse rates within the cold pool varied markedly throughout the MCS. Layered wet bulb potential temperature profiles seem to indicate that air within the lowest several km comes from a variety of source regions. We also found that lapse rate transitions across the 0 C level were more common than isothermal, melting layers. We discuss the implications these findings have and how they can be used to validate future high resolution numerical simulations of MCSs.

  10. Arctic Oscillation response to the 1991 Mount Pinatubo eruption: Effects of volcanic aerosols and ozone depletion

    E-Print Network [OSTI]

    Robock, Alan

    of perturbation experiments, the full radiative effects of the observed Pinatubo aerosol cloud were included eruption, which produced the largest global volcanic aerosol cloud in the twentieth century. A seriesArctic Oscillation response to the 1991 Mount Pinatubo eruption: Effects of volcanic aerosols

  11. Observations

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's Possible for RenewableSpeeding accessSpeeding access(SC)Gas and OilPhaseObservation of aof

  12. Observability Criteria and Estimator Design for Stochastic Linear Hybrid Systems

    E-Print Network [OSTI]

    Gummadi, Ramakrishna

    . Alessandri and Coletta [5] proposed a Luenberger observer design methodology for deterministic linear hybrid

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

    SciTech Connect (OSTI)

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

    2009-03-05T23:59:59.000Z

    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.

  14. Cloud-Driven Changes in Aerosol Optical Properties - Final Technical Report

    SciTech Connect (OSTI)

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

    2007-09-30T23:59:59.000Z

    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.

  15. Ganges valley aerosol experiment.

    SciTech Connect (OSTI)

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

    2011-08-01T23:59:59.000Z

    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.

  16. Direct Aerosol Forcing Uncertainty

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

    Mccomiskey, Allison

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

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

    SciTech Connect (OSTI)

    None

    2013-10-18T23:59:59.000Z

    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').

  18. Use of a continuous stirred tank reactor for the study of aqueous aerosol chemistry

    SciTech Connect (OSTI)

    Adkins, C.L.J.

    1988-01-01T23:59:59.000Z

    Atmospheric aerosol chemistry is important in areas ranging from urban air pollution to cloud formation. It has long been supposed that droplet-phase reactions account for a significant fraction of the atmospheric conversion of SO/sub 2/ to sulfate. In this thesis a reactor system is developed to carry out gas-aerosol reactions under humid, ambient-like conditions. The apparatus consists of a continuous stirred tank reactor (CSTR) in which the growth of the aqueous aerosol is measured. Absence of mass transfer limitation, coagulation, and nucleation ensure that particle growth is direct evidence of reaction. Special care is taken to minimize size biasing of the aqueous aerosol in the electrostatics classifier used to measure the reactor feed and effluent distributions. Aerosol behavior in the reactor is modeled assuming an ideal CSTR and, given the solution thermodynamics and equilibrium chemistry, the effluent distribution can be predicted using one of the proposed reaction rate mechanisms. Experiments were performed using a pure MnSO/sub 4/ or a MnSO/sub 4/minus// Na/sub 2/SO/sub 4/ mixture feed aerosol. The relative humidity ranged from 86 to 94% and 0.1 ppm < p/sub SO/sub 2// < 50 ppm. The various rate expressions proposed for this system in the literature resulted in varying estimates of growth. When reactor conditions were similar to those at which the rate expression was determined, the agreement between the predicted and observed distributions improved. This indicates that use of a rate expressions beyond its specified range may result in erroneous predictions.

  19. A satellite ocean color observation operator system for eutrophication assessment in coastal waters

    E-Print Network [OSTI]

    Fontana, Clément

    A satellite ocean color observation operator system for eutrophication assessment in coastal waters: Satellite ocean color Observation operator Eutrophication Remote sensing Radiative transfer modeling

  20. Chemical and physicochemial properties of submicron aerosol agglomerates

    SciTech Connect (OSTI)

    Scripsick, R.C. [Los Alamos National Lab., NM (United States); Ehrman, S.; Friedlander, S.K. [Univ. of California, Los Angeles, CA (United States). Dept. of Chemical Engineering

    1998-12-31T23:59:59.000Z

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory. The formation of nanometer-sized aerosol particles in a premixed methane flame from both solid-phase aerosol precursors and gas-phase precursors was investigated. Techniques were developed to determine the distribution of the individual chemical species as a function of agglomerate size by using inductively coupled plasma atomic emission spectroscopy (ICP-AES). To determine the distribution of chemical species both from particle to particle and within the particles on a nanometer scale, we used the analytical electron microscopy techniques of energy dispersive x-ray spectrometry (EDS) and electron energy loss spectrometry (EELS) coupled with transmission electron microscopy (TEM). The observed distribution of individual chemical species as a function of agglomerate size was linked to the material properties of the solid-phase precursors. For aerosol formed from gas-phase precursors by gas-to-particle conversion, the distribution of species on a manometer scale was found to correspond to the equilibrium phase distribution expected from equilibrium for the system at the flame temperatures.

  1. Aerosol remote sensing in polar regions

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

    Tomasi, C.; Wagener, R.; Kokhanovsky, A. A.; Lupi, A.; Ritter, C.; Smirnov, A.; O Neill, N. T.; Stone, R. S.; Holben, B. N.; Nyeki, S.; Wehrli, C.; Stohl, A.; Mazzola, M.; Lanconelli, C.; Vitale, V.; Stebel, K.; Aaltonen, V.; de Leeuw, G.; Rodriguez, E.; Herber, A. B.; Radionov, V. F.; Zielinski, T.; Petelski, T.; Sakerin, S. M.; Kabanov, D. M.; Xue, Y.; Mei, L.; Istomina, L.; Wagener, R.; McArthur, B.; Sobolewski, P. S.; Kivi, R.; Courcoux, Y.; Larouche, P.; Broccardo, S.; Piketh, S. J.

    2015-01-01T23:59:59.000Z

    Multi-year sets of ground-based sun-photometer measurements conducted at 12 Arctic sites and 9 Antarctic sites were examined to determine daily mean values of aerosol optical thickness ?(?) at visible and near-infrared wavelengths, from which best-fit values of Ångström's exponent ? were calculated. Analysing these data, the monthly mean values of ?(0.50 ?m) and ? and the relative frequency histograms of the daily mean values of both parameters were determined for winter–spring and summer–autumn in the Arctic and for austral summer in Antarctica. The Arctic and Antarctic covariance plots of the seasonal median values of ? versus ?(0.50 ?m) showed: (i) a considerable increase in ?(0.50 ?m) for the Arctic aerosol from summer to winter–spring, without marked changes in ?; and (ii) a marked increase in ?(0.50 ?m) passing from the Antarctic Plateau to coastal sites, whereas ? decreased considerably due to the larger fraction of sea-salt aerosol. Good agreement was found when comparing ground-based sun-photometer measurements of ?(?) and ? at Arctic and Antarctic coastal sites with Microtops measurements conducted during numerous AERONET/MAN cruises from 2006 to 2013 in three Arctic Ocean sectors and in coastal and off-shore regions of the Southern Atlantic, Pacific, and Indian Oceans, and the Antarctic Peninsula. Lidar measurements were also examined to characterise vertical profiles of the aerosol backscattering coefficient measured throughout the year at Ny-Ålesund. Satellite-based MODIS, MISR, and AATSR retrievals of ?(?) over large parts of the oceanic polar regions during spring and summer were in close agreement with ship-borne and coastal ground-based sun-photometer measurements. An overview of the chemical composition of mode particles is also presented, based on in-situ measurements at Arctic and Antarctic sites. Fourteen log-normal aerosol number size-distributions were defined to represent the average features of nuclei, accumulation and coarse mode particles for Arctic haze, summer background aerosol, Asian dust and boreal forest fire smoke, and for various background austral summer aerosol types at coastal and high-altitude Antarctic sites. The main columnar aerosol optical characteristics were determined for all 14 particle modes, based on in-situ measurements of the scattering and absorption coefficients. Diurnally averaged direct aerosol-induced radiative forcing and efficiency were calculated for a set of multimodal aerosol extinction models, using various Bidirectional Reflectance Distribution Function models over vegetation-covered, oceanic and snow-covered surfaces. These gave a reliable measure of the pronounced effects of aerosols on the radiation balance of the surface–atmosphere system over polar regions.

  2. Aerosol remote sensing in polar regions

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

    Tomasi, C.; Wagener, R.; Kokhanovsky, A. A.; Lupi, A.; Ritter, C.; Smirnov, A.; O Neill, N. T.; Stone, R. S.; Holben, B. N.; Nyeki, S.; et al

    2015-01-01T23:59:59.000Z

    Multi-year sets of ground-based sun-photometer measurements conducted at 12 Arctic sites and 9 Antarctic sites were examined to determine daily mean values of aerosol optical thickness ?(?) at visible and near-infrared wavelengths, from which best-fit values of Ångström's exponent ? were calculated. Analysing these data, the monthly mean values of ?(0.50 ?m) and ? and the relative frequency histograms of the daily mean values of both parameters were determined for winter–spring and summer–autumn in the Arctic and for austral summer in Antarctica. The Arctic and Antarctic covariance plots of the seasonal median values of ? versus ?(0.50 ?m) showed: (i)more »a considerable increase in ?(0.50 ?m) for the Arctic aerosol from summer to winter–spring, without marked changes in ?; and (ii) a marked increase in ?(0.50 ?m) passing from the Antarctic Plateau to coastal sites, whereas ? decreased considerably due to the larger fraction of sea-salt aerosol. Good agreement was found when comparing ground-based sun-photometer measurements of ?(?) and ? at Arctic and Antarctic coastal sites with Microtops measurements conducted during numerous AERONET/MAN cruises from 2006 to 2013 in three Arctic Ocean sectors and in coastal and off-shore regions of the Southern Atlantic, Pacific, and Indian Oceans, and the Antarctic Peninsula. Lidar measurements were also examined to characterise vertical profiles of the aerosol backscattering coefficient measured throughout the year at Ny-Ålesund. Satellite-based MODIS, MISR, and AATSR retrievals of ?(?) over large parts of the oceanic polar regions during spring and summer were in close agreement with ship-borne and coastal ground-based sun-photometer measurements. An overview of the chemical composition of mode particles is also presented, based on in-situ measurements at Arctic and Antarctic sites. Fourteen log-normal aerosol number size-distributions were defined to represent the average features of nuclei, accumulation and coarse mode particles for Arctic haze, summer background aerosol, Asian dust and boreal forest fire smoke, and for various background austral summer aerosol types at coastal and high-altitude Antarctic sites. The main columnar aerosol optical characteristics were determined for all 14 particle modes, based on in-situ measurements of the scattering and absorption coefficients. Diurnally averaged direct aerosol-induced radiative forcing and efficiency were calculated for a set of multimodal aerosol extinction models, using various Bidirectional Reflectance Distribution Function models over vegetation-covered, oceanic and snow-covered surfaces. These gave a reliable measure of the pronounced effects of aerosols on the radiation balance of the surface–atmosphere system over polar regions.« less

  3. 7, 55535593, 2007 Nitrate aerosols

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    ACPD 7, 5553­5593, 2007 Nitrate aerosols today and in 2030 S. E. Bauer et al. Title Page Abstract Discussions Nitrate aerosols today and in 2030: importance relative to other aerosol species and tropospheric, 5553­5593, 2007 Nitrate aerosols today and in 2030 S. E. Bauer et al. Title Page Abstract Introduction

  4. Antenna system characteristic and solar radio burst observation

    E-Print Network [OSTI]

    Li, Sha; Chen, Zhijun; Wang, Wei; Liu, Donghao

    2015-01-01T23:59:59.000Z

    Chinese Spectral Radio Heliograph (CSRH) is an advanced aperture synthesis solar radio heliograph, developed by National Astronomical Observatories, Chinese Academy of Sciences independently. It consists of 100 reflector antennas, which are grouped into two antenna arrays (CSRH-I and CSRH-II) for low and high frequency bands respectively. The frequency band of CSRH-I is 0.4-2GHz and for CSRH-II, the frequency band is 2-15GHz. In the antenna and feed system, CSRH uses an Eleven feed to receive signals coming from the Sun, the radiation pattern with lower side lobe and back lobe of the feed is well radiated. The characteristics of gain G and antenna noise temperature T effect the quality of solar radio imaging. For CSRH, measured G is larger than 60 dBi and $ T $ is less than 120K, after CSRH-I was established, we have successfully captured a solar radio burst between 1.2-1.6GHz on November 12, 2010 through this instrument and this event was confirmed through the observation of Solar Broadband Radio Spectromete...

  5. Chemical Composition and Sources of Coastal Marine Aerosol Particles during the 2008 VOCALS-REx Campaign

    SciTech Connect (OSTI)

    Lee, Y.- N.; Springston, S.; Jayne, John T.; Wang, Jian; Hubbe, John M.; Senum, Gunnar I.; Kleinman, Lawrence I.; Daum, Peter H.

    2014-05-23T23:59:59.000Z

    The chemical composition of aerosol particles (Dp 1.5 ?m) was measured over the southeast Pacific Ocean during the VAMOS (Variability of the American Monsoon Systems) Ocean-Cloud-Atmosphere-Land Study Regional Experiment (VOCALS-Rex) between 16 October and 15 November 2008 using the US Department of Energy (DOE) G-1 aircraft. The objective of these flights was to gain an understanding of the sources and evolution of these aerosols, and of how they interact with the marine stratus cloud layer that prevails in this region of the globe. Our measurements showed that the marine boundary layer (MBL) aerosol mass was dominated by non-sea-salt SO2?4, followed by Na+, Cl?, Org (total organics), NH+4 , and NO?3 , in decreasing order of importance; CH3SO?3 (MSA), Ca2+, and K+ rarely exceeded their limits of detection. Aerosols were strongly acidic with a NH+4 to SO2?4 equivalents ratio typically < 0.3. Sea-salt aerosol (SSA) particles, represented by NaCl, exhibited Cl? deficits caused by both HNO3 and H2SO4, but for the most part were externally mixed with particles, mainly SO2?4. SSA contributed only a small fraction of the total accumulation mode particle number concentration. It was inferred that all aerosol species (except SSA) were of predominantly continental origin because of their strong land-to-sea concentration gradient. Comparison of relative changes in median values suggests that (1) an oceanic source of NH3 is present between 72° W and 76° W, (2) additional organic aerosols from biomass burns or biogenic precursors were emitted from coastal regions south of 31° S, with possible cloud processing, and (3) free tropospheric (FT) contributions to MBL gas and aerosol concentrations were negligible. The very low levels of CH3SO?3 observed as well as the correlation between SO2?4 and NO?3 (which is thought primarily anthropogenic) suggest a limited contribution of DMS to SO2?4 aerosol production during VOCALS.

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

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

    Sivaraman, Chitra; Flynn, Connor

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

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

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

    Newsom, Rob; Goldsmith, John

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

  8. Toxicity of atmospheric aerosols on marine phytoplankton

    E-Print Network [OSTI]

    2009-01-01T23:59:59.000Z

    metals added from these aerosols to the bioassay incubationsreleased to seawater from the aerosol filters after Author4605 CHEMISTRY Atmospheric aerosol deposition CHEMISTRY

  9. Radiative and climate impacts of absorbing aerosols

    E-Print Network [OSTI]

    Zhu, Aihua

    2010-01-01T23:59:59.000Z

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

  10. BAYESIAN INFERENCE ON INTEGRATED CONTINUITY FLUID FLOWS AND THEIR APPLICATION TO DUST AEROSOLS

    E-Print Network [OSTI]

    Garbe, Christoph S.

    BAYESIAN INFERENCE ON INTEGRATED CONTINUITY FLUID FLOWS AND THEIR APPLICATION TO DUST AEROSOLS Waterloo, Ontario, Canada ABSTRACT The significant role dust aerosols play in the earth's cli- mate system models for aerosol de- tection and atmospheric transport that rely on latent Gaussian Markov random

  11. Spatial and temporal variability of the stratospheric aerosol cloud produced by the 1991 Mount Pinatubo eruption

    E-Print Network [OSTI]

    Robock, Alan

    Experiment (SAGE) II aerosol extinction profiles and aerosol backscatter measured by five lidars, both lidar backscatter profiles at 0.532 mm or 0.694 mm wavelengths to the SAGE II extinction wavelengths a tremendous aerosol load into the stratosphere and produced large perturbations to the climate system

  12. 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

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

    E-Print Network [OSTI]

    Beaucage, Gregory

    1 Nanomaterials from Aerosols Aerosols are suspensions of liquid or solid particles in a gas. Aerosol particles can range in size from molecular-scale to hundreds of microns with a typical example be synthesized by aerosol routes where precursor species are dispersed either in a vapor or in micron

  14. Ice-condenser aerosol tests

    SciTech Connect (OSTI)

    Ligotke, M.W.; Eschbach, E.J.; Winegardner, W.K. (Pacific Northwest Lab., Richland, WA (United States))

    1991-09-01T23:59:59.000Z

    This report presents the results of an experimental investigation of aerosol particle transport and capture using a full-scale height and reduced-scale cross section test facility based on the design of the ice compartment of a pressurized water reactor (PWR) ice-condenser containment system. Results of 38 tests included thermal-hydraulic as well as aerosol particle data. Particle retention in the test section was greatly influenced by thermal-hydraulic and aerosol test parameters. Test-average decontamination factor (DF) ranged between 1.0 and 36 (retentions between {approximately}0 and 97.2%). The measured test-average particle retentions for tests without and with ice and steam ranged between DF = 1.0 and 2.2 and DF = 2.4 and 36, respectively. In order to apparent importance, parameters that caused particle retention in the test section in the presence of ice were steam mole fraction (SMF), noncondensible gas flow rate (residence time), particle solubility, and inlet particle size. Ice-basket section noncondensible flows greater than 0.1 m{sup 3}/s resulted in stable thermal stratification whereas flows less than 0.1 m{sup 3}/s resulted in thermal behavior termed meandering with frequent temperature crossovers between flow channels. 10 refs., 66 figs., 16 tabs.

  15. On Optimal Control of a Class of Partially-Observed Discrete Event Systems

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    On Optimal Control of a Class of Partially-Observed Discrete Event Systems H e rv M a rch a n d theC-observer. Thissubmachineleadstothedesiredsupervisorforthesystem. Keywords: DiscreteEventSystems,SupervisoryControlProblem,Optimality(not) be reached in the controlled system, the Optimal Control under Par- tial Observation problem is solved

  16. Modeling Study of the Effect of Anthropogenic Aerosols on Late Spring Drought in South China

    SciTech Connect (OSTI)

    Hu, Ning; Liu, Xiaohong

    2013-10-01T23:59:59.000Z

    In this study, the mechanisms underlying the decadal variability of late spring precipitation in south China are investigated using the latest version 1 of Community Earth System Model (CESM1). We aim to unravel the effects of different climate forcing agents, such as aerosols and greenhouse gases (GHGs), on the decadal variation of precipitation with transient experiments from pre-industry (for year 1850) to present-day (for year 2000). Our results reveal that: (1) CESM1 can reproduce the climatological features of atmospheric circulation and precipitation for the late spring in south China; (2) Only simulations including the forcing of anthropogenic aerosols can reproduce the observed decreasing trend of late spring precipitation from 1950-2000 in south China; (3) Aerosols affect the decadal change of precipitation mainly by altering the large scale atmospheric circulation, and to a less extent by increasing the lower-tropospheric stability to inhibit the convective precipitation; and (4) In comparison, other climate forcing agents, such as GHGs, have much smaller effects on the decadal change of spring precipitation in south China. Key words: precipitation, aerosols, climate change, south China, Community Earth System Model

  17. Estimation of the WECC System Inertia Using Observed Frequency Transients

    E-Print Network [OSTI]

    David P. Chassin; Zhenyu Huang; Matthew K. Donnelly; Candee Hassler; Enrique Ramirez; Cody Ray

    2004-12-28T23:59:59.000Z

    Computer models being developed to understand the interaction between demand-response technology, power system deregulation and market transformation depend in part on understanding the relationship between system frequency and load-control. Frequency, load, and plant outage events data collected over the last several years have permitted analysis to determine the Western Electricity Coordination Council (WECC) system's inertia during each event. This data was used to evaluate the relationship of system inertia to total load, which is used to model system response to load curtailment programs in next generation power system simulations.

  18. Light Absorption by Secondary Organic Aerosol from ?-Pinene: Effects of Oxidants, Seed Aerosol Acidity, and Relative Humidity

    SciTech Connect (OSTI)

    Song, Chen; Gyawali, Madhu S.; Zaveri, Rahul A.; Shilling, John E.; Arnott, W. Patrick

    2013-10-25T23:59:59.000Z

    It is well known that light absorption from dust and black carbon aerosols has a warming effect on climate while light scattering from sulfate, nitrate, and sea salt aerosols has a cooling effect. However, there are large uncertainties associated with light absorption and scattering by different types of organic aerosols, especially in the near-UV and UV spectral regions. In this paper, we present the results from a systematic laboratory study focused on measuring light absorption by secondary organic aerosols (SOA) generated from ozonolysis or NO3 oxidation of ?-pinene in the presence of neutral and acidic sulfate seed aerosols. Light absorption was monitored using photoacoustic spectrometers at four different wavelengths: 355, 405, 532 and 870 nm. Light absorption at 355 and 405 nm was observed by SOA generated from oxidation of ?-pinene in the presence of acidic sulfate seed aerosols, under dry conditions. No absorption was observed when the relative humidity was elevated to greater than 27%, or in the presence of neutral sulfate seed aerosols. The light-absorbing compounds are speculated to be aldol condensation oligomers with organosulfate and organic nitrate groups. The results of this study also indicate that organic nitrates from ?-pinene SOA formed in the presence of neutral sulfate seed aerosols do not appear to absorb near-UV and UV radiation.

  19. Development and Characterization of a Thermodenuder for Aerosol Volatility Measurements

    SciTech Connect (OSTI)

    Dr. Timothy Onasch

    2009-09-09T23:59:59.000Z

    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.

  20. OBSERVED HYBRID OSCILLATIONS IN AN ELECTRICAL DISTRIBUTION SYSTEM Vaibhav Donde

    E-Print Network [OSTI]

    . 1 therefore provide an example of a hybrid limit cycle.1 Analysis of power system large disturbance-changing transformers and switched capacitors. Analysis required a hybrid systems framework, due to the non from usual power system oscillations [1]: 1) behav- iour was quite non-smooth, and 2) the oscillation

  1. Introduction Dust aerosols affect visibility, perturb the radiative energy balance

    E-Print Network [OSTI]

    Wang, Jun

    Sunphotometer and air temperature from ground observations. Model Flow Chart GOES-8 06/28/00 1145 UTC -90 -80Introduction Dust aerosols affect visibility, perturb the radiative energy balance of the earth

  2. aerosolized bacillus anthracis: Topics by E-print Network

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

    and remotely sensed aerosol observations. William D. Collins; Phillip J. Rasch; Brian E. Eaton; Boris V. Khattatov; Jean-francois Lamarque; C. Zender 2001-01-01 118 THESE DE...

  3. Results from simulated upper-plenum aerosol transport and aerosol resuspension experiments

    SciTech Connect (OSTI)

    Wright, A.L.; Pattison, W.L.

    1984-01-01T23:59:59.000Z

    Recent calculational results published as part of the Battelle-Columbus BMI-2104 source term study indicate that, for some LWR accident sequences, aerosol deposition in the reactor primary coolant system (PCS) can lead to significant reductions in the radionuclide source term. Aerosol transport and deposition in the PCS have been calculated in this study using the TRAP-MELT 2 computer code, which was developed at Battelle-Columbus; the status of validation of the TRAP-MELT 2 code has been described in an Oak Ridge National Laboratory (ORNL) report. The objective of the ORNL TRAP-MELT Validation Project, which is sponsored by the Fuel Systems Behavior Research Branch of the US Nuclear Regulatory Commission, is to conduct simulated reactor-vessel upper-plenum aerosol deposition and transport tests. The results from these tests will be used in the ongoing effort to validate TRAP-MELT 2. The TRAP-MELT Validation Project includes two experimental subtasks. In the Aerosol Transport Tests, aerosol transport in a vertical pipe is being studied; this geometry was chosen to simulate aerosol deposition and transport in the reactor-vessel upper-plenum. To date, four experiments have been performed; the results from these tests are presented in this paper. 7 refs., 4 figs., 4 tabs.

  4. Aerosol Sampler Operations Manual

    E-Print Network [OSTI]

    Fischer, Emily V.

    -1123 Laboratory FAX (916) 752-4107 Standard Operating Procedures Technical Information Document TI 201A #12;TI 201.................................................................................................................................................. 3 1.0 Weekly Maintenance ProceduresIMPROVE Aerosol Sampler Operations Manual February 10, 1997 Air Quality Group Crocker Nuclear

  5. Mathematical strategies for filtering complex systems: Regularly spaced sparse observations

    SciTech Connect (OSTI)

    Harlim, J. [Department of Mathematics and Center for Atmosphere and Ocean Science, Courant Institute of Mathematical Sciences, New York University, 251 Mercer Street, New York, NY 10012 (United States)], E-mail: jharlim@cims.nyu.edu; Majda, A.J. [Department of Mathematics and Center for Atmosphere and Ocean Science, Courant Institute of Mathematical Sciences, New York University, 251 Mercer Street, New York, NY 10012 (United States)

    2008-05-01T23:59:59.000Z

    Real time filtering of noisy turbulent signals through sparse observations on a regularly spaced mesh is a notoriously difficult and important prototype filtering problem. Simpler off-line test criteria are proposed here as guidelines for filter performance for these stiff multi-scale filtering problems in the context of linear stochastic partial differential equations with turbulent solutions. Filtering turbulent solutions of the stochastically forced dissipative advection equation through sparse observations is developed as a stringent test bed for filter performance with sparse regular observations. The standard ensemble transform Kalman filter (ETKF) has poor skill on the test bed and even suffers from filter divergence, surprisingly, at observable times with resonant mean forcing and a decaying energy spectrum in the partially observed signal. Systematic alternative filtering strategies are developed here including the Fourier Domain Kalman Filter (FDKF) and various reduced filters called Strongly Damped Approximate Filter (SDAF), Variance Strongly Damped Approximate Filter (VSDAF), and Reduced Fourier Domain Kalman Filter (RFDKF) which operate only on the primary Fourier modes associated with the sparse observation mesh while nevertheless, incorporating into the approximate filter various features of the interaction with the remaining modes. It is shown below that these much cheaper alternative filters have significant skill on the test bed of turbulent solutions which exceeds ETKF and in various regimes often exceeds FDKF, provided that the approximate filters are guided by the off-line test criteria. The skill of the various approximate filters depends on the energy spectrum of the turbulent signal and the observation time relative to the decorrelation time of the turbulence at a given spatial scale in a precise fashion elucidated here.

  6. Observational Analysis of the Predictability of Mesoscale Convective Systems ISRAEL L. JIRAK AND WILLIAM R. COTTON

    E-Print Network [OSTI]

    Observational Analysis of the Predictability of Mesoscale Convective Systems ISRAEL L. JIRAK (Manuscript received 30 December 2005, in final form 4 October 2006) ABSTRACT Mesoscale convective systems of usefulness in operational forecasting. 1. Introduction Mesoscale convective systems (MCSs) frequently de

  7. Estimation of WECC System Inertia Using Observed Frequency Transients

    SciTech Connect (OSTI)

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

    2005-04-19T23:59:59.000Z

    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.

  8. System architecting of a campaign of earth observing satellites

    E-Print Network [OSTI]

    Colson, Justin M

    2008-01-01T23:59:59.000Z

    Given the current level of concern over anthropogenic climate change, and the ongoing debate worldwide regarding what action should be taken to reduce and reverse future warming, the ability to collect data on Earth system ...

  9. H observer for time-delay systems Application to FDI for irrigation canals

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    H observer for time-delay systems Application to FDI for irrigation canals N. Bedjaoui, X. Litrico and isolation for time-varying delayed systems. It consists to develop a H observer that generates residuals occur on the regulation gates of an irrigation canal. The observer design uses a simplified approximate

  10. Recycling of quantum information: Multiple observations of quantum systems

    E-Print Network [OSTI]

    Peter Rapcan; John Calsamiglia; Ramon Munoz-Tapia; Emilio Bagan; Vladimir Buzek

    2007-08-08T23:59:59.000Z

    Given a finite number of copies of an unknown qubit state that have already been measured optimally, can one still extract any information about the original unknown state? We give a positive answer to this question and quantify the information obtainable by a given observer as a function of the number of copies in the ensemble, and of the number of independent observers that, one after the other, have independently measured the same ensemble of qubits before him. The optimality of the protocol is proven and extensions to other states and encodings are also studied. According to the general lore, the state after a measurement has no information about the state before the measurement. Our results manifestly show that this statement has to be taken with a grain of salt, specially in situations where the quantum states encode confidential information.

  11. Characterizing the formation of secondary organic aerosols

    SciTech Connect (OSTI)

    Lunden, Melissa; Black, Douglas; Brown, Nancy

    2004-02-01T23:59:59.000Z

    Organic aerosol is an important fraction of the fine particulate matter present in the atmosphere. This organic aerosol comes from a variety of sources; primary organic aerosol emitted directly from combustion process, and secondary aerosol formed in the atmosphere from condensable vapors. This secondary organic aerosol (SOA) can result from both anthropogenic and biogenic sources. In rural areas of the United States, organic aerosols can be a significant part of the aerosol load in the atmosphere. However, the extent to which gas-phase biogenic emissions contribute to this organic load is poorly understood. Such an understanding is crucial to properly apportion the effect of anthropogenic emissions in these rural areas that are sometimes dominated by biogenic sources. To help gain insight on the effect of biogenic emissions on particle concentrations in rural areas, we have been conducting a field measurement program at the University of California Blodgett Forest Research Facility. The field location includes has been used to acquire an extensive suite of measurements resulting in a rich data set, containing a combination of aerosol, organic, and nitrogenous species concentration and meteorological data with a long time record. The field location was established in 1997 by Allen Goldstein, a professor in the Department of Environmental Science, Policy and Management at the University of California at Berkeley to study interactions between the biosphere and the atmosphere. The Goldstein group focuses on measurements of concentrations and whole ecosystem biosphere-atmosphere fluxes for volatile organic compounds (VOC's), oxygenated volatile organic compounds (OVOC's), ozone, carbon dioxide, water vapor, and energy. Another important collaborator at the Blodgett field location is Ronald Cohen, a professor in the Chemistry Department at the University of California at Berkeley. At the Blodgett field location, his group his group performs measurements of the concentrations of important gas phase nitrogen compounds. Experiments have been ongoing at the Blodgett field site since the fall of 2000, and have included portions of the summer and fall of 2001, 2002, and 2003. Analysis of both the gas and particle phase data from the year 2000 show that the particle loading at the site correlates with both biogenic precursors emitted in the forest and anthropogenic precursors advected to the site from Sacramento and the Central Valley of California. Thus the particles at the site are affected by biogenic processing of anthropogenic emissions. Size distribution measurements show that the aerosol at the site has a geometric median diameter of approximately 100 nm. On many days, in the early afternoon, growth of nuclei mode particles (<20 nm) is also observed. These growth events tend to occur on days with lower average temperatures, but are observed throughout the summer. Analysis of the size resolved data for these growth events, combined with typical measured terpene emissions, show that the particle mass measured in these nuclei mode particles could come from oxidation products of biogenic emissions, and can serve as a significant route for SOA partitioning into the particle phase. During periods of each year, the effect of emissions for forest fires can be detected at the Blodgett field location. During the summer of 2002 emissions from the Biscuit fire, a large fire located in Southwest Oregon, was detected in the aerosol data. The results show that increases in particle scattering can be directly related to increased black carbon concentration and an appearance of a larger mode in the aerosol size distribution. These results show that emissions from fires can have significant impact on visibility over large distances. The results also reinforce the view that forest fires can be a significant source of black carbon in the atmosphere, which has important climate and visibility. Continuing work with the 2002 data set, particularly the combination of the aerosol and gas phase data, will continue to provide important information o

  12. Role of ammonia chemistry and coarse mode aerosols in global climatological inorganic aerosol distributions

    E-Print Network [OSTI]

    Luo, Chao; Zender, Charles S; Bian, Huisheng; Metzger, Swen

    2007-01-01T23:59:59.000Z

    times of tropospheric aerosols inferred from a global three-sional simulation of 210Pb aerosols. Journal of Geophysicalof sulfate and nitrate aerosol. Atmospheric Environ- ment

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

    E-Print Network [OSTI]

    Bauer, Susanne E.

    2010-01-01T23:59:59.000Z

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

  14. Status of the LWR aerosol containment experiments (LACE) program

    SciTech Connect (OSTI)

    Bloom, G.R.; Dickinson, D.R.; Hilliard, R.K.; McCormack, J.D.; Muhlestein, L.D.; Rahn, F.J.

    1985-01-01T23:59:59.000Z

    The LACE program, sponsored by an international consortium, is investigating inherent aerosol behavior for three postulated high consequence accident sequences; the containment bypass or V-sequence, failure to isolate containment, and delayed containment failure. Six large-scale tests are described which focus on these accident situations and which will be completed in the Containment Systems Test Facility at the Hanford Engineering Development Laboratory. The aerosol generation systems used to generate soluble and insoluble aerosols for the large-scale tests are described. The report then focuses on those tests which deal with the containment bypass accident sequence. Test results are presented and discussed for three containment bypass scoping tests.

  15. Stochastic Modeling and Optimization for Robust Power Management in a Partially Observable System

    E-Print Network [OSTI]

    Qiu, Qinru

    Stochastic Modeling and Optimization for Robust Power Management in a Partially Observable System and issues control commands periodically. Reference [3] models the similar system using the continuous a full observation of the entire system status. In this paper, we propose a new modeling and optimization

  16. An Augmented Reality System for Astronomical Observations Andrei Lintu

    E-Print Network [OSTI]

    Magnor, Marcus

    , but also depends on the visibility, sky brightness and telescope aper- ture. We propose a system which. For projection, a custom-built video projection mod- ule with high contrast and low maximum luminance value fascinated by the starry sky. It is one of the first natural phenomena that was investi- gated by humans

  17. Simulations of Solar System observations in alternative theories of gravity

    E-Print Network [OSTI]

    A. Hees; B. Lamine; S. Reynaud; M. -T. Jaekel; C. Le Poncin-Lafitte; V. Lainey; A. Füzfa; J. -M. Courty; V. Dehant; P. Wolf

    2013-02-27T23:59:59.000Z

    In this communication, we focus on the possibility to test General Relativity (GR) with radioscience experiments. We present simulations of observables performed in alternative theories of gravity using a software that simulates Range/Doppler signals directly from the space time metric. This software allows one to get the order of magnitude and the signature of the modifications induced by an alternative theory of gravity on radioscience signals. As examples, we present some simulations for the Cassini mission in Post-Einsteinian gravity (PEG) and with Standard Model Extension (SME).

  18. 6, 11791198, 2006 Aerosols closing

    E-Print Network [OSTI]

    Boyer, Edmond

    ACPD 6, 1179­1198, 2006 Aerosols closing open Benard cells D. Rosenfeld et al. Title Page Abstract of precipitation by aerosols D. Rosenfeld1 , Y. J. Kaufman2 , and I. Koren3 1 Institute of Earth Sciences­1198, 2006 Aerosols closing open Benard cells D. Rosenfeld et al. Title Page Abstract Introduction

  19. 8, 14571503, 2008 The aerosol

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    ACPD 8, 1457­1503, 2008 The aerosol distribution in Europe V. Matthias Title Page Abstract Discussions The aerosol distribution in Europe derived with the Community Multiscale Air Quality (CMAQ) model.matthias@gkss.de) 1457 #12;ACPD 8, 1457­1503, 2008 The aerosol distribution in Europe V. Matthias Title Page Abstract

  20. 5, 79658026, 2005 Simulating aerosol

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    composition, number concentration, and size distribution of the global submicrometer aerosol. The present, coagulation, condensation, nucleation of sulfuric acid vapor, aerosol chemistry, cloud processing, and sizeACPD 5, 7965­8026, 2005 Simulating aerosol microphysics with ECHAM/MADE A. Lauer et al. Title Page

  1. VARIATION OF AEROSOL OPTICAL PROPERTIES

    E-Print Network [OSTI]

    Schwartz, Stephen E.

    radiative forcing due to the aerosol, W m-2 FT is the solar constant, W m-2 Ac is the fractional cloud cover;APPROACH TO MODELING AEROSOL RADIATIVE EFFECTS Transport Chemistry Microphysics Removal ModelEmissions Size-distributed Composition Optical Properties Radiative Effects Optics Model Radiation Transfer Model #12;CLASSES OF AEROSOL

  2. Designing a Stochastic Adaptive Impulsive Observer for Stochastic Linear and Nonlinear Impulsive Systems

    SciTech Connect (OSTI)

    Ayati, Moosa [Department of Applied Mathematics, University of Waterloo, Waterloo, Ontario (Canada); Faculty of Electrical and Computer Engineering, K. N. Toosi University of Technology, Tehran (Iran, Islamic Republic of); Alwan, Mohamad; Liu Xinzhi [Department of Applied Mathematics, University of Waterloo, Waterloo, Ontario (Canada); Khaloozadeh, Hamid [Faculty of Electrical and Computer Engineering, K. N. Toosi University of Technology, Tehran (Iran, Islamic Republic of)

    2011-11-30T23:59:59.000Z

    State observation (estimation) is a very important issue in system analysis and control. This paper develops a new observer called Stochastic Adaptive Impulsive Observer (SAIO) for the state estimation of impulsive systems. The proposed observer is applicable to linear and nonlinear stochastic impulsive systems. In addition, the effect of parametric uncertainty is considered and unknown parameters of the system are estimated by suitable adaptation laws. Impulsive system theory, particularly stochastic Lyapunov-like function, is used to analyze the stability and convergence of the state estimations. The main advantages of the proposed observer are: 1) it gives continuous estimation from discrete time measurements of the system output, and 2) it is useful for state estimation when continuous measurements are impossible or expensive. Simulation results show the effectiveness of the proposed observer and we believe that it has many applications in control and estimation theories.

  3. An investigation of aerosol physical properties in Houston, Texas

    E-Print Network [OSTI]

    Gasparini, Roberto

    2002-01-01T23:59:59.000Z

    From June through October 2001, three Tandem Differential Mobility Analyzer (TDMA) systems were operated around Houston, Texas, to obtain a large, high-quality dataset in order to explore characteristics of aerosol size distributions...

  4. Aerosol source term in high pressure melt ejection

    SciTech Connect (OSTI)

    Brockmann, J.E.; Tarbell, W.W.

    1984-11-01T23:59:59.000Z

    Pressurized ejection of melt from a reactor pressure vessel has been identified as an important element of a severe reactor accident. Copious aerosol production is observed when thermitically generated melts pressurized with nitrogen or carbon dioxide to 1.3 to 17 MPa are ejected into an air atmosphere. Aerosol particle size distributions measured in the tests have modes of about 0.5, 5, and > 10 ..mu..m. Mechanisms leading to formation of these multimodal size distributions are suggested. This aerosol is a potentially important fission product source term that has not been considered in previous severe accident analyses.

  5. Aerosol Retrieval Using Remote-sensed Observations

    E-Print Network [OSTI]

    Wang, Yueqing

    2012-01-01T23:59:59.000Z

    David J. Diner, Wedad A. Abdou, Thomas P. Ackerman, KathleenDavid J. Diner, Wedad A. Abdou, Howard R. Gordon, Ralph A.

  6. Direct and semidirect aerosol effects of Southern African biomass burning aerosol

    SciTech Connect (OSTI)

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

    2011-06-21T23:59:59.000Z

    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.

  7. Aerosol behavior in a steam-air environment

    SciTech Connect (OSTI)

    Adams, R.E.; Tobias, M.L.; Petrykowski, J.C.

    1984-01-01T23:59:59.000Z

    The behavior of aerosols assumed to be characteristic of those generated during accident sequences and released into containment is being studied in the Nuclear Safety Pilot Plant (NSPP). Observation on the behavior of U/sub 3/O/sub 8/ aerosol, Fe/sub 2/O/sub 3/ aerosol, concrete aerosol, and various mixtures of these aerosols in a dry air environment and in a steam-air environment within the NSPP vessel are reported. Under dry conditions, the aerosols are agglomerated in the form of branched chains; the aerodynamic mass median diameter (AMMD) of the U/sub 3/O/sub 8/, Fe/sub 2/O/sub 3/ and mixed U/sub 3/O/sub 8/-Fe/sub 2/O/sub 3/ aerosols ranged between 1.5 and 3..mu..m while that of the concrete aerosol was about 1 ..mu..m. A steam-air environment, which would be present in LWR containment during and following an accident, causes the U/sub 3/O/sub 8/, the Fe/sub 2/O/sub 3/, and mixed U/sub 3/O/sub 8/-Fe/sub 2/O/sub 3/ aerosols to behave differently from that in a dry atmosphere; the primary effect is an enhanced rate of removal of the aerosol from the vessel atmosphere. Steam does not have a significant effect on the removal rate of a concrete aerosol. Electron microscopy showed the agglomerated U/sub 3/O/sub 8/, Fe/sub 2/O/sub 3/, and mixed U/sub 3/O/sub 8/-Fe/sub 2/O/sub 3/ aerosols to be in the form of spherical clumps of particles differing from the intermingled branched chains observed in the dry air tests; the AMMD was in the range of 1 to 2 ..mu..m. Steam had a lesser influence on the physical shape of the concrete aerosol with the shape being intermediate between branched chain and spherical clumps. 9 figures.

  8. Modeling aerosols and their interactions with shallow cumuli during the 2007 CHAPS field study

    SciTech Connect (OSTI)

    Shrivastava, ManishKumar B.; Berg, Larry K.; Fast, Jerome D.; Easter, Richard C.; Laskin, Alexander; Chapman, Elaine G.; Gustafson, William I.; Liu, Ying; Berkowitz, Carl M.

    2013-02-07T23:59:59.000Z

    The Weather Research and Forecasting model coupled with chemistry (WRF-Chem) is used to simulate relationships between aerosols and clouds in the vicinity of Oklahoma City during the June 2007 Cumulus Humilis Aerosol Processing Study (CHAPS). The regional scale simulation completed using 2 km horizontal grid spacing evaluates four important relationships between aerosols and shallow cumulus clouds observed during CHAPS. First, the model reproduces the trends of higher nitrate volume fractions in cloud droplet residuals compared to interstitial non-activated aerosols, as measured using the Aerosol Mass Spectrometer. Comparing simulations with cloud chemistry turned on and off, we show that nitric acid vapor uptake by cloud droplets explains the higher nitrate content of cloud droplet residuals. Second, as documented using an offline code, both aerosol water and other inorganics (OIN), which are related to dust and crustal emissions, significantly affect predicted aerosol optical properties. Reducing the OIN content of wet aerosols by 50% significantly improves agreement of model predictions with measurements of aerosol optical properties. Third, the simulated hygroscopicity of aerosols is too high as compared to their hygroscopicity derived from cloud condensation nuclei and particle size distribution measurements, indicating uncertainties associated with simulating size-dependent chemical composition and treatment of aerosol mixing state within the model. Fourth, the model reasonably represents the observations of the first aerosol indirect effect where pollutants in the vicinity of Oklahoma City increase cloud droplet number concentrations and decrease the droplet effective radius. While previous studies have often focused on cloud-aerosol interactions in stratiform and deep convective clouds, this study highlights the ability of regional-scale models to represent some of the important aspects of cloud-aerosol interactions associated with fields of short-lived shallow cumuli.

  9. Highly stable aerosol generator

    DOE Patents [OSTI]

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

    1981-11-03T23:59:59.000Z

    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.

  10. Geometrical Optics of Dense Aerosols

    SciTech Connect (OSTI)

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

    2013-04-24T23:59:59.000Z

    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. __________________________________________________

  11. OBSERVER DESIGN FOR NONLINEAR SYSTEMS BY USING INPUT-TO-STATE STABILITY

    E-Print Network [OSTI]

    Sontag, Eduardo

    OBSERVER DESIGN FOR NONLINEAR SYSTEMS BY USING INPUT-TO-STATE STABILITY A. Alessandri Abstract by solving LMI problems [18]. A. Alessandri is with the Institute of Intelligent Systems for Automation

  12. Surface aerosol radiative forcing derived from collocated ground-based radiometric

    E-Print Network [OSTI]

    Liou, K. N.

    Surface aerosol radiative forcing derived from collocated ground-based radiometric observations-Filter Rotating Shadowband Radiometer data match closely with those from the Cimel sun- photometer data for two of the sunphotometer to retrieve aerosol optical depths, a, along with observed surface flux data from field campaigns

  13. 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]

    Tsimpidi, A. P.

    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 ...

  14. Absorbing Aerosol Index (AAI) The residue method for the detection of aerosols

    E-Print Network [OSTI]

    Graaf, Martin de

    Absorbing Aerosol Index (AAI) The residue method for the detection of aerosols from space reflection and absorption Surface Rayleigh atmosphere #12;TOA Multiple scattering Multiple scattering Aerosol layer satellite Surface reflection and absorption Surface Rayleigh atmosphere Rayleigh atmophere Aerosol

  15. Electrostatics and radioactive aerosol behavior

    SciTech Connect (OSTI)

    Clement, C.F.

    1994-12-31T23:59:59.000Z

    Radioactive aerosols differ from their nonradioactive counterparts by their ability to charge themselves by emitting charged particles during the radioactive decay process. Evidence that electrostatics, including this charging process, can affect the transport of the aerosols was summarized previously. Charge distributions and the mean charge for a monodisperse radioactive aerosol have been considered in detail. The principal results of theory to calculate charge distributions on a aerosol with a size distribution, changes to Brownian coagulation rates for an aerosol in a reactor containment, and possible changes to aerosol deposition resulting from the charging will be presented. The main purpose of the work has been to improve calculations of aerosol behavior in reactor containments, but behavior in less ionizing environments will be affected more strongly, and some problems remain to be solved in performing reliable calculations.

  16. ARM - Field Campaign - Observations and Modeling of the Green...

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

    govCampaignsObservations and Modeling of the Green Ocean Amazon: CCN Activity of Aerosols Related Campaigns Observations and Modeling of the Green Ocean Amazon (GOAMAZON 2014)...

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

    SciTech Connect (OSTI)

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

    2008-06-19T23:59:59.000Z

    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.

  18. aerosols and climate : uncertainties

    E-Print Network [OSTI]

    contributes to creating a level playing field. (BC emissions tradeble like CO2 emissions?) OUTLINE #12;size. policy measures, is even more uncertain (emissions & their chemical fingerprint are uncertain (not just aerosol emissions, not just climate impacts) OUTLINE #12;- Standardization doesn't reduce

  19. Impulsive observer-based control for linear systems using irregularly sampled measurements

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Impulsive observer-based control for linear systems using irregularly sampled measurements Y linear state feedback controller and an impulsive observer to provide an estimate the non-measured states, which are subsequently fed back in the control algorithm. We consider linear systems that can

  20. A climate sensitivity estimate using Bayesian fusion of instrumental observations and an Earth System model

    E-Print Network [OSTI]

    sensitivity estimate using Bayesian fusion of instrumental observations and an Earth System model, J. Geophys System model Roman Olson,1 Ryan Sriver,1 Marlos Goes,2,3 Nathan M. Urban,4,5 H. Damon Matthews,6 MuraliA climate sensitivity estimate using Bayesian fusion of instrumental observations and an Earth

  1. A nonlinear observer to estimate unknown parameters during the synchronization of chaotic systems

    E-Print Network [OSTI]

    L. Torres

    2014-06-20T23:59:59.000Z

    This paper proposes an Extended-Kalman-Filter-like observer for parameter estimation during synchronization of chaotic systems. The exponential stability of the observer is guaranteed by a persistent excitation condition. This approach is shown to be suitable for various classical chaotic systems and several simulations are presented accordingly.

  2. Development and Demonstration of a Relocatable Ocean OSSE System: Optimizing Ocean Observations for Hurricane Forecast

    E-Print Network [OSTI]

    forecasts for individual storms and improved seasonal forecast of the ocean thermal energy availableDevelopment and Demonstration of a Relocatable Ocean OSSE System: Optimizing Ocean Observations in the Gulf of Mexico is being extended to provide NOAA the ability to evaluate new ocean observing systems

  3. 6, 43414373, 2006 Cloud-borne aerosol

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Discussions Impact of cloud-borne aerosol representation on aerosol direct and indirect effects S. J. Ghan of aerosols employ a variety of rep- resentations of such cloud-borne particles. Here we use a global aerosol- ulated aerosol, cloud and radiation fields to various approximations to the representa- tion of cloud

  4. Lead exposures and biological responses in military weapons systems: Aerosol characteristics and acute lead effects among US Army artillerymen: Final report

    SciTech Connect (OSTI)

    Bhattacharyya, M.H.; Stebbings, J.H.; Peterson, D.P.; Johnson, S.A.; Kumar, R.; Goun, B.D.; Janssen, I.; Trier, J.E.

    1993-03-01T23:59:59.000Z

    This study was to determine the concentration and chemical nature of lead (Pb) aerosols produced during the firing of artillery and to determine the exposures and biological responses of crew members exposed to lead aerosols during such firing. The concentrations of lead-containing aerosols at crew positions depended on wind conditions, with higher concentrations when firing into a head wind. Aerosol concentrations were highest in the muzzle blast zone. Concentrations of lead in the blood of crew members rose during the first 12 days of exposure to elevated airborne lead concentrations and then leveled off. There was no rapid decrease in blood lead concentrations after completion of firing. Small decreases in hematocrit and small increases in free erythrocyte porphyrin were correlated with increasing exposure to airborne lead. These changes were reversed by seven weeks after firing. Changes in nerve conduction velocity had borderline statistical significance to airborne lead exposure. In measuring nerve conduction velocity, differences in skin temperature must be taken into account.

  5. On the relationship between stratospheric aerosols and nitrogen dioxide

    SciTech Connect (OSTI)

    Mills, M.J.; Langford, A.O.; O'Leary, T.J.; Arpag, K.; Miller, H.L.; Proffitt, M.H.; Sanders, R.W.; Solomon, S. (Aeronomy Laboratory, NOAA, Boulder, CO (United States) Univ. of Colorado, Boulder (United States))

    1993-06-18T23:59:59.000Z

    The authors report measurements of stratospheric column abundances of nitrogen dioxide above the Colorado mountains during Jan, Feb, and Mar 1992, following the arrival of the aerosol loading injected by Mt. Pinatubo. The column abundance data was correlated with concurrent lidar measurements which provided vertical aerosol profiles at the same site. Chemical reactions within polar stratospheric clouds have been shown to play a major role in ozone chemistry in the polar regions, and one could ask whether such clouds at mid latitudes could play a similar role. The sulfur dioxide loading due to the volcanic eruption provides an abrupt increase in sulfuric acid aerosol surface area in mid latitude areas, providing a convenient test of this question. Column NO[sub 2] densities are observed to fall, but also found to saturate at a certain stratospheric aerosol density.

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

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

    Sivaraman, Chitra; Flynn, Connor

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

  7. Optical Properties of Secondary Organic Aerosols

    E-Print Network [OSTI]

    Kim, Hwajin

    2012-01-01T23:59:59.000Z

    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

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

    SciTech Connect (OSTI)

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

    2011-11-13T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    The HiRes Collaboration

    2005-12-15T23:59:59.000Z

    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.

  10. Nonequilibrium Atmospheric Secondary Organic Aerosol Formation...

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

    Aerosol Formation and Growth. Abstract: Airborne particles play a critical role in air quality, human health effects, visibility and climate. Secondary organic aerosols (SOA)...

  11. Sunlight Changes Aerosols in Clouds | EMSL

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

    Sunlight Changes Aerosols in Clouds Sunlight Changes Aerosols in Clouds Released: October 20, 2011 Scientists show how sunlight alters optical, chemical properties of atmospheric...

  12. Molecular Characterization of Biomass Burning Aerosols Using...

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

    Biomass Burning Aerosols Using High Resolution Mass Spectrometry. Molecular Characterization of Biomass Burning Aerosols Using High Resolution Mass Spectrometry. Abstract: Chemical...

  13. YEAR PROGRESS REPORT TITLE: Global Modeling of Tropospheric Aerosols and Their Contribution to Climate Variation

    E-Print Network [OSTI]

    as CCN would cool the climate system by about ­1.16 W m-2 , while carbonaceous aerosols from fossil fuel combustion acting alone may cool the system by about ­0.52 W m-2 (see Table 1). However, because-1- GACP 2nd YEAR PROGRESS REPORT TITLE: Global Modeling of Tropospheric Aerosols

  14. Pressure-flow reducer for aerosol focusing devices

    DOE Patents [OSTI]

    Gard, Eric (San Francisco, CA); Riot, Vincent (Oakland, CA); Coffee, Keith (Diablo Grande, CA); Woods, Bruce (Livermore, CA); Tobias, Herbert (Kensington, CA); Birch, Jim (Albany, CA); Weisgraber, Todd (Brentwood, CA)

    2008-04-22T23:59:59.000Z

    A pressure-flow reducer, and an aerosol focusing system incorporating such a pressure-flow reducer, for performing high-flow, atmosphere-pressure sampling while delivering a tightly focused particle beam in vacuum via an aerodynamic focusing lens stack. The pressure-flow reducer has an inlet nozzle for adjusting the sampling flow rate, a pressure-flow reduction region with a skimmer and pumping ports for reducing the pressure and flow to enable interfacing with low pressure, low flow aerosol focusing devices, and a relaxation chamber for slowing or stopping aerosol particles. In this manner, the pressure-flow reducer decouples pressure from flow, and enables aerosol sampling at atmospheric pressure and at rates greater than 1 liter per minute.

  15. Results from simulated upper-plenum aerosol transport tests

    SciTech Connect (OSTI)

    Wright, A.L.; Pattison, W.L.

    1986-01-01T23:59:59.000Z

    A series of eight aerosol transport experiments, designated as Aerosol Transport Tests (ATT) A101 through A108, has recently been completed at the Oak Ridge National Laboratory (ORNL). These tests provide a data base for validation of aerosol transport modeling used in the TRAP-MELT2 computer code (Jordan and Kuhlman, 1985), which was developed at Battelle Columbus Laboratories to calculate aerosol/fission-product transport in the reactor coolant system in postulated light-water reactor (LWR) core-melt accidents. Results from tests A103 and A104 have been summarized in a previous paper (Wright and Pattison, 1985a); the present paper discusses results from tests A105 through A108.

  16. Synthesis of pure, active, and fine NiFe?O? by aerosolization

    E-Print Network [OSTI]

    Yu, Hsuan-Fu

    1989-01-01T23:59:59.000Z

    and format of the Am. Ceram. Soc. This thesis deals with preparing nickel ferrite by the aerosol techniques to demonstrate the formation of double oxides in simple systems containing precursors that yield only one intermediate oxide phase. Ferrites... solution that contains Ni(II) and Fe(III) to form NiFez0~ is selected as the starting material for the aerosolization process. (b) to investigate the feasibility of the proposed aerosol technique by using an aqueous solution of corresponding salts...

  17. Emissions of crustal material in air quality forecast systems: Use of satellite observations

    E-Print Network [OSTI]

    Menut, Laurent

    Emissions of crustal material in air quality forecast systems: Use of satellite observations) Natural (dust, fires, volcanos) Meteorology: Transport, turbulence Clouds and radiation, precipitations Chemistry-transport model Gas and particles concentrations Use of model outputs: Analysis Direct: model vs

  18. A Search for Additional Planets in the Nasa Epoxi Observations of the Exoplanet System Gj 436

    E-Print Network [OSTI]

    Seager, Sara

    We present time series photometry of the M dwarf transiting exoplanet system GJ 436 obtained with the Extrasolar Planet Observation and Characterization (EPOCh) component of the NASA EPOXI mission. We conduct a search of ...

  19. EMPLOYMENT OPPORTUNITIES Hawaii Ocean Observing System (HiOOS) Employment Opportunities

    E-Print Network [OSTI]

    UHM EMPLOYMENT OPPORTUNITIES Hawaii Ocean Observing System (HiOOS) Employment Opportunities FIELD TECHNICIAN OPPORTUNITY: employment with possible development of a senior thesis project in GESCarlo, edecarlo@soest.hawaii.edu JOB REFERENCE NUMBER ON STUDENT EMPLOYMENT WEBSITE: none Student

  20. OBSERVING SYSTEM SIMULATION EXPERIMENTS ON THE OAH'U REGIONAL OCEAN MODEL

    E-Print Network [OSTI]

    Luther, Douglas S.

    Thermal Energy Conversion (OTEC) site off the south coast of Oah'u as well as the circulation of Mamala analyses of the observing systems were conducted at the outflow plume depth of a potential pilot Ocean

  1. EVALUATION OF ULTRASONIC SNOW DEPTH SENSORS FOR AUTOMATED SURFACE OBSERVING SYSTEMS (ASOS)

    E-Print Network [OSTI]

    i THESIS EVALUATION OF ULTRASONIC SNOW DEPTH SENSORS FOR AUTOMATED SURFACE OBSERVING SYSTEMS (ASOS PREPARED UNDER OUR SUPERVISION BY WENDY ANN BRAZENEC ENTITLED EVALUATION OF ULTRASONIC SNOW DEPTH SENSORS;iii ABSTRACT OF THESIS EVALUATION OF ULTRASONIC SNOW DEPTH SENSORS FOR AUTOMATED SURFACE OBSERVING

  2. Fine scale modeling of wintertime aerosol mass, number, and size distributions in central California

    E-Print Network [OSTI]

    Jacobson, Mark

    Fine scale modeling of wintertime aerosol mass, number, and size distributions in central with the observed PM number and size distributions (with an NMB of -13.9%), indicating the importance of coagulation scale modeling of wintertime aerosol mass, number, and size distributions in central California, J

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

    SciTech Connect (OSTI)

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

    2011-09-13T23:59:59.000Z

    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.

  4. 7, 37193761, 2007 Aerosol indirect

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    effects and is defined as the difference in the top-of-the-atmosphere net radiation be- tween present when either a statistical cloud cover scheme or a different aerosol emission inventory are employed. 1ACPD 7, 3719­3761, 2007 Aerosol indirect effects in ECHAM5-HAM U. Lohmann et al. Title Page

  5. 4, 75617614, 2004 Indirect aerosol

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    . While the cloud albedo enhance- ment (Twomey effect) of warm clouds received most attention so far, they can15 scatter, absorb and emit thermal radiation. Thirdly aerosol particles act as cloud con properties influenced by20 aerosols (e.g. semi-direct effect, suppression of convection). Clouds themselves

  6. 7, 1268712714, 2007 Aerosols' influence

    E-Print Network [OSTI]

    Boyer, Edmond

    in the polluted cloud is due to a more efficient collection process. 1 Introduction10 The effect of aerosol). Numerous studies have addressed the effect of aerosol on marine stratocumulus clouds, due to their key role in the global radiative energy. Marine stratocumuli, bounded by strong marine boundary layer inversion, have

  7. Clementine Observations of the Zodiacal Light and the Dust Content of the Inner Solar System

    E-Print Network [OSTI]

    Hahn, Joseph M.

    Clementine Observations of the Zodiacal Light and the Dust Content of the Inner Solar System Joseph Road 1, Houston, TX 77058 Bonnie Cooper Oceaneering Space Systems, 16665 Space Center Boulevard solar radii to the orbit of Venus. The averaged ecliptic surface brightness of the zodiacal light falls

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

    E-Print Network [OSTI]

    Carreira-Perpiñán, Miguel Á.

    OBSERVE: Occupancy-Based System for Efficient Reduction of HVAC Energy Varick L. Erickson, Miguel Á & control General Terms Algorithms, Machine Learning, Measurement Keywords Occupancy, HVAC, Ventilation for heating, ventilation, and air-conditioning (HVAC) systems[2]. Studies suggest that 15% to 25% of HVAC

  9. Progress Toward Observing Quantum Effects in an Optomechanical System in Cryogenics

    E-Print Network [OSTI]

    Harris, Jack

    , placed at 400 mK inside a 3 He fridge. The major goals of this research are: laser cooling the 261 kAbstract Progress Toward Observing Quantum Effects in an Optomechanical System in Cryogenics Cheng Yang 2011 Quantum optomechanical systems use radiation pressure of light to couple the optical field

  10. Aerosol Science and Technology, 42:115, 2008 Copyright c American Association for Aerosol Research

    E-Print Network [OSTI]

    Aerosol Science and Technology, 42:1­15, 2008 Copyright c American Association for Aerosol Research of a Fast-Response Aerosol Size Spectrometer Jason S. Olfert and Jian Wang Atmospheric Science Department by the mixing of the aerosol in the inlet of the instrument, which `smears' the detected aerosol over a range

  11. Ganges Valley Aerosol Experiment: Science and Operations Plan

    SciTech Connect (OSTI)

    Kotamarthi, VR

    2010-06-21T23:59:59.000Z

    The Ganges Valley region is one of the largest and most rapidly developing sections of the Indian subcontinent. The Ganges River, which provides the region with water needed for sustaining life, is fed primarily by snow and rainfall associated with Indian summer monsoons. Impacts of changes in precipitation patterns, temperature, and the flow of the snow-fed rivers can be immense. Recent satellite-based measurements have indicated that the upper Ganges Valley has some of the highest persistently observed aerosol optical depth values. The aerosol layer covers a vast region, extending across the Indo-Gangetic Plain to the Bay of Bengal during the winter and early spring of each year. The persistent winter fog in the region is already a cause of much concern, and several studies have been proposed to understand the economic, scientific, and societal dimensions of this problem. During the INDian Ocean EXperiment (INDOEX) field studies, aerosols from this region were shown to affect cloud formation and monsoon activity over the Indian Ocean. This is one of the few regions showing a trend toward increasing surface dimming and enhanced mid-tropospheric warming. Increasing air pollution over this region could modify the radiative balance through direct, indirect, and semi-indirect effects associated with aerosols. The consequences of aerosols and associated pollution for surface insolation over the Ganges Valley and monsoons, in particular, are not well understood. The proposed field study is designed for use of (1) the ARM Mobile Facility (AMF) to measure relevant radiative, cloud, convection, and aerosol optical characteristics over mainland India during an extended period of 9–12 months and (2) the G-1 aircraft and surface sites to measure relevant aerosol chemical, physical, and optical characteristics in the Ganges Valley during a period of 6–12 weeks. The aerosols in this region have complex sources, including burning of coal, biomass, and biofuels; automobile emissions; and dust. The extended AMF deployment will enable measurements under different regimes of the climate and aerosol abundance—in the wet monsoon period with low aerosol loading; in the dry, hot summer with aerosols dispersed throughout the atmospheric column; and in the cool, dry winter with aerosols confined mostly to the boundary later and mid-troposphere. Each regime, in addition, has its own distinct radiative and atmospheric dynamic drivers. The aircraft operational phase will assist in characterizing the aerosols at times when they have been observed to be at the highest concentrations. A number of agencies in India will collaborate with the proposed field study and provide support in terms of planning, aircraft measurements, and surface sites. The high concentration of aerosols in the upper Ganges Valley, together with hypotheses involving several possible mechanisms with direct impacts on the hydrologic cycle of the region, gives us a unique opportunity to generate data sets that will be useful both in understanding the processes at work and in providing answers regarding the effects of aerosols on climate in a region where the perturbation is the highest.

  12. Representing Cloud Processing of Aerosol in Numerical Models

    SciTech Connect (OSTI)

    Mechem, D.B.; Kogan, Y.L.

    2005-03-18T23:59:59.000Z

    The satellite imagery in Figure 1 provides dramatic examples of how aerosol influences the cloud field. Aerosol from ship exhaust can serve as nucleation centers in otherwise cloud-free regions, forming ship tracks (top image), or can enhance the reflectance/albedo in already cloudy regions. This image is a demonstration of the first indirect effect, in which changes in aerosol modulate cloud droplet radius and concentration, which influences albedo. It is thought that, through the effects it has on precipitation (drizzle), aerosol can also affect the structure and persistence of planetary boundary layer (PBL) clouds. Regions of cellular convection, or open pockets of cloudiness (bottom image) are thought to be remnants of strongly drizzling PBL clouds. Pockets of Open Cloudiness (POCs) (Stevens et al. 2005) or Albrecht's ''rifts'' are low cloud fraction regions characterized by anomalously low aerosol concentrations, implying they result from precipitation. These features may in fact be a demonstration of the second indirect effect. To accurately represent these clouds in numerical models, we have to treat the coupled cloud-aerosol system. We present the following series of mesoscale and large eddy simulation (LES) experiments to evaluate the important aspects of treating the coupled cloud-aerosol problem. 1. Drizzling and nondrizzling simulations demonstrate the effect of drizzle on a mesoscale forecast off the California coast. 2. LES experiments with explicit (bin) microphysics gauge the relative importance of the shape of the aerosol spectrum on the 3D dynamics and cloud structure. 3. Idealized mesoscale model simulations evaluate the relative roles of various processes, sources, and sinks.

  13. An Aerosol Condensation Model for Sulfur Trioxide

    SciTech Connect (OSTI)

    Grant, K E

    2008-02-07T23:59:59.000Z

    This document describes a model for condensation of sulfuric acid aerosol given an initial concentration and/or source of gaseous sulfur trioxide (e.g. fuming from oleum). The model includes the thermochemical effects on aerosol condensation and air parcel buoyancy. Condensation is assumed to occur heterogeneously onto a preexisting background aerosol distribution. The model development is both a revisiting of research initially presented at the Fall 2001 American Geophysical Union Meeting [1] and a further extension to provide new capabilities for current atmospheric dispersion modeling efforts [2]. Sulfuric acid is one of the most widely used of all industrial chemicals. In 1992, world consumption of sulfuric acid was 145 million metric tons, with 42.4 Mt (mega-tons) consumed in the United States [10]. In 2001, of 37.5 Mt consumed in the U.S., 74% went into producing phosphate fertilizers [11]. Another significant use is in mining industries. Lawuyi and Fingas [7] estimate that, in 1996, 68% of use was for fertilizers and 5.8% was for mining. They note that H{sub 2}SO{sub 4} use has been and should continue to be very stable. In the United States, the elimination of MTBE (methyl tertiary-butyl ether) and the use of ethanol for gasoline production are further increasing the demand for petroleum alkylate. Alkylate producers have a choice of either a hydrofluoric acid or sulfuric acid process. Both processes are widely used today. Concerns, however, over the safety or potential regulation of hydrofluoric acid are likely to result in most of the growth being for the sulfuric acid process, further increasing demand [11]. The implication of sulfuric acid being a pervasive industrial chemical is that transport is also pervasive. Often, this is in the form of oleum tankers, having around 30% free sulfur trioxide. Although sulfuric acid itself is not a volatile substance, fuming sulfuric acid (referred to as oleum) is [7], the volatile product being sulfur trioxide. Sulfate aerosols and mist may form in the atmosphere on tank rupture. From chemical spill data from 1990-1996, Lawuyi02 and Fingas [7] prioritize sulfuric acid as sixth most serious. During this period, they note 155 spills totaling 13 Mt, out of a supply volume of 3700 Mt. Lawuyi and Fingas [7] summarize information on three major sulfuric acid spills. On 12 February 1984, 93 tons of sulfuric acid were spilled when 14 railroad cars derailed near MacTier, Parry Sound, Ontario. On 13 December 1978, 51 railroad cars derailed near Springhill, Nova Scotia. One car, containing 93% sulfuric acid, ruptured, spilling nearly its entire contents. In July 1993, 20 to 50 tons of fuming sulfuric acid spilled at the General Chemical Corp. plant in Richmond, California, a major industrial center near San Francisco. The release occurred when oleum was being loaded into a nonfuming acid railroad tank car that contained only a rupture disk as a safety device. The tank car was overheated and this rupture disk blew. The resulting cloud of sulfuric acid drifted northeast with prevailing winds over a number of populated areas. More than 3,000 people subsequently sought medical attention for burning eyes, coughing, headaches, and nausea. Almost all were treated and released on the day of the spill. By the day after the release, another 5,000 people had sought medical attention. The spill forced the closure of five freeways in the region as well as some Bay Area Rapid Transit System stations. Apart from corrosive toxicity, there is the additional hazard that the reactions of sulfur trioxide and sulfuric acid vapors with water are extremely exothermic [10, 11]. While the vapors are intrinsically denser than air, there is thus the likelihood of strong, warming-induced buoyancy from reactions with ambient water vapor, water-containing aerosol droplets, and wet environmental surface. Nordin [12] relates just such an occurrence following the Richmond, CA spill, with the plume observed to rise to 300 m. For all practical purposes, sulfur trioxide was the constituent released from the heated tank

  14. The Nearby Supernova Factory Ozone + Aerosol + Rayleigh

    E-Print Network [OSTI]

    Rayleigh + Aerosol Extinction monitor filter Auxiliary Camera CCD Spectrograph picko ff mirror Umbra

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

    SciTech Connect (OSTI)

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

    2012-02-15T23:59:59.000Z

    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.

  16. Dynamical and Observational Constraints on Additional Planets in Highly Eccentric Planetary Systems

    E-Print Network [OSTI]

    Robert A. Wittenmyer; Michael Endl; William D. Cochran; Harold F. Levison

    2007-06-13T23:59:59.000Z

    Long time coverage and high radial velocity precision have allowed for the discovery of additional objects in known planetary systems. Many of the extrasolar planets detected have highly eccentric orbits, which raises the question of how likely those systems are to host additional planets. We investigate six systems which contain a very eccentric (e>0.6) planet: HD 3651, HD 37605, HD 45350, HD 80606, HD 89744, and 16 Cyg B. We present updated radial-velocity observations and orbital solutions, search for additional planets, and perform test particle simulations to find regions of dynamical stability. The dynamical simulations show that short-period planets could exist in the HD 45350 and 16 Cyg B systems, and we use the observational data to set tight detection limits, which rule out additional planets down to a few Neptune masses in the HD 3651, HD 45350, and 16 Cyg B systems.

  17. Testing a Coupled Global-limited-area Data Assimilation System Using Observations from the 2004 Pacific Typhoon Season

    E-Print Network [OSTI]

    Holt, Christina

    2012-10-19T23:59:59.000Z

    by the Statistical Spectral Interpolation, which was the operational data assimilation system of NCEP in 2004. The GFS Operational analysis assimilated a large number of satellite radiance observations in addition to the observations assimilated in our system. All...

  18. Electromagnetic scattering and absorption by aerosol agglomerates

    SciTech Connect (OSTI)

    Chen, Hsingyi.

    1989-01-01T23:59:59.000Z

    Calculation of scattering and absorption by smoke aerosols is required in many applications, including characterization of atmospheric aerosols, prediction of climatic impact of smoke, evaluation of smoke effectiveness in obscuration, calculation of heat transfer from flames, and evaluation of various scenarios of nuclear winter. In this dissertation two procedures were developed to accurately make these calculations utilizing realistic models of smoke agglomerates including oriented chains and fractal geometries. First the Iterative Extended Boundary Condition Method (IEBCM) was utilized to calculate the electromagnetic (EM) scattering and absorption of elongated aerosol particles. The computation efficiency and capability of IEBCM were improved by implementing the sectioning and the segmentation procedures. The sectioning procedure resulted in improving the computational efficiency and the segmentation method made it possible to make calculations for particles with aspect ratios as high as 250. The other procedure employed the Volume Integral Equation Formulation (VIEF) to compute the EM scattering and absorption by agglomerates of complex geometries. The validity of the procedure was checked first by comparing the obtained results with those obtained from the Mie solution for a spherical object and with the IEBCM for nonspherical objects. The comparison between results showed excellent agreement and hence validated the accuracy of the VIEF. The VIEF solution was then used to make calculations for five types of fractal agglomerates of smoke aerosol particles with fractal dimensions in the range from 1.7 to 1.9. The results obtained were compared with those based on the fractal theory recently published by Berry and Percival, and some differences were observed.

  19. Soft ionization of thermally evaporated hypergolic ionic liquid aerosols

    E-Print Network [OSTI]

    Koh, Christine J.

    2013-01-01T23:59:59.000Z

    + ][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

  20. Amine-Amine Exchange in Aminium-Methanesulfonate Aerosols. |...

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

    Amine-Amine Exchange in Aminium-Methanesulfonate Aerosols. Amine-Amine Exchange in Aminium-Methanesulfonate Aerosols. Abstract: Aerosol particles are ubiquitous in the atmosphere...

  1. Effect of Hydrophobic Primary Organic Aerosols on Secondary Organic...

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

    Hydrophobic Primary Organic Aerosols on Secondary Organic Aerosol Formation from Ozonolysis of ?-Pinene. Effect of Hydrophobic Primary Organic Aerosols on Secondary Organic...

  2. Mexico City Aerosol Analysis during MILAGRO using High Resolution...

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

    2: Mexico City Aerosol Analysis during MILAGRO using High Resolution Aerosol Mass Spectrometry at the Urban Supersite (T0). Part 2: Abstract: Submicron aerosol was analyzed during...

  3. Mexico City Aerosol Analysis during MILAGRO using High Resolution...

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

    1: Mexico City Aerosol Analysis during MILAGRO using High Resolution Aerosol Mass Spectrometry at the Urban Supersite (T0). Part 1: Abstract: Submicron aerosol was analyzed during...

  4. aerosol particles collected: Topics by E-print Network

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

    Saller 2002-05-07 6 Nanomaterials from Aerosols Aerosols are suspensions of liquid or solid particles in a gas. Aerosol particles Materials Science Websites Summary: being clouds...

  5. Aerosols and their influence on radiation partitioning and savanna productivity in northern Australia

    SciTech Connect (OSTI)

    Kanniah, K. D.; Beringer, J.; Tapper, N. J.; Long, Charles N.

    2010-05-01T23:59:59.000Z

    We investigated the effect of aerosols and clouds on the Net Ecosystem Productivity (NEP) of savannas in northern Australia using aerosol optical depth, clouds and radiation data from the Atmospheric Radiation Measurement (ARM) site in Darwin and carbon flux data measured from eddy covariance techniques from a site at Howard Springs, 35km southeast of Darwin. Generally we found that the concentration of aerosols in this region was relatively low than observed at other sites, therefore the proportion of diffuse radiation reaching the earths surface was only ~ 30%. As a result, we observed only a modest change in carbon uptake under aerosol laden skies and there was no significant difference for dry season Radiation Use Efficiency (RUE) between clear sky, aerosols or thin clouds. On the other hand thick clouds in the wet season produce much more diffuse radiation than aerosols or thin clouds and therefore the initial canopy quantum efficiency was seen to increase 45 and 2.5 times more than under thin clouds and aerosols respectively. The normalized carbon uptake under thick clouds is 57% and 50% higher than under aerosols and thin clouds respectively even though the total irradiance received under thick clouds was reduced 59% and 50% than under aerosols and thin clouds respectively. However, reduction in total irradiance decreases the mean absolute carbon uptake as much as 22% under heavy cloud cover compared to thin clouds or aerosols. Thus, any increase in aerosol concentration or cloud cover that can enhance the diffuse component may have large impacts on productivity in this region.

  6. ARM - Field Campaign - Observations and Modeling of the Green...

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

    Aerosol Gas chromatograph (SVTAG) Related Campaigns Observations and Modeling of the Green Ocean Amazon (GOAMAZON 2014) 2014.01.01, Martin, AMF Comments? We would love to hear...

  7. Role of ammonia chemistry and coarse mode aerosols in global climatological inorganic aerosol distributions

    E-Print Network [OSTI]

    Zender, Charles

    1 Role of ammonia chemistry and coarse mode aerosols in global climatological inorganic aerosol distributions Chao Luo1 , Charles S. Zender1 , Huisheng Bian2 , Swen Metzger3 Abstract We use an inorganic aerosol thermodynamic equilibrium model

  8. The Evolution of the Physicochemical Properties of Aerosols in the Atmosphere

    E-Print Network [OSTI]

    Tomlinson, Jason

    2011-02-22T23:59:59.000Z

    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...

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

    SciTech Connect (OSTI)

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

    2012-05-10T23:59:59.000Z

    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.

  10. Light water reactor aerosol containment experiment LA4 simulated by JERICHO and AEROSOLS-B2 codes

    SciTech Connect (OSTI)

    Passalacqua, R. [ENEA CRE Casaccia, Rome (Italy). Dept. Energia Settore Nucleare da Fissione; Tarabelli, D.; Renault, C. [CE Cadarache, St. Paul-lez-Durance (France). Inst. de Protection et de Surete Nucleaire

    1996-12-01T23:59:59.000Z

    Large-scale experiments show that whenever a loss of coolant accident occurs water pools are generated. Stratification of steam-saturated gas develops above growing water pools causing a different thermal hydraulics in the subcompartment where the water pool is located. Hereafter, the LWR Aerosols Containment Experiment (LACE) LA4 experiment, performed at the Hanford Engineering Development Laboratory, will be studied; this experiment exhibited a strong stratification, at all times, above a growing wade pool. JERICHO and AEROSOLS-B2 are part of the Ensemble de Systemes de Codes d`Analyse d`Accident des Reacteurs a Eau (ESCADRE) code system, a tool for evaluating the response of a nuclear plant to severe accidents. These two codes are used here to simulate respectively the thermal hydraulics and the associated aerosol behavior. Code results have shown that modeling large containment thermal hydraulics without taking into account the stratification phenomenon leads to large overpredictions of containment pressure and temperature. If the stratification, above the water pool, is modeled as a zone with a higher steam condensation rate and a higher thermal resistance (that is acting as a barrier to heat exchanges with the upper and larger compartment), ESCADRE predictions match experimental data quite well. The stratification region is believed to be able to affect aerosol behavior; aerosol settling is improved by steam condensation on particles and by diffusiophoresis and thermophoresis. In addition, the lower aerosol concentration throughout the stratification might cause a nonnegligible aerosol concentration gradient and consequently a driving force for the motion of smaller particles toward the pool.

  11. High latitude geomagnetically induced current events observed on very low frequency radio wave receiver systems

    E-Print Network [OSTI]

    Otago, University of

    High latitude geomagnetically induced current events observed on very low frequency radio wave induced current (GIC) in the Scottish power system in southern Scotland, during a storm event, and exhibit significantly different amplitude characteristics. Finally, we compared in detail the geomagnetic

  12. Faculty Observations: John Scofield An Energy-Monitoring System for Stanford

    E-Print Network [OSTI]

    Scofield, John H.

    Faculty Observations: John Scofield An Energy-Monitoring System for Stanford University's Leslie buildings use energy, and each year we conducted an energy audit of a local building, most often a house in town. We conducted energy audits of two Oberlin College buildings, the Wright Laboratory of Physics

  13. Observers for Nonlinear-Linear Cascade Systems Hvard Fjr Grip, Ali Saberi, and Tor A. Johansen

    E-Print Network [OSTI]

    Johansen, Tor Arne

    Observers for Nonlinear-Linear Cascade Systems Håvard Fjær Grip, Ali Saberi, and Tor A. Johansen been Håvard Fjær Grip and Ali Saberi are with the School of Electrical Engineering and Computer Science of Håvard Fjær Grip is supported by the Research Council of Norway. The work of Ali Saberi is partially

  14. HF radar in French Mediterranean Sea: an element of MOOSE Mediterranean Ocean Observing System on Environment

    E-Print Network [OSTI]

    Boyer, Edmond

    Sea in the context of climate change and anthropogenic pressure and to supply and maintain longHF radar in French Mediterranean Sea: an element of MOOSE Mediterranean Ocean Observing System , Pascal Guterman2 , Karim Bernardet2 1 Mediterranean Institute of Oceanography (MIO, UM 110, USTV

  15. AIRBORNE HIGH SPECTRAL RESOLUTION LIDAR MEASUREMENTS OF ATMOSPHERIC AEROSOLS

    E-Print Network [OSTI]

    the evolution and transport of pollution from Mexico City. The second major experiment was the Texas Air Quality Union 2007 Joint Assembly Acapulco, Mexico May 22-25, 2007 Environmental Sciences Department Research Observations (MILAGRO) /Megacity Aerosol Experiment in Mexico City (MAX

  16. Response to Comments on "Large VolcanicAerosolLoadintheStratosphere

    E-Print Network [OSTI]

    Robock, Alan

    , in addition, show that both wind trajectories and height-resolved profiles of sulfur dioxide indicate, it was overwhelmingly tropospheric. Additionally, the height-resolved sulfur dioxide profiles provide further convincing that "fully explains" the observed stratospheric aerosol load and distri- bution without any interaction

  17. Lubricating Oil Dominates Primary Organic Aerosol Emissions from Motor Vehicles

    E-Print Network [OSTI]

    Cohen, Ronald C.

    Lubricating Oil Dominates Primary Organic Aerosol Emissions from Motor Vehicles David R. Worton, United States *S Supporting Information ABSTRACT: Motor vehicles are major sources of primary organic characterization of motor vehicle POA emissions in a roadway tunnel with a mass closure of >60%. The observed POA

  18. What controls the recent changes in African mineral dust aerosol across the Atlantic?

    E-Print Network [OSTI]

    Ridley, David Andrew

    Dust from Africa strongly perturbs the radiative balance over the Atlantic, with emissions that are highly variable from year to year. We show that the aerosol optical depth (AOD) of dust over the mid-Atlantic observed by ...

  19. Climatic effects of 1950–2050 changes in US anthropogenic aerosols – Part 2: Climate response

    E-Print Network [OSTI]

    Leibensperger, Eric Michael

    We investigate the climate response to changing US anthropogenic aerosol sources over the 1950–2050 period by using the NASA GISS general circulation model (GCM) and comparing to observed US temperature trends. Time-dependent ...

  20. Effects of Sea-Salt Aerosols on Precipitation in Simulations of Shallow Cumulus

    E-Print Network [OSTI]

    Kogan, Yefim L.; Mechem, David B.; Choi, Kityan

    2012-02-01T23:59:59.000Z

    A suite of large-eddy simulations with size-resolving microphysical processes was performed in order to assess effects of sea-salt aerosols on precipitation process in trade cumulus. Simulations based on observations from ...

  1. E-Print Network 3.0 - aerosol generator model Sample Search Results

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

    S N E E T A L . 2002 American Meteorological Society Summary: by no more than 10% of the cooling caused by aerosols. 1. Introduction Observations and models highlight......

  2. 8, 68456901, 2008 Aerosol optical

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    of solar radiation by atmospheric aerosols is a key el- ement of the Earth's radiative energy balance, Germany 2 Helmholtz Center Munich, German Research Center for Environmental Health, Institute

  3. Aerosol penetration through transport lines

    E-Print Network [OSTI]

    Dileep, V.R.

    1996-01-01T23:59:59.000Z

    to predict aerosol penetration thrush shrouded probes and transition fitting('s. Experimnents were carried Out to validate the code. The experiments were carried out for different flow rates for a particle size of IO lam aerodynamic diameter (AD...

  4. Signatures of fractal clustering of aerosols advected under gravity

    E-Print Network [OSTI]

    Rafael Dias Vilela; Tamás Tél; Alessandro P. S. de Moura; Celso Grebogi

    2007-06-15T23:59:59.000Z

    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.

  5. EAS/CEE 6795 Atmospheric Aerosols Fall 2011

    E-Print Network [OSTI]

    Weber, Rodney

    EAS/CEE 6795 Atmospheric Aerosols Fall 2011 Mon Wed Fri ­ 11 concepts of aerosol physics with applications to atmospheric aerosols. Text Book: Hinds, Aerosol Technology: Properties, behavior and measurement of airborne particles

  6. CONSTRAINING THE PLANETARY SYSTEM OF FOMALHAUT USING HIGH-RESOLUTION ALMA OBSERVATIONS

    SciTech Connect (OSTI)

    Boley, A. C.; Payne, M. J.; Ford, E. B.; Shabram, M. [Department of Astronomy, University of Florida, 211 Bryant Space Science Center, Gainesville, FL 32611 (United States); Corder, S. [North American ALMA Science Center, National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903 (United States); Dent, W. R. F. [ALMA, Alonso de Cordova 3107, Vitacura, Santiago (Chile)

    2012-05-01T23:59:59.000Z

    The dynamical evolution of planetary systems leaves observable signatures in debris disks. Optical images trace micron-sized grains, which are strongly affected by stellar radiation and need not coincide with their parent body population. Observations of millimeter-sized grains accurately trace parent bodies, but previous images lack the resolution and sensitivity needed to characterize the ring's morphology. Here we present ALMA 350 GHz observations of the Fomalhaut debris ring. These observations demonstrate that the parent body population is 13-19 AU wide with a sharp inner and outer boundary. We discuss three possible origins for the ring and suggest that debris confined by shepherd planets is the most consistent with the ring's morphology.

  7. Method for producing monodisperse aerosols

    DOE Patents [OSTI]

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

    1990-01-01T23:59:59.000Z

    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.

  8. CARES: Carbonaceous Aerosol and Radiative Effects Study Operations Plan

    SciTech Connect (OSTI)

    Zaveri, RA; Shaw, WJ; Cziczo, DJ

    2010-07-12T23:59:59.000Z

    The CARES field campaign is motivated by the scientific issues described in the CARES Science Plan. The primary objectives of this field campaign are to investigate the evolution and aging of carbonaceous aerosols and their climate-affecting properties in the urban plume of Sacramento, California, a mid-size, mid-latitude city that is located upwind of a biogenic volatile organic compound (VOC) emission region. Our basic observational strategy is to make comprehensive gas, aerosol, and meteorological measurements upwind, within, and downwind of the urban area with the DOE G-1 aircraft and at strategically located ground sites so as to study the evolution of urban aerosols as they age and mix with biogenic SOA precursors. The NASA B-200 aircraft, equipped with the High Spectral Resolution Lidar (HSRL), digital camera, and the Research Scanning Polarimeter (RSP), will be flown in coordination with the G-1 to characterize the vertical and horizontal distribution of aerosols and aerosol optical properties, and to provide the vertical context for the G-1 and ground in situ measurements.

  9. Aerosols and Clouds: In Cahoots to Change Climate

    ScienceCinema (OSTI)

    Berg, Larry

    2014-06-02T23:59:59.000Z

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

  10. Speciation of Fe in ambient aerosol and cloudwater

    SciTech Connect (OSTI)

    Siefert, L. [California Institute of Technology, Pasadena, CA (United States)

    1996-08-15T23:59:59.000Z

    Atmospheric iron (Fe) is thought to play an important role in cloudwater chemistry (e.g., S(IV) oxidation, oxidant production, etc.), and is also an important source of Fe to certain regions of the worlds oceans where Fe is believed to be a rate-limiting nutrient for primary productivity. This thesis focuses on understanding the chemistry, speciation and abundance of Fe in cloudwater and aerosol in the troposphere, through observations of Fe speciation in the cloudwater and aerosol samples collected over the continental United States and the Arabian Sea. Different chemical species of atmospheric Fe were measured in aerosol and cloudwater samples to help assess the role of Fe in cloudwater chemistry.

  11. Aerosols and Clouds: In Cahoots to Change Climate

    SciTech Connect (OSTI)

    Berg, Larry

    2014-03-29T23:59:59.000Z

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

  12. State observers and Kalman filtering for high performance vibration isolation systems

    SciTech Connect (OSTI)

    Beker, M. G., E-mail: M.Beker@Nikhef.nl; Bertolini, A.; Hennes, E.; Rabeling, D. S. [National Institute for Subatomic Physics Nikhef, Science Park 105, 1098 XG Amsterdam (Netherlands)] [National Institute for Subatomic Physics Nikhef, Science Park 105, 1098 XG Amsterdam (Netherlands); Brand, J. F. J. van den; Bulten, H. J. [National Institute for Subatomic Physics Nikhef, Science Park 105, 1098 XG Amsterdam (Netherlands) [National Institute for Subatomic Physics Nikhef, Science Park 105, 1098 XG Amsterdam (Netherlands); VU University Amsterdam, de Boelelaan 1081, 1081 HV Amsterdam (Netherlands)

    2014-03-15T23:59:59.000Z

    There is a strong scientific case for the study of gravitational waves at or below the lower end of current detection bands. To take advantage of this scientific benefit, future generations of ground based gravitational wave detectors will need to expand the limit of their detection bands towards lower frequencies. Seismic motion presents a major challenge at these frequencies and vibration isolation systems will play a crucial role in achieving the desired low-frequency sensitivity. A compact vibration isolation system designed to isolate in-vacuum optical benches for Advanced Virgo will be introduced and measurements on this system are used to present its performance. All high performance isolation systems employ an active feedback control system to reduce the residual motion of their suspended payloads. The development of novel control schemes is needed to improve the performance beyond what is currently feasible. Here, we present a multi-channel feedback approach that is novel to the field. It utilizes a linear quadratic regulator in combination with a Kalman state observer and is shown to provide effective suppression of residual motion of the suspended payload. The application of state observer based feedback control for vibration isolation will be demonstrated with measurement results from the Advanced Virgo optical bench suspension system.

  13. Final Report: Process Models of the Equilibrium Size & State of Organic/Inorganic Aerosols for the Development of Large Scale Atmospheric Models & the Analysis of Field Data

    SciTech Connect (OSTI)

    Wexler, Anthony Stein [UC Davis] [UC Davis; Clegg, Simon Leslie [UC Davis] [UC Davis

    2013-10-26T23:59:59.000Z

    Our work addressed the following elements of the Call for Proposals: (i) “to improve the theoretical representation of aerosol processes studied in ASP laboratory or field studies”, (ii) “to enhance the incorporation of aerosol process information into modules suitable for large-scale or global atmospheric models”, and (iii) “provide systematic experimental validation of process model predictions ... using data from targeted laboratory and field experiments”. Achievements to the end of 2012 are described in four previous reports, and include: new models of densities and surface tensions of pure (single solute) and mixed aqueous solutions of typical aerosol composition under all atmospheric conditions (0 to 100% RH and T > 150 K); inclusion of these models into the widely used Extended Aerosol Inorganics model (E-AIM, http://www.aim.env.uea.ac.uk/aim/aim.php); the addition of vapor pressure calculators for organic compounds to the E-AIM website; the ability of include user-defined organic compounds and/or lumped surrogates in gas/aerosol partitioning calculations; the development of new equations to represent the properties of soluble aerosols over the entire concentration range (using methods based upon adsorption isotherms, and derived using statistical mechanics), including systems at close to zero RH. These results are described in publications 1-6 at the end of this report, and on the “News” page of the E-AIM website (http://www.aim.env.uea.ac.uk/aim/info/news.html). During 2012 and 2013 we have collaborated in a combined observation and lab-based study of the water uptake of the organic component of atmospheric aerosols (PI Gannet Hallar, of the Desert Research Institute). The aerosol samples were analyzed using several complementary techniques (GC/MS, FT-ICR MS, and ion chromatography) to produce a very complete organic “speciation” including both polar and non-polar compounds. Hygroscopic growth factors of the samples were measured, and we have just completed comparisons of the data with our process model predictions based upon the inorganic and organic composition of the samples.

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

    SciTech Connect (OSTI)

    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

    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.

  15. Aerosol Science and Technology, 43:641652, 2009 Copyright American Association for Aerosol Research

    E-Print Network [OSTI]

    Aerosol Science and Technology, 43:641­652, 2009 Copyright © American Association for Aerosol is the irreversibility of the hygroscopic growth fac- tor of aerosol particles. The instrument uses the hysteresis for ideal instrument performance in application to a test aerosol of fully deliquesce- able particles

  16. Aerosol Science and Technology, 43:799807, 2009 Copyright American Association for Aerosol Research

    E-Print Network [OSTI]

    Aerosol Science and Technology, 43:799­807, 2009 Copyright © American Association for Aerosol and Efflorescence of Potassium Salts Relevant to Biomass-Burning Aerosol Particles Evelyn J. Freney,1 Scot T. Martin mate- rial into the atmosphere. Such aerosol particles affect the climate in part because

  17. Aerosol Science and Technology, 47:9398, 2013 Copyright C American Association for Aerosol Research

    E-Print Network [OSTI]

    Huang, Jiaxing

    Aerosol Science and Technology, 47:93­98, 2013 Copyright C American Association for Aerosol of Pt-Nanoparticles-Laden Graphene Crumples by Aerosol Spray Pyrolysis and Evaluation of aqueous chloroplatinic acid (H2PtCl6) and graphene oxide (GO) sheets via aerosol spray pyrol- ysis (ASP

  18. Simulating aerosols using a chemical transport model with assimilation of satellite aerosol retrievals

    E-Print Network [OSTI]

    Zender, Charles

    Simulating aerosols using a chemical transport model with assimilation of satellite aerosol 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

  19. Aerosol Science and Technology, 46:12391245, 2012 Copyright C American Association for Aerosol Research

    E-Print Network [OSTI]

    Nizkorodov, Sergey

    Aerosol Science and Technology, 46:1239­1245, 2012 Copyright C American Association for Aerosol of Surfactants in Nanoparticles Produced by an Electrospray Aerosol Generator Amanda C. MacMillan,1 John B, USA Electrospray aerosol generators (EAGs) disperse conducting solutions into air, promptly neutralize

  20. Aerosol Science and Technology, 41:10891101, 2007 Copyright c American Association for Aerosol Research

    E-Print Network [OSTI]

    Aerosol Science and Technology, 41:1089­1101, 2007 Copyright c American Association for Aerosol Interferometric Aerosol Absorption Spectrometry Arthur Sedlacek and Jeonghoon Lee Brookhaven National Laboratory, Atmospheric Sciences, Upton, New York, USA Aerosol light absorption still remains a difficult quantity to mea

  1. Aerosol Science and Technology, 40:97106, 2006 Copyright c American Association for Aerosol Research

    E-Print Network [OSTI]

    Aerosol Science and Technology, 40:97­106, 2006 Copyright c American Association for Aerosol the aerosol particles, namely by vaporizing and condensing granular sodium chloride and by electrospraying materials are available for this article. Go to the publisher's online edition of Aerosol Science and Tech

  2. Aerosol Science and Technology, 46:937949, 2012 Copyright C American Association for Aerosol Research

    E-Print Network [OSTI]

    Aerosol Science and Technology, 46:937­949, 2012 Copyright C American Association for Aerosol Distributions following Condensational Growth in Continuous Flow Aerosol Reactors as Derived from Residence Time Distributions: Theoretical Development and Application to Secondary Organic Aerosol Mikinori Kuwata and Scot T

  3. Aerosol Science and Technology, 44:11401145, 2010 Copyright American Association for Aerosol Research

    E-Print Network [OSTI]

    Huang, Jiaxing

    Aerosol Science and Technology, 44:1140­1145, 2010 Copyright © American Association for Aerosol-Assembly of Nanoparticles in Evaporating Aerosol Droplets: Preparation of Nanoporous Pt/TiO2 Composite Particles Hee Dong, USA Nanoporous Pt/TiO2 micro-particles were synthesized via an aerosol assisted co-assembly (AACA

  4. Mercury capture by aerosol transformation in combustion environments. Appendix 5

    SciTech Connect (OSTI)

    NONE

    1997-02-01T23:59:59.000Z

    Aerosol transformation of elemental mercury by oxidizing mercury in the air is investigated in this study by varying temperature and residence time. The experimental results show that mercury oxidation is not important at the temperature range and time scale studied. The rate of mercury oxidation is too slow that the capture of mercury vapor by transforming it into mercury oxide in aerosol phase is not practical in real systems. Studies are needed for alternative approaches to capture mercury vapor such as the use of sorbent materials.

  5. Optical observations of Be/X-ray transient system KS 1947+300

    E-Print Network [OSTI]

    U. Kiziloglu; A. Baykal; N. Kiziloglu

    2006-08-05T23:59:59.000Z

    ROTSE-IIId observations of the Be/X-ray transient system KS 1947+300 obtained between September 2004 and December 2005 make it possible to study the correlation between optical and X-ray activity. The optical outburst of 0.1 mag was accompanied by an increase in X-ray flux in 2004 observations. Strong correlation between the optical and X-ray light curves suggests that neutron star directly accretes from the outflowing material of Be star. The nearly zero time lag between X-ray and optical light curves suggests a heating of the disk of Be star by X-rays. No optical brightening and X-ray enhancement was seen in 2005 observations. There is no indication of the orbital modulation in the optical light curve.

  6. Urban and land surface effects on the 30 July 2003 mesoscale convective system event observed in the southern Great Plains

    E-Print Network [OSTI]

    Niyogi, Dev

    Urban and land surface effects on the 30 July 2003 mesoscale convective system event observed/Atmosphere Mesoscale Prediction System (COAMPS 1 ) to investigate the impact of urban and land vegetation processes on the prediction of the mesoscale convective system (MCS) observed on 30 July 2003 in the vicinity of Oklahoma City

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

    SciTech Connect (OSTI)

    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

    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.

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

    E-Print Network [OSTI]

    Shields, Laura Grace

    2008-01-01T23:59:59.000Z

    detection efficiencies of aerosol time of flight masscomposition of ambient aerosol particles. Environmentalsize dependent response of aerosol counters, Atmospheric

  9. Hyperspectral Aerosol Optical Depths from TCAP Flights

    SciTech Connect (OSTI)

    Shinozuka, Yohei; Johnson, Roy R.; Flynn, Connor J.; Russell, P. B.; Schmid, Beat; Redemann, Jens; Dunagan, Stephen; Kluzek, Celine D.; Hubbe, John M.; Segal-Rosenheimer, Michal; Livingston, J. M.; Eck, T.; Wagener, Richard; Gregory, L.; Chand, Duli; Berg, Larry K.; Rogers, Ray; Ferrare, R. A.; Hair, John; Hostetler, Chris A.; Burton, S. P.

    2013-11-13T23:59:59.000Z

    4STAR (Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research), the world’s first hyperspectral airborne tracking sunphotometer, acquired aerosol optical depths (AOD) at 1 Hz during all July 2012 flights of the Two Column Aerosol Project (TCAP). Root-mean square differences from AERONET ground-based observations were 0.01 at wavelengths between 500-1020 nm, 0.02 at 380 and 1640 nm and 0.03 at 440 nm in four clear-sky fly-over events, and similar in ground side-by-side comparisons. Changes in the above-aircraft AOD across 3-km-deep spirals were typically consistent with integrals of coincident in situ (on DOE Gulfstream 1 with 4STAR) and lidar (on NASA B200) extinction measurements within 0.01, 0.03, 0.01, 0.02, 0.02, 0.02 at 355, 450, 532, 550, 700, 1064 nm, respectively, despite atmospheric variations and combined measurement uncertainties. Finer vertical differentials of the 4STAR measurements matched the in situ ambient extinction profile within 14% for one homogeneous column. For the AOD observed between 350-1660 nm, excluding strong water vapor and oxygen absorption bands, estimated uncertainties were ~0.01 and dominated by (then) unpredictable throughput changes, up to +/-0.8%, of the fiber optic rotary joint. The favorable intercomparisons herald 4STAR’s spatially-resolved high-frequency hyperspectral products as a reliable tool for climate studies and satellite validation.

  10. Observation of transient gain without population inversion in a laser-cooled rubidium lambda system

    E-Print Network [OSTI]

    S. R. de Echaniz; Andrew D. Greentree; A. V. Durrant; D. M. Segal; J. P. Marangos; J. A. Vaccaro

    2001-05-17T23:59:59.000Z

    We have observed clear Rabi oscillations of a weak probe in a strongly driven three-level lambda system in laser-cooled rubidium for the first time. When the coupling field is non-adiabatically switched on using a Pockels cell, transient probe gain without population inversion is obtained in the presence of uncoupled absorptions. Our results are supported by three-state computations.

  11. Observational determination of the time delays in gravitational lens system Q2237+030

    E-Print Network [OSTI]

    V. Vakulik; R. Schild; V. Dudinov; S. Nuritdinov; V. Tsvetkova; O. Burkhonov; T. Akhunov

    2005-09-19T23:59:59.000Z

    We present new brightness monitoring observations of the 4 components of gravitationally lensed system Q2237+0305, which show detection of an intrinsic quasar brightness fluctuation at a time of subdued microlensing activity, between June 27 and October 12, 2003. These data were used to determine the time delays between the arrivals of the four images. The measured delays are -6, 35, and 2 hours for images B, C and D relative to A, respectively, so they confirm that the long history of brightness monitoring has produced significant detection of microlensing. However the error bars associated with the delays, of order 2 days, are too large to discriminate between competing macro-imaging models. Moreover, our simulations show that for the amplitude of this intrinsic fluctuation and for photometric errors intrinsic to optical monitoring from our 1.5-m telescope or from the OGLE monitoring, a daily sampled brightness record cannot produce reliable lags for model discrimination. We use our simulations to devise a strategy for future delay determination with optical data. Nevertheless, we regard these first estimates to be significant, since they are the first direct measurements of time delays made for this system from ground-based observations in the visual wavelengths. Our results provide the most convincing confirmation of the gravitational-lens nature of Q2237+0305, and give observational justification to the extensive literature which attributes the quasar's previously observed brightness fluctuations to microlensing.

  12. ARM - Field Campaign - Observations and Modeling of the Green...

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

    proposed study will improve the understanding and representation in climate and Earth system models of clouds and aerosols as well as their interactions and coupling with the...

  13. The Arctic Lower Troposphere Observed Structure (ALTOS) Campaign

    SciTech Connect (OSTI)

    Verlinde, J

    2010-10-18T23:59:59.000Z

    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.

  14. Effect of Terrestrial and Marine Organic Aerosol on Regional and Global Climate: Model Development, Application, and Verification with Satellite Data

    SciTech Connect (OSTI)

    Meskhidze, Nicholas; Zhang, Yang; Kamykowski, Daniel

    2012-03-28T23:59:59.000Z

    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

  15. Particle size distribution of indoor aerosol sources

    SciTech Connect (OSTI)

    Shah, K.B.

    1990-10-24T23:59:59.000Z

    As concern about Indoor Air Quality (IAQ) has grown in recent years, it has become necessary to determine the nature of particles produced by different indoor aerosol sources and the typical concentration that these sources tend to produce. These data are important in predicting the dose of particles to people exposed to these sources and it will also enable us to take effective mitigation procedures. Further, it will also help in designing appropriate air cleaners. A new state of the art technique, DMPS (Differential Mobility Particle Sizer) System is used to determine the particle size distributions of a number of sources. This system employs the electrical mobility characteristics of these particles and is very effective in the 0.01--1.0 {mu}m size range. A modified system that can measure particle sizes in the lower size range down to 3 nm was also used. Experimental results for various aerosol sources is presented in the ensuing chapters. 37 refs., 20 figs., 2 tabs.

  16. 6, 42134249, 2006 Organic aerosols in

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    ACPD 6, 4213­4249, 2006 Organic aerosols in the Northeastern Pacific K. K. Crahan et al. Title Page Chemistry and Physics Discussions Organics in the Northeastern Pacific and their impacts on aerosol Organic aerosols in the Northeastern Pacific K. K. Crahan et al. Title Page Abstract Introduction

  17. 8, 7194, 2008 Sea salt aerosol

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    ACPD 8, 71­94, 2008 Sea salt aerosol refractive indices R. Irshad et al. Title Page Abstract Discussions Laboratory measurements of the optical properties of sea salt aerosol R. Irshad 1 , R. G. Grainger salt aerosol refractive indices R. Irshad et al. Title Page Abstract Introduction Conclusions

  18. 4, 20552088, 2004 Aerosol-ozone

    E-Print Network [OSTI]

    Boyer, Edmond

    ACPD 4, 2055­2088, 2004 Aerosol-ozone correlations during dust transport episodes P. Bonasoni et al and Physics Discussions Aerosol-ozone correlations during dust transport episodes P. Bonasoni1 , P.bonasoni@isac.cnr.it) 2055 #12;ACPD 4, 2055­2088, 2004 Aerosol-ozone correlations during dust transport episodes P. Bonasoni

  19. 6, 93519388, 2006 Aerosol-cloud

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    ACPD 6, 9351­9388, 2006 Aerosol-cloud interaction inferred from MODIS and models G. Myhre et al Chemistry and Physics Discussions Aerosol-cloud interaction inferred from MODIS satellite data and global 6, 9351­9388, 2006 Aerosol-cloud interaction inferred from MODIS and models G. Myhre et al. Title

  20. 5, 50075038, 2005 Aerosol effect on

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    and Physics Discussions Aerosol effect on the distribution of solar radiation over the clear-sky global oceansACPD 5, 5007­5038, 2005 Aerosol effect on solar radiation from MODIS L. A. Remer and Y. J. Kaufman the reflected sunlight by the aerosol over global oceans in cloud free conditions. The MODIS high spatial

  1. FY 2011 Third Quarter Report Estimate of Historical Aerosol Direct and Indirect Effects

    SciTech Connect (OSTI)

    Koch, D

    2011-06-22T23:59:59.000Z

    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.

  2. Aerosol source term in high-pressure-melt ejection. [PWR; BWR

    SciTech Connect (OSTI)

    Brockmann, J.E.; Tarbell, W.W.

    1983-01-01T23:59:59.000Z

    Pressurized ejection of melt from a reactor pressure vessel has been identified as an important element of a severe reactor accident. Copious aerosol production is observed when thermitically generated melts pressurized with nitrogen or carbon dioxide to 1.3 to 17 MPa are ejected into an air atmosphere. Aerosol particle size distributions measured in the tests have modes of about 0.5, 5, and > 10..mu..m. Mechanisms leading to formation of these multimodal size distributions are suggested. This aerosol is a potentially important fission product source term which has not been considered in previous severe accident analyses.

  3. Observable Consequences of Planet Formation Models in Systems with Close-in Terrestrial Planets

    E-Print Network [OSTI]

    Sean N. Raymond; Rory Barnes; Avi M. Mandell

    2007-11-13T23:59:59.000Z

    To date, two planetary systems have been discovered with close-in, terrestrial-mass planets (planet; 4) formation from material being shepherded by moving secular resonances during dispersal of the protoplanetary disk; 5) tidal circularization of eccentric terrestrial planets with close-in perihelion distances; and 6) photo-evaporative mass loss of a close-in giant planet. Models 1-4 have been validated in previous work. We show that tidal circularization can form hot Earths, but only for relatively massive planets (> 5 Earth masses) with very close-in perihelion distances (planets of less than about 70 Earth masses, photo-evaporation can remove the planet's envelope and leave behind the solid core on a Gyr timescale, but only for planets inside 0.025-0.05 AU. Using two quantities that are observable by current and upcoming missions, we show that these models each produce unique signatures, and can be observationally distinguished. These observables are the planetary system architecture (detectable with radial velocities, transits and transit-timing) and the bulk composition of transiting close-in terrestrial planets (measured by transits via the planet's radius).

  4. Real time infrared aerosol analyzer

    DOE Patents [OSTI]

    Johnson, Stanley A. (Countryside, IL); Reedy, Gerald T. (Bourbonnais, IL); Kumar, Romesh (Naperville, IL)

    1990-01-01T23:59:59.000Z

    Apparatus for analyzing aerosols in essentially real time includes a virtual impactor which separates coarse particles from fine and ultrafine particles in an aerosol sample. The coarse and ultrafine particles are captured in PTFE filters, and the fine particles impact onto an internal light reflection element. The composition and quantity of the particles on the PTFE filter and on the internal reflection element are measured by alternately passing infrared light through the filter and the internal light reflection element, and analyzing the light through infrared spectrophotometry to identify the particles in the sample.

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

    SciTech Connect (OSTI)

    UC Davis; Cappa, Christopher D.; Wilson, Kevin R.

    2010-10-28T23:59:59.000Z

    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.

  6. Temporal Variability of Aerosol Properties during TCAP: Impact on Radiative Forcing

    SciTech Connect (OSTI)

    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

    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 Energy’s (DOE’s) 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.

  7. REPRESENTING AEROSOL DYNAMICS AND PROPERTIES IN CHEMICAL TRANSPORT MODELS BY THE METHOD OF MOMENTS.

    SciTech Connect (OSTI)

    SCHWARTZ,S.E.; MCGRAW,R.; BENKOVITZ,C.M.; WRIGHT,D.L.

    2001-04-01T23:59:59.000Z

    Atmospheric aerosols, suspensions of solid or liquid particles, are an important multi-phase system. Aerosols scatter and absorb shortwave (solar) radiation, affecting climate (Charlson et al., 1992; Schwartz, 1996) and visibility; nucleate cloud droplet formation, modifying the reflectivity of clouds (Twomey et al., 1984; Schwartz and Slingo, 1996) as well as contributing to composition of cloudwater and to wet deposition (Seinfeld and Pandis, 1998); and affect human health through inhalation (NRC, 1998). Existing and prospective air quality regulations impose standards on concentrations of atmospheric aerosols to protect human health and welfare (EPA, 1998). Chemical transport and transformation models representing the loading and geographical distribution of aerosols and precursor gases are needed to permit development of effective and efficient strategies for meeting air quality standards, and for examining aerosol effects on climate retrospectively and prospectively for different emissions scenarios. Important aerosol properties and processes depend on their size distribution: light scattering, cloud nucleating properties, dry deposition, and penetration into airways of lungs. The evolution of the mass loading itself depends on particle size because of the size dependence of growth and removal processes. For these reasons it is increasingly recognized that chemical transport and transformation models must represent not just the mass loading of atmospheric particulate matter but also the aerosol microphysical properties and the evolution of these properties if aerosols are to be accurately represented in these models. If the size distribution of the aerosol is known, a given property can be evaluated as the integral of the appropriate kernel function over the size distribution. This has motivated the approach of determining aerosol size distribution, and of explicitly representing this distribution and its evolution in chemical transport models.

  8. Vapor scavenging by atmospheric aerosol particles

    SciTech Connect (OSTI)

    Andrews, E.

    1996-05-01T23:59:59.000Z

    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.

  9. A Physically Based Framework for Modelling the Organic Fractionation of Sea Spray Aerosol from Bubble Film Langmuir Equilibria

    SciTech Connect (OSTI)

    Burrows, Susannah M.; Ogunro, O.; Frossard, Amanda; Russell, Lynn M.; Rasch, Philip J.; Elliott, S.

    2014-12-19T23:59:59.000Z

    The presence of a large fraction of organic matter in primary sea spray aerosol (SSA) can strongly affect its cloud condensation nuclei activity and interactions with marine clouds. Global climate models require new parameterizations of the SSA composition in order to improve the representation of these processes. Existing proposals for such a parameterization use remotely-sensed chlorophyll-a concentrations as a proxy for the biogenic contribution to the aerosol. However, both observations and theoretical considerations suggest that existing relationships with chlorophyll-a, derived from observations at only a few locations, may not be representative for all ocean regions. We introduce a novel framework for parameterizing the fractionation of marine organic matter into SSA based on a competitive Langmuir adsorption equilibrium at bubble surfaces. Marine organic matter is partitioned into classes with differing molecular weights, surface excesses, and Langmuir adsorption parameters. The classes include a lipid-like mixture associated with labile dissolved organic carbon (DOC), a polysaccharide-like mixture associated primarily with semi-labile DOC, a protein-like mixture with concentrations intermediate between lipids and polysaccharides, a processed mixture associated with recalcitrant surface DOC, and a deep abyssal humic-like mixture. Box model calculations have been performed for several cases of organic adsorption to illustrate the underlying concepts. We then apply the framework to output from a global marine biogeochemistry model, by partitioning total dissolved organic carbon into several classes of macromolecule. Each class is represented by model compounds with physical and chemical properties based on existing laboratory data. This allows us to globally map the predicted organic mass fraction of the nascent submicron sea spray aerosol. Predicted relationships between chlorophyll-\\textit{a} and organic fraction are similar to existing empirical parameterizations, but can vary between biologically productive and non-productive regions, and seasonally within a given region. Major uncertainties include the bubble film thickness at bursting and the variability of organic surfactant activity in the ocean, which is poorly constrained. In addition, marine colloids and cooperative adsorption of polysaccharides may make important contributions to the aerosol, but are not included here. This organic fractionation framework is an initial step towards a closer linking of ocean biogeochemistry and aerosol chemical composition in Earth system models. Future work should focus on improving constraints on model parameters through new laboratory experiments or through empirical fitting to observed relationships in the real ocean and atmosphere, as well as on atmospheric implications of the variable composition of organic matter in sea spray.

  10. Daily Processing of Solar System Object Observations by Gaia UMR 6202 Cassiope, University of Nice-Sophia Antipolis, CNRS,

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    complex operations, devoted to obtain the best accuracies in the output. It will operate on data obtainedDaily Processing of Solar System Object Observations by Gaia Tanga, P. UMR 6202 Cassiopée to a selected event. For this reason, a pipeline performing fast processing of Gaia observations of Solar System

  11. Understanding and Improving CRM and GCM Simulations of Cloud Systems with ARM Observations

    SciTech Connect (OSTI)

    Wu, Xiaoqing

    2014-02-25T23:59:59.000Z

    The works supported by this ASR project lay the solid foundation for improving the parameterization of convection and clouds in the NCAR CCSM and the climate simulations. We have made a significant use of CRM simulations and ARM observations to produce thermodynamically and dynamically consistent multi-year cloud and radiative properties; improve the GCM simulations of convection, clouds and radiative heating rate and fluxes using the ARM observations and CRM simulations; and understand the seasonal and annual variation of cloud systems and their impacts on climate mean state and variability. We conducted multi-year simulations over the ARM SGP site using the CRM with multi-year ARM forcing data. The statistics of cloud and radiative properties from the long-term CRM simulations were compared and validated with the ARM measurements and value added products (VAP). We evaluated the multi-year climate simulations produced by the GCM with the modified convection scheme. We used multi-year ARM observations and CRM simulations to validate and further improve the trigger condition and revised closure assumption in NCAR GCM simulations that demonstrate the improvement of climate mean state and variability. We combined the improved convection scheme with the mosaic treatment of subgrid cloud distributions in the radiation scheme of the GCM. The mosaic treatment of cloud distributions has been implemented in the GCM with the original convection scheme and enables the use of more realistic cloud amounts as well as cloud water contents in producing net radiative fluxes closer to observations. A physics-based latent heat (LH) retrieval algorithm was developed by parameterizing the physical linkages of observed hydrometeor profiles of cloud and precipitation to the major processes related to the phase change of atmospheric water.

  12. Review of models applicable to accident aerosols

    SciTech Connect (OSTI)

    Glissmeyer, J.A.

    1983-07-01T23:59:59.000Z

    Estimations of potential airborne-particle releases are essential in safety assessments of nuclear-fuel facilities. This report is a review of aerosol behavior models that have potential applications for predicting aerosol characteristics in compartments containing accident-generated aerosol sources. Such characterization of the accident-generated aerosols is a necessary step toward estimating their eventual release in any accident scenario. Existing aerosol models can predict the size distribution, concentration, and composition of aerosols as they are acted on by ventilation, diffusion, gravity, coagulation, and other phenomena. Models developed in the fields of fluid mechanics, indoor air pollution, and nuclear-reactor accidents are reviewed with this nuclear fuel facility application in mind. The various capabilities of modeling aerosol behavior are tabulated and discussed, and recommendations are made for applying the models to problems of differing complexity.

  13. Size-resolved parameterization of primary organic carbon in fresh marine aerosols

    SciTech Connect (OSTI)

    Long, Michael S [ORNL; Keene, William C [ORNL; Erickson III, David J [ORNL

    2009-12-01T23:59:59.000Z

    Marine aerosols produced by the bursting of artificially generated bubbles in natural seawater are highly enriched (2 to 3 orders of magnitude based on bulk composition) in marine-derived organic carbon (OC). Production of size-resolved particulate OC was parameterized based on a Langmuir kinetics-type association of OC to bubble plumes in seawater and resulting aerosol as constrained by measurements of aerosol produced from highly productive and oligotrophic seawater. This novel approach is the first to account for the influence of adsorption on the size-resolved association between marine aerosols and OC. Production fluxes were simulated globally with an eight aerosol-size-bin version of the NCAR Community Atmosphere Model (CAM v3.5.07). Simulated number and inorganic sea-salt mass production fell within the range of published estimates based on observationally constrained parameterizations. Because the parameterization does not consider contributions from spume drops, the simulated global mass flux (1.5 x 10{sup 3} Tg y{sup -1}) is near the lower limit of published estimates. The simulated production of aerosol number (2.1 x 10{sup 6} cm{sup -2} s{sup -1}) and OC (49 Tg C y{sup -1}) fall near the upper limits of published estimates and suggest that primary marine aerosols may have greater influences on the physiochemical evolution of the troposphere, radiative transfer and climate, and associated feedbacks on the surface ocean than suggested by previous model studies.

  14. Analysis of fluidized beds for the simultaneous aerosol separation and heat recovery

    SciTech Connect (OSTI)

    El-Halwagi, M.M. [Auburn Univ., AL (United States)

    1993-01-01T23:59:59.000Z

    A mathematical model is developed to describe the performance of fluidized beds for the simultaneous heat recovery and aerosol separation. This new concept is analyzed in light of the various transport processes taking place within the bed. A two-phase model is developed for the system in which heat and aerosol particles are transferred from the bubble phase to the emulsion phase. In addition to aerosol separation via diffusion, interception, impaction and electrostatic precipitation, thermophoretic collection is also analyzed. The results indicate that high thermal and separation efficiencies can be obtained.

  15. 7, 71717233, 2007 Aerosol absorption

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    black carbon refractive indices, new cloud radiative properties considering the effect of aerosol absorption and radiative forcing. The effect of the usage of more accurate effective medium approximations radiative properties re- sults in a small global annual-mean all-sky absorption of 0.05 W m-2 and a positive

  16. Observational Properties of Type Ib/c Supernova Progenitors in Binary Systems

    E-Print Network [OSTI]

    Kim, Hyun-Jeong; Koo, Bon-Chul

    2015-01-01T23:59:59.000Z

    In several recent observational studies on Type Ib/c supernovae (SNe Ib/c), the inferred ejecta masses have a peak value of 2.0 -- 4.0 $M_\\odot$, in favor of the binary scenario for their progenitors rather than the Wolf-Rayet star scenario. To investigate the observational properties of relatively low-mass helium stars in binary systems as SN Ib/c progenitors, we constructed atmospheric models with the non-LTE radiative transfer code CMFGEN, using binary star evolution models. We find that these helium stars can be characterized by relatively narrow helium emission lines if the mass-loss rate during the final evolutionary phase is significantly enhanced as implied by many SN Ib/c observations. The optical brightness of helium star progenitors can be meaningfully enhanced with a strong wind for $M \\gtrsim 4.4 M_\\odot$, but hardly affected or slightly weakened for relatively low-mass of $\\sim 3.0 M_\\odot$, compared to the simple estimate using blackbody approximation. We further confirm the previous suggestion...

  17. Heating and Dynamics of Two Flare Loop Systems Observed by AIA and EIS

    E-Print Network [OSTI]

    Li, Y; Ding, M D

    2013-01-01T23:59:59.000Z

    We investigate heating and evolution of flare loops in a C4.7 two-ribbon flare on 2011 February 13. From SDO/AIA imaging observations, we can identify two sets of loops. Hinode/EIS spectroscopic observations reveal blueshifts at the feet of both sets of loops. The evolution and dynamics of the two sets are quite different. The first set of loops exhibits blueshifts for about 25 minutes followed by redshifts, while the second set shows stronger blueshifts, which are maintained for about one hour. The UV 1600 observation by AIA also shows that the feet of the second set of loops brighten twice. These suggest that continuous heating may be present in the second set of loops. We use spatially resolved UV light curves to infer heating rates in the few tens of individual loops comprising the two loop systems. With these heating rates, we then compute plasma evolution in these loops with the "enthalpy-based thermal evolution of loops" (EBTEL) model. The results show that, for the first set of loops, the synthetic EU...

  18. Detection of UV-absorbing aerosols using GOME and SCIAMACHY

    E-Print Network [OSTI]

    Graaf, Martin de

    Detection of UV-absorbing aerosols using GOME and SCIAMACHY Martin de Graaf KNMI #12; Outline · The Absorbing Aerosol Index: some theory · Detection of biomass burning aerosols and desert dust. -no clouds -no scattering aerosols Absorbing Aerosol Index AAI Algorithm LUT #12;GOME & SCIAMACHY

  19. DO AEROSOLS CHANGE CLOUD COVER AND AFFECT CLIMATE?

    E-Print Network [OSTI]

    Schwartz, Stephen E.

    BALANCE Global and annual average energy fluxes in watts per square meter Schwartz, 1996, modified from;AEROSOL INFLUENCES ON CLIMATE AND CLIMATE CHANGE #12;DMS #12;AEROSOL IN MEXICO CITY BASIN #12;AEROSOL IN MEXICO CITY BASIN Light scattering by aerosols decreases absorption of solar radiation. #12;AEROSOLS

  20. Inorganic aerosols responses to emission changes in Yangtze River Delta, China

    SciTech Connect (OSTI)

    Dong, Xinyi; Li, Juan; Fu, Joshua S.; Gao, Yang; Huang, Kan; Zhuang, Guoshun

    2014-05-15T23:59:59.000Z

    China announced the Chinese National Ambient Air Quality standards (CH-NAAQS) on Feb. 29th, 2012, and PM2.5 is for the very first time included in the standards as a criteria pollutant. In order to probe into PM2.5 pollution over Yangtze River Delta, which is one of the major urban clusters hosting more than 80 million people in China, the integrated MM5/CMAQ modeling system is applied for a full year simulation to examine the PM2.5 concentration and seasonality, and also the inorganic aerosols responses to precursor emission changes. Both simulation and observation demonstrated that, inorganic aerosols have substantial contributions to PM2.5 over YRD, ranging from 37.1% in November to 52.8% in May. Nocturnal production of nitrate (NO3-) through heterogeneous hydrolysis of N2O5 was found significantly contribute to high NO3-concentration throughout the year. We also found that in winter NO3- was even increased under nitrogen oxides (NOx) emission reduction due to higher production of N2O5 from the excessive ozone (O3) introduced by attenuated titration, which further lead to increase of ammonium (NH4+) and sulfate (SO42-), while other seasons showed decrease response of NO3-. Sensitivity responses of NO3- under anthropogenic VOC emission reduction was examined and demonstrated that in urban areas over YRD, NO3- formation was actually VOC sensitive due to the O3-involved nighttime chemistry of N2O5, while a reduction of NOx emission may have counter-intuitive effect by increasing concentrations of inorganic aerosols.

  1. SO[subscript 2] photolysis as a source for sulfur mass-independent isotope signatures in stratospehric aerosols

    E-Print Network [OSTI]

    Jiang, B.

    Signatures of sulfur isotope mass-independent fractionation (S-MIF) have been observed in stratospheric sulfate aerosols deposited in polar ice. The S-MIF signatures are thought to be associated with stratospheric ...

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

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

    Meskhidze, Nicholas; Nenes, Athanasios

    2010-01-01T23:59:59.000Z

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

  3. Aerosol cluster impact and break-up : model and implementation.

    SciTech Connect (OSTI)

    Lechman, Jeremy B.

    2010-10-01T23:59:59.000Z

    In this report a model for simulating aerosol cluster impact with rigid walls is presented. The model is based on JKR adhesion theory and is implemented as an enhancement to the granular (DEM) package within the LAMMPS code. The theory behind the model is outlined and preliminary results are shown. Modeling the interactions of small particles is relevant to a number of applications (e.g., soils, powders, colloidal suspensions, etc.). Modeling the behavior of aerosol particles during agglomeration and cluster dynamics upon impact with a wall is of particular interest. In this report we describe preliminary efforts to develop and implement physical models for aerosol particle interactions. Future work will consist of deploying these models to simulate aerosol cluster behavior upon impact with a rigid wall for the purpose of developing relationships for impact speed and probability of stick/bounce/break-up as well as to assess the distribution of cluster sizes if break-up occurs. These relationships will be developed consistent with the need for inputs into system-level codes. Section 2 gives background and details on the physical model as well as implementations issues. Section 3 presents some preliminary results which lead to discussion in Section 4 of future plans.

  4. Low-temperature Bessel beam trap for single submicrometer aerosol particle studies

    SciTech Connect (OSTI)

    Lu, Jessica W.; Chasovskikh, Egor; Stapfer, David [Laboratory of Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, CH-8093 Zürich (Switzerland); Isenor, Merrill; Signorell, Ruth [Laboratory of Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, CH-8093 Zürich (Switzerland); Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1 (Canada)

    2014-09-01T23:59:59.000Z

    We report on a new instrument for single aerosol particle studies at low temperatures that combines an optical trap consisting of two counter-propagating Bessel beams (CPBBs) and temperature control down to 223 K (?50?°C). The apparatus is capable of capturing and stably trapping individual submicrometer- to micrometer-sized aerosol particles for up to several hours. First results from studies of hexadecane, dodecane, and water aerosols reveal that we can trap and freeze supercooled droplets ranging in size from ?450 nm to 5500 nm (radius). We have conducted homogeneous and heterogeneous freezing experiments, freezing-melting cycles, and evaporation studies. To our knowledge, this is the first reported observation of the freezing process for levitated single submicrometer-sized droplets in air using optical trapping techniques. These results show that a temperature-controlled CPBB trap is an attractive new method for studying phase transitions of individual submicrometer aerosol particles.

  5. A Saturn Ring Observer Mission Using Multi-Mission Radioisotope Power Systems

    SciTech Connect (OSTI)

    Abelson, Robert D.; Spilker, Thomas R.; Shirley, James H. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Mail Stop 301-445W, Pasadena, CA 91109-8099 (United States)

    2006-01-20T23:59:59.000Z

    Saturn remains one of the most fascinating planets within the solar system. To better understand the complex ring structure of this planet, a conceptual Saturn Ring Observer (SRO) mission is presented that would spend one year in close proximity to Saturn's A and B rings, and perform detailed observations and measurements of the ring particles and electric and magnetic fields. The primary objective of the mission would be to understand ring dynamics, including the microphysics of individual particles and small scale (meters to a few kilometers) phenomena such as particle agglomeration behavior. This would be accomplished by multispectral imaging of the rings at multiple key locations within the A and B rings, and by ring-particle imaging at an unprecedented resolution of 0.5 cm/pixel. The SRO spacecraft would use a Venus-Earth-Earth-Jupiter Gravity Assist (VEEJGA) and be aerocaptured into Saturn orbit using an advanced aeroshell design to minimize propellant mass. Once in orbit, the SRO would stand off from the ring plane 1 to 1.4 km using chemical thrusters to provide short propulsive maneuvers four times per revolution, effectively causing the SRO vehicle to 'hop' above the ring plane. The conceptual SRO spacecraft would be enabled by the use of a new generation of multi-mission Radioisotope Power Systems (RPSs) currently being developed by NASA and DOE. These RPSs include the Multi-Mission Radioisotope Thermoelectric Generator (MMRTG) and Stirling Radioisotope Generator (SRG). The RPSs would generate all necessary electrical power ({>=}330 We at beginning of life) during the 10-year cruise and 1-year science mission ({approx}11 years total). The RPS heat would be used to maintain the vehicle's operating and survival temperatures, minimizing the need for electrical heaters. Such a mission could potentially launch in the 2015-2020 timeframe, with operations at Saturn commencing in approximately 2030.

  6. High-speed, energy-resolved, STJ observations of the AM Her system V2301 Oph

    E-Print Network [OSTI]

    A. P. Reynolds; G. Ramsay; J. H. J. de Bruijne; M. A. C. Perryman; M. Cropper; C. M. Bridge; A. Peacock

    2005-02-02T23:59:59.000Z

    We present high time-resolution optical energy-resolved photometry of the eclipsing cataclysmic variable V2301 Oph made using the ESA S-Cam detector, an array of photon counting super-conducting tunnel junction (STJ) devices with intrinsic energy resolution. Three eclipses were observed, revealing considerable variation in the eclipse shape, particularly during ingress. The eclipse shape is shown to be understood in terms of AM Her accretion via a bright stream, with very little contribution from the white dwarf photosphere and/or hotspot. About two thirds of the eclipsed light arises in the threading region. Variation in the extent of the threading region can account for most of the variations observed between cycles. Spectral fits to the data reveal a 10,000K blackbody continuum with strong, time-varying emission lines of hydrogen and helium. This is the first time that stellar emission lines have been detected in the optical band using a non-dispersive photon-counting system.

  7. Intercomparison of 14C Analysis of Carbonaceous Aerosols: Exercise 2009

    E-Print Network [OSTI]

    2013-01-01T23:59:59.000Z

    analysis of carbonaceous aerosols: recent developments.Source apportionment of aerosols by 14 C measurements inAnalysis of Carbonaceous Aerosols Table 2a 14 C(TC) results

  8. Enhanced photolysis in aerosols: evidence for important surface effects.

    E-Print Network [OSTI]

    Nissenson, Paul; Knox, Christopher J H; Finlayson-Pitts, Barbara J; Phillips, Leon F; Dabdub, Donald

    2006-01-01T23:59:59.000Z

    irradiated for 30 s in the aerosol phase, (b) Mo(CO) 6 in 1-irradiation for both aerosols and the bulk-liquid solution.Enhanced photolysis in aerosols: evidence for important

  9. Remote sensing of terrestrial tropospheric aerosols from aircraft and satellites

    E-Print Network [OSTI]

    Remote sensing of terrestrial tropospheric aerosols from aircraft and satellites M I Mishchenko1 instruments suitable for aerosol remote sensing and give examples of aerosol retrievals obtained forcing directly by absorbing and reflecting sunlight, thereby cooling or heating the atmosphere

  10. Influence of steam on the behavior of U/sub 3/O/sub 8/ aerosols. [PWR; BWR

    SciTech Connect (OSTI)

    Adams, R.E.; Tobias, M.L.; Kress, T.S.

    1982-01-01T23:59:59.000Z

    A project is being conducted in the Nuclear Safety Pilot Plant (NSPP), located at the Oak Ridge National Laboratory (ORNL), to study the behavior of aerosols assumed to be generated during LWR reactor accident sequences and released into containment. This project, which is part of the ORNL Aerosol Release and Transport (ART) Program, is sponsored by the Nuclear Regulatory Commission and its purpose is to provide experimental qualification for LWR aerosol behavioral codes being developed independently by other NRC-sponsored programs. The program plan for the NSPP aerosol project provides for the study of the behavior of LWR accident aerosols emanating from fuel, reactor core structural materials, and from concrete-molten metal reactions. The behavior of each of these aerosols is being studied individually to establish their characteristics; future experiments will involve mixtures of these aerosols to establish their interaction and collective behavior within containment. The purpose of this paper is to document observations illustrating the influence that steam has on the behavior of U/sub 3/O/sub 8/ aerosols within the NSPP vessel.

  11. DEVELOPMENT OF A COASTAL MARGIN OBSERVATION AND ASSESSMENT SYSTEM (CMOAS) TO CAPTURE THE EPISODIC EVENTS IN A SHALLOW BAY

    E-Print Network [OSTI]

    Islam, Mohammad S.

    2010-07-14T23:59:59.000Z

    for the implementation of observational systems in other dynamic ecosystems for characterizing and predicting other episodic events such as harmful algal blooms, accidental oil spills, sediment resuspension events, etc. State-of-the-art sensor technologies are involved...

  12. Potential Soil Moisture Products from the Aquarius Radiometer and Scatterometer Using an Observing System Simulation Experiment

    SciTech Connect (OSTI)

    Luo, Yan [I.M. Systems Group at NOAA/NCEP/EMC; Feng, Xia [George Mason University; Houser, Paul [George Mason University; Anantharaj, Valentine G [ORNL; Fan, Xingang [Western Kentucky University, Bowling Green; De Lannoy, Gabrielle [Ghent University, Belgium; Zhan, Xiwu [NOAA/NESDIS Center for Satellite Applications and Research; Dabbiru, Lalitha [Mississippi State University (MSU)

    2013-01-01T23:59:59.000Z

    Using an observing system simulation experiment (OSSE), we investigate the potential soil moisture retrieval capability of the National Aeronautics and Space Administration (NASA) Aquarius radiometer (L-band 1.413 GHz) and scatterometer (L-band, 1.260 GHz). We estimate potential errors in soil moisture retrievals and identify the sources that could cause those errors. The OSSE system includes (i) a land surface model in the NASA Land Information System, (ii) a radiative transfer and backscatter model, (iii) a realistic orbital sampling model, and (iv) an inverse soil moisture retrieval model. We execute the OSSE over a 1000 2200 km2 region in the central United States, including the Red and Arkansas river basins. Spatial distributions of soil moisture retrieved from the radiometer and scatterometer are close to the synthetic truth. High root mean square errors (RMSEs) of radiometer retrievals are found over the heavily vegetated regions, while large RMSEs of scatterometer retrievals are scattered over the entire domain. The temporal variations of soil moisture are realistically captured over a sparely vegetated region with correlations 0.98 and 0.63, and RMSEs 1.28% and 8.23% vol/vol for radiometer and scatterometer, respectively. Over the densely vegetated region, soil moisture exhibits larger temporal variation than the truth, leading to correlation 0.70 and 0.67, respectively, and RMSEs 9.49% and 6.09% vol/vol respectively. The domain-averaged correlations and RMSEs suggest that radiometer is more accurate than scatterometer in retrieving soil moisture. The analysis also demonstrates that the accuracy of the retrieved soil moisture is affected by vegetation coverage and spatial aggregation.

  13. Molecular Characterization of Organic Aerosols Using Nanospray...

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

    in OA, which is important for understanding chemical aging phenomena. Citation: Roach PJ, J Laskin, and A Laskin.2010."Molecular Characterization of Organic Aerosols Using...

  14. Researchers Model Impact of Aerosols Over California

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

    Impact of Aerosols Over California Research may clarify the effectiveness of regional pollution controls May 28, 2013 | Tags: Climate Research, Hopper Contact: Linda Vu,...

  15. Photolytic processing of secondary organic aerosols dissolved...

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

    processing of secondary organic aerosols dissolved in cloud droplets. Abstract: The effect of UV irradiation on the molecular composition of aqueous extracts of secondary...

  16. IEEE TRANSACTIONS ON POWER SYSTEMS, VOL. 22, NO. 4, NOVEMBER 2007 1881 Analysis of Tap-Induced Oscillations Observed

    E-Print Network [OSTI]

    Hiskens, Ian A.

    analysis, tap-changing transformers, voltage oscillations. I. INTRODUCTION ANUMBER of years ago, voltage-Induced Oscillations Observed in an Electrical Distribution System Vaibhav Donde, Member, IEEE, and Ian A. Hiskens, Fellow, IEEE Abstract--Slow oscillations, with a period of around 15 min, were observed in an 11-k

  17. EMSP Final Report: Electrically Driven Technologies for Radioactive Aerosol Abatement

    SciTech Connect (OSTI)

    DePaoli, D.W.

    2003-01-22T23:59:59.000Z

    The purpose of this research project was to develop an improved understanding of how electrically driven processes, including electrocoalescence, acoustic agglomeration, and electric filtration, may be employed to efficiently treat problems caused by the formation of aerosols during DOE waste treatment operations. The production of aerosols during treatment and retrieval operations in radioactive waste tanks and during thermal treatment operations such as calcination presents a significant problem of cost, worker exposure, potential for release, and increased waste volume. There was anecdotal evidence in the literature that acoustic agglomeration and electrical coalescence could be used together to change the size distribution of aerosol particles in such a way as to promote easier filtration and less frequent maintenance of filtration systems. As such, those electrically driven technologies could potentially be used as remote technologies for improved treatment; however, existing theoretical models are not suitable for prediction and design. To investigate the physics of such systems, and also to prototype a system for such processes, a collaborative project was undertaken between Oak Ridge National Laboratory (ORNL) and the University of Texas at Austin (UT). ORNL was responsible for the larger-scale prototyping portion of the project, while UT was primarily responsible for the detailed physics in smaller scale unit reactors. It was found that both electrical coalescence and acoustic agglomeration do in fact increase the rate of aggregation of aerosols. Electrical coalescence requires significantly less input power than acoustic agglomeration, but it is much less effective in its ability to aggregate/coalesce aerosols. The larger-scale prototype showed qualitatively similar results as the unit reactor tests, but presented more difficulty in interpretation of the results because of the complex multi-physics coupling that necessarily occur in all larger-scale system tests. An additional finding from this work is that low-amplitude oscillation may provide an alternative, non-invasive, non-contact means of controlling settling and/or suspension of solids. Further investigation would be necessary to evaluate its utility for radioactive waste treatment applications. This project did not uncover a new technology for radioactive waste treatment. While it may be possible that an efficient electrically driven technology for aerosol treatment could be developed, it appears that other technologies, such as steel and ceramic HEPA filters, can suitably solve this problem. If further studies are to be undertaken, additional fundamental experimentation and modeling is necessary to fully capture the physics; in addition, larger-scale tests are needed to demonstrate the treatment of flowing gas streams through the coupling of acoustic agglomeration with electrocoalescence.

  18. Synergy between Secondary Organic Aerosols and Long Range Transport...

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

    between Secondary Organic Aerosols and Long Range Transport of Polycyclic Aromatic Hydrocarbons. Synergy between Secondary Organic Aerosols and Long Range Transport of Polycyclic...

  19. acid aerosol exposure: Topics by E-print Network

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

    Nenes, Athanasios 8 Neutralization of soil aerosol and its impact on the distribution of acid rain over east Asia Geosciences Websites Summary: Neutralization of soil aerosol and...

  20. Spectro-Microscopic Measurements of Carbonaceous Aerosol Aging...

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

    of Carbonaceous Aerosol Aging in Central California. Abstract: Carbonaceous aerosols are responsible for large uncertainties in climate models, degraded visibility, and...

  1. Measurements of submicron aerosols in Houston, Texas during the...

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

    of submicron aerosols in Houston, Texas during the 2009 SHARP field campaign. Measurements of submicron aerosols in Houston, Texas during the 2009 SHARP field campaign. Abstract:...

  2. Building America Webinar: Sealing of Home Enclosures with Aerosol...

    Energy Savers [EERE]

    Sealing of Home Enclosures with Aerosol Particles Building America Webinar: Sealing of Home Enclosures with Aerosol Particles This webinar was presented by research team Building...

  3. The dependence of ice microphysics on aerosol concentration in...

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

    The dependence of ice microphysics on aerosol concentration in arctic mixed-phase stratus clouds during ISDAC and M-PACE. The dependence of ice microphysics on aerosol...

  4. Reduction in biomass burning aerosol light absorption upon humidificat...

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

    in biomass burning aerosol light absorption upon humidification: Roles of inorganically-induced hygroscopicity, Reduction in biomass burning aerosol light absorption upon...

  5. aerosols iii morphologic: Topics by E-print Network

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

    Sciences Websites Summary: of aerosols. Keywords: metal waste recycling; aerosols; fire hazard; explosion hazard. 1. OVERVIEW ProductsRisks generated by the treatment of...

  6. Molecular Chemistry of Organic Aerosols Through the Application...

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

    Chemistry of Organic Aerosols Through the Application of High Resolution Mass Spectrometry. Molecular Chemistry of Organic Aerosols Through the Application of High Resolution Mass...

  7. Comparative Analysis of Urban Atmospheric Aerosol by Particle...

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

    Analysis of Urban Atmospheric Aerosol by Particle-Induced X-ray Emission (PIXE), Proton Elastic Scattering Analysis Comparative Analysis of Urban Atmospheric Aerosol by...

  8. ambient aerosol concentrations: Topics by E-print Network

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

    soluble in water: 2. Isolation of acid, neutral, and basic fractions by modified size Weber, Rodney 4 Ambient aerosol sampling using the Aerodyne Aerosol Mass Spectrometer...

  9. ambient ultrafine aerosols: Topics by E-print Network

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

    soluble in water: 2. Isolation of acid, neutral, and basic fractions by modified size Weber, Rodney 4 Ambient aerosol sampling using the Aerodyne Aerosol Mass Spectrometer...

  10. aerosol flow reactor: Topics by E-print Network

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

    APPROACH TO SPACEBORN HYPERSPECTRAL OPTICAL FLOW ESTIMATION ON DUST AEROSOLS Fabian E, Canada ABSTRACT The significant role dust aerosols play in the earth's climate sys- tem and...

  11. aerosol formation durint: Topics by E-print Network

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

    XI, Universit de 86 8, 68456901, 2008 Aerosol optical Physics Websites Summary: of solar radiation by atmospheric aerosols is a key el- ement of the Earth's radiative energy...

  12. The Indirect and Semi-Direct Aerosol Campaign

    ScienceCinema (OSTI)

    Ghan, Steve

    2014-06-12T23:59:59.000Z

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

  13. aerosol ratio program: Topics by E-print Network

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

    contribute a major portion of atmospheric aerosol mass loading 5. The estimated global annual Liou, K. N. 2 Studying Clouds and Aerosols with Lidar Depolarization Ratio and...

  14. aerosol optical thickness: Topics by E-print Network

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

    of solar radiation by atmospheric aerosols is a key el- ement of the Earth's radiative energy balance and climate. The optical properties of aerosol particles are, however,...

  15. aerosol black carbon: Topics by E-print Network

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

    of solar radiation by atmospheric aerosols is a key el- ement of the Earth's radiative energy balance and climate. The optical properties of aerosol particles are, however,...

  16. The Indirect and Semi-Direct Aerosol Campaign

    SciTech Connect (OSTI)

    Ghan, Steve

    2014-03-24T23:59:59.000Z

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

  17. aerosol samples collected: Topics by E-print Network

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

    elements analysis of aerosol samples from some CiteSeer Summary: Aerosols deposits on filters from ten Romanian towns with different kinds and levels of industrial development...

  18. aerosol particles emitted: Topics by E-print Network

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

    aerosols scatter and absorb solar, estimates of the impact of aerosols on visibility, the solar radiation balance, and crop production is presented. 1. INTRODUCTION The attenuation...

  19. aerosol size classification: Topics by E-print Network

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

    2006 Aerosol size Physics Websites Summary: ACPD 6, 10493-10522, 2006 Aerosol size distribution source identification T. W. Chan and M Esc Printer-friendly Version...

  20. aerosolized pentamidine effect: Topics by E-print Network

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

    ON CCN CONCENTRATION AND AEROSOL FIRST INDIRECT RADIATIVE composition, aerosol size distribution is the more dominant parameter on CCN activation Feingold, GRL 2003;...

  1. aerosol monitoring: Topics by E-print Network

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

    ON CCN CONCENTRATION AND AEROSOL FIRST INDIRECT RADIATIVE composition, aerosol size distribution is the more dominant parameter on CCN activation Feingold, GRL 2003;...

  2. aerosols radioactifs artificiels: Topics by E-print Network

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

    ON CCN CONCENTRATION AND AEROSOL FIRST INDIRECT RADIATIVE composition, aerosol size distribution is the more dominant parameter on CCN activation Feingold, GRL 2003;...

  3. aerosolized polymerized type: Topics by E-print Network

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

    ON CCN CONCENTRATION AND AEROSOL FIRST INDIRECT RADIATIVE composition, aerosol size distribution is the more dominant parameter on CCN activation Feingold, GRL 2003;...

  4. aerosol concentration enrichment: Topics by E-print Network

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

    ON CCN CONCENTRATION AND AEROSOL FIRST INDIRECT RADIATIVE composition, aerosol size distribution is the more dominant parameter on CCN activation Feingold, GRL 2003;...

  5. aerosol direct radiative: Topics by E-print Network

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

    ON CCN CONCENTRATION AND AEROSOL FIRST INDIRECT RADIATIVE composition, aerosol size distribution is the more dominant parameter on CCN activation Feingold, GRL 2003;...

  6. aerosol biokinetics concentrations: Topics by E-print Network

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

    ON CCN CONCENTRATION AND AEROSOL FIRST INDIRECT RADIATIVE composition, aerosol size distribution is the more dominant parameter on CCN activation Feingold, GRL 2003;...

  7. aerosol particle analysis: Topics by E-print Network

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

    Summary: data analysis algorithm is presented. Our earlier algorithm assumed a monomodal aerosol size distribution, while the new algorithm allows us to partition the aerosol...

  8. aerosol radiative forcing: Topics by E-print Network

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

    ON CCN CONCENTRATION AND AEROSOL FIRST INDIRECT RADIATIVE composition, aerosol size distribution is the more dominant parameter on CCN activation Feingold, GRL 2003;...

  9. aerosol research study: Topics by E-print Network

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

    in atmospheric thermal structure, burning, bio-sources changes? 12;Aerosol microphysics: size distribution, mixing state, morphology, shape 9 Aerosol Science and Technology,...

  10. aerosol chemical composition: Topics by E-print Network

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

    ON CCN CONCENTRATION AND AEROSOL FIRST INDIRECT RADIATIVE composition, aerosol size distribution is the more dominant parameter on CCN activation Feingold, GRL 2003;...

  11. Limits of control for quantum systems: kinematical bounds on the optimization of observables and the question of dynamical realizability

    E-Print Network [OSTI]

    S. G. Schirmer; J. V. Leahy

    2000-10-07T23:59:59.000Z

    In this paper we investigate the limits of control for mixed-state quantum systems. The constraint of unitary evolution for non-dissipative quantum systems imposes kinematical bounds on the optimization of arbitrary observables. We summarize our previous results on kinematical bounds and show that these bounds are dynamically realizable for completely controllable systems. Moreover, we establish improved bounds for certain partially controllable systems. Finally, the question of dynamical realizability of the bounds for arbitary partially controllable systems is shown to depend on the accessible sets of the associated control system on the unitary group U(N) and the results of a few control computations are discussed briefly.

  12. Spent fuel sabotage aerosol test program :FY 2005-06 testing and aerosol data summary.

    SciTech Connect (OSTI)

    Gregson, Michael Warren; Brockmann, John E.; Nolte, O. (Fraunhofer institut fur toxikologie und experimentelle Medizin, Germany); Loiseau, O. (Institut de radioprotection et de Surete Nucleaire, France); Koch, W. (Fraunhofer institut fur toxikologie und experimentelle Medizin, Germany); Molecke, Martin Alan; Autrusson, Bruno (Institut de radioprotection et de Surete Nucleaire, France); Pretzsch, Gunter Guido (Gesellschaft fur anlagen- und Reaktorsicherheit, Germany); Billone, M. C. (Argonne National Laboratory, USA); Lucero, Daniel A.; Burtseva, T. (Argonne National Laboratory, USA); Brucher, W (Gesellschaft fur anlagen- und Reaktorsicherheit, Germany); Steyskal, Michele D.

    2006-10-01T23:59:59.000Z

    This multinational, multi-phase spent fuel sabotage test program is quantifying the aerosol particles produced when the products of a high energy density device (HEDD) interact with and explosively particulate test rodlets that contain pellets of either surrogate materials or actual spent fuel. This program has been underway for several years. This program provides source-term data that are relevant to some sabotage scenarios in relation to spent fuel transport and storage casks, and associated risk assessments. This document focuses on an updated description of the test program and test components for all work and plans made, or revised, primarily during FY 2005 and about the first two-thirds of FY 2006. It also serves as a program status report as of the end of May 2006. We provide details on the significant findings on aerosol results and observations from the recently completed Phase 2 surrogate material tests using cerium oxide ceramic pellets in test rodlets plus non-radioactive fission product dopants. Results include: respirable fractions produced; amounts, nuclide content, and produced particle size distributions and morphology; status on determination of the spent fuel ratio, SFR (the ratio of respirable particles from real spent fuel/respirables from surrogate spent fuel, measured under closely matched test conditions, in a contained test chamber); and, measurements of enhanced volatile fission product species sorption onto respirable particles. We discuss progress and results for the first three, recently performed Phase 3 tests using depleted uranium oxide, DUO{sub 2}, test rodlets. We will also review the status of preparations and the final Phase 4 tests in this program, using short rodlets containing actual spent fuel from U.S. PWR reactors, with both high- and lower-burnup fuel. These data plus testing results and design are tailored to support and guide, follow-on computer modeling of aerosol dispersal hazards and radiological consequence assessments. This spent fuel sabotage--aerosol test program, performed primarily at Sandia National Laboratories, with support provided by both the U.S. Department of Energy and the Nuclear Regulatory Commission, had significant inputs from, and is strongly supported and coordinated by both the U.S. and international program participants in Germany, France, and the U.K., as part of the international Working Group for Sabotage Concerns of Transport and Storage Casks, WGSTSC.

  13. Laboratory and field studies of combustion aerosol from the viewpoint of the nuclear winter scenario. Annual summary

    SciTech Connect (OSTI)

    Hallett, J.

    1985-12-01T23:59:59.000Z

    The nuclear winter scenario postulates that aerosol produced by widespread fires following a nuclear exchange is lofted to mid and upper tropospheric levels where it absorbs solar radiation (0.3 to 4 ..mu..m), but permits loss of thermal radiation (4 to 20 ..mu..m). This paper discusses possible removal and modification of the aerosol by cloud and precipitation processes which might take place during this period. Aerosol was produced from a selection of likely materials, its physical characteristics - (particle size, particle shape, coagulation rate) examined and its ability to form cloud droplets or ice crystals tested under conditions typical of a cloud system, both natural and perturbed by large scale fires. A numerical model of condensation growth has been used to illustrate the role of competition in growth of cloud droplets. During the first year we have looked at low aerosol concentration; during the coming year we will look at high aerosol concentrations and its influence on optical properties.

  14. Ice Nucleation Kinetics of Aerosols Containing Aqueous and Solid Ammonium Sulfate Hui-Ming Hung, Adam Malinowski, and Scot T. Martin*

    E-Print Network [OSTI]

    Ice Nucleation Kinetics of Aerosols Containing Aqueous and Solid Ammonium Sulfate Particles Hui; In Final Form: September 20, 2001 Ice freezing events in aerosols composed of (NH4)2SO4/H2O particles. Although they have similar apparent mole fraction compositions, the observed ice freezing characteristics

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

    SciTech Connect (OSTI)

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

    2012-07-25T23:59:59.000Z

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

  16. Heterogeneous Chemistry: Understanding Aerosol/Oxidant Interactions

    SciTech Connect (OSTI)

    Joyce E. Penner

    2005-03-14T23:59:59.000Z

    Global radiative forcing of nitrate and ammonium aerosols has mostly been estimated from aerosol concentrations calculated at thermodynamic equilibrium or using approximate treatments for their uptake by aerosols. In this study, a more accurate hybrid dynamical approach (DYN) was used to simulate the uptake of nitrate and ammonium by aerosols and the interaction with tropospheric reactive nitrogen chemistry in a three-dimensional global aerosol and chemistry model, IMPACT, which also treats sulfate, sea salt and mineral dust aerosol. 43% of the global annual average nitrate aerosol burden, 0.16 TgN, and 92% of the global annual average ammonium aerosol burden, 0.29 TgN, exist in the fine mode (D<1.25 {micro}m) that scatters most efficiently. Results from an equilibrium calculation differ significantly from those of DYN since the fraction of fine-mode nitrate to total nitrate (gas plus aerosol) is 9.8%, compared to 13% in DYN. Our results suggest that the estimates of aerosol forcing from equilibrium concentrations will be underestimated. We also show that two common approaches used to treat nitrate and ammonium in aerosol in global models, including the first-order gas-to-particle approximation based on uptake coefficients (UPTAKE) and a hybrid method that combines the former with an equilibrium model (HYB), significantly overpredict the nitrate uptake by aerosols especially that by coarse particles, resulting in total nitrate aerosol burdens higher than that in DYN by +106% and +47%, respectively. Thus, nitrate aerosol in the coarse mode calculated by HYB is 0.18 Tg N, a factor of 2 more than that in DYN (0.086 Tg N). Excessive formation of the coarse-mode nitrate in HYB leads to near surface nitrate concentrations in the fine mode lower than that in DYN by up to 50% over continents. In addition, near-surface HNO{sub 3} and NO{sub x} concentrations are underpredicted by HYB by up to 90% and 5%, respectively. UPTAKE overpredicts the NO{sub x} burden by 56% and near-surface NO{sub x} concentrations by a factor of 2-5. These results suggest the importance of using the more accurate hybrid dynamical method in the estimates of both aerosol forcing and tropospheric ozone chemistry.

  17. Characterization of aerosols produced by surgical procedures

    SciTech Connect (OSTI)

    Yeh, H.C.; Muggenburg, B.A.; Lundgren, D.L.; Guilmette, R.A.; Snipes, M.B.; Jones, R.K. [Inhalation Toxicology Research Institute, Albuquerque, NM (United States); Turner, R.S. [Lovelace Health Systems, Albuquerque, NM (United States)

    1994-07-01T23:59:59.000Z

    In many surgeries, especially orthopedic procedures, power tools such as saws and drills are used. These tools may produce aerosolized blood and other biological material from bone and soft tissues. Surgical lasers and electrocautery tools can also produce aerosols when tissues are vaporized and condensed. Studies have been reported in the literature concerning production of aerosols during surgery, and some of these aerosols may contain infectious material. Garden et al. (1988) reported the presence of papilloma virus DNA in the fumes produced from laser surgery, but the infectivity of the aerosol was not assessed. Moon and Nininger (1989) measured the size distribution and production rate of emissions from laser surgery and found that particles were generally less than 0.5 {mu}m diameter. More recently there has been concern expressed over the production of aerosolized blood during surgical procedures that require power tools. In an in vitro study, the production of an aerosol containing the human immunodeficiency virus (HIV) was reported when power tools were used to cut tissues with blood infected with HIV. Another study measured the size distribution of blood aerosols produced by surgical power tools and found blood-containing particles in a number of size ranges. Health care workers are anxious and concerned about whether surgically produced aerosols are inspirable and can contain viable pathogens such as HIV. Other pathogens such as hepatitis B virus (HBV) are also of concern. The Occupational Safety and Health funded a project at the National Institute for Inhalation Toxicology Research Institute to assess the extent of aerosolization of blood and other tissues during surgical procedures. This document reports details of the experimental and sampling approach, methods, analyses, and results on potential production of blood-associated aerosols from surgical procedures in the laboratory and in the hospital surgical suite.

  18. Measurements of Aerosol Charge and Size Distribution for Graphite, Gold, Palladium, and Silver Nanoparticles

    SciTech Connect (OSTI)

    Simones, Matthew P.; Gutti, Veera R.; Meyer, Ryan M.; Loyalka, Sudarshan K.

    2011-11-01T23:59:59.000Z

    The role of charge on aerosol evolution and hence the nuclear source term has been an issue of interest, and there is a need for both experimental techniques and modeling for quantifying this role. Our focus here is on further exploration of a tandem differential mobility analyzer (TDMA) technique to simultaneously measure both the size and charge (positive, negative and neutral) dependent aerosol distributions. We have generated graphite, gold, silver, and palladium nanoparticles (aerosol) using a spark generator. We measure the electrical mobility-size distributions for these aerosols using a TDMA, and from these data we deduce the full charge-size distributions. We observe asymmetry in the particle size distributions for negative and positive charges. This asymmetry could have a bearing on the dynamics of charged aerosols, indicating that the assumption of symmetry for size distributions of negatively and positively charged particles in source term simulations may not be always appropriate. Also, the experimental technique should find applications in measurements of aerosol rate processes that are affected by both particle charge and size (e.g. coagulation, deposition, resuspension), and hence in modeling and simulation of the nuclear source term.

  19. 2372 IEEE TRANSACTIONS ON AUTOMATIC CONTROL, VOL. 58, NO. 9, SEPTEMBER 2013 Observability of a Linear System Under

    E-Print Network [OSTI]

    Yüksel, Serdar

    notion of controllability, these form the essence of modern linear control theory. In this technical note states intact. Furthermore, with the increasing emphasis on networked control systems, it has been realized that the controllability and observability concepts for linear systems with controllers having

  20. Observers for Interconnected Nonlinear and Linear Systems Havard Fjr Grip a, Ali Saberi a, and Tor A. Johansen b

    E-Print Network [OSTI]

    Johansen, Tor Arne

    Observers for Interconnected Nonlinear and Linear Systems H°avard Fjær Grip a, Ali Saberi a (Esfandiari and Khalil, 1987; Saberi and Sannuti, 1990), and non-left-invertible systems (e.g., Gauthier, Hammouri, and Othman, 1992; Bornard and Hammouri, 2002; Grip and Saberi, 2010); the exploitation

  1. Investigation of Aerosol Indirect Effects using a Cumulus Microphysics Parameterization in a Regional Climate Model

    SciTech Connect (OSTI)

    Lim, Kyo-Sun; Fan, Jiwen; Leung, Lai-Yung R.; Ma, Po-Lun; Singh, Balwinder; Zhao, Chun; Zhang, Yang; Zhang, Guang; Song, Xiaoliang

    2014-01-29T23:59:59.000Z

    A new Zhang and McFarlane (ZM) cumulus scheme includes a two-moment cloud microphysics parameterization for convective clouds. This allows aerosol effects to be investigated more comprehensively by linking aerosols with microphysical processes in both stratiform clouds that are explicitly resolved and convective clouds that are parameterized in climate models. This new scheme is implemented in the Weather Research and Forecasting (WRF) model, which is coupled with the physics and aerosol packages from the Community Atmospheric Model version 5 (CAM5). A test case of July 2008 during the East Asian summer monsoon is selected to evaluate the performance of the new ZM scheme and to investigate aerosol effects on monsoon precipitation. The precipitation and radiative fluxes simulated by the new ZM scheme show a better agreement with observations compared to simulations with the original ZM scheme that does not include convective cloud microphysics and aerosol convective cloud interactions. Detailed analysis suggests that an increase in detrained cloud water and ice mass by the new ZM scheme is responsible for this improvement. To investigate precipitation response to increased anthropogenic aerosols, a sensitivity experiment is performed that mimics a clean environment by reducing the primary aerosols and anthropogenic emissions to 30% of that used in the control simulation of a polluted environment. The simulated surface precipitation is reduced by 9.8% from clean to polluted environment and the reduction is less significant when microphysics processes are excluded from the cumulus clouds. Ensemble experiments with ten members under each condition (i.e., clean and polluted) indicate similar response of the monsoon precipitation to increasing aerosols.

  2. SMA Observations of Class 0 Protostars: A High-Angular Resolution Survey of Protostellar Binary Systems

    E-Print Network [OSTI]

    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

    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...

  3. Effect of the N. Delta. interaction on observables of the. pi. NN and. gamma. NN systems

    SciTech Connect (OSTI)

    Pena, M.T. (Centro de Fisica Nuclear da Universidade de Lisboa (INIC), 1699 Lisboa Codex (Portugal)); Garcilazo, H. (Theoretical Physics, University of Hannover, D-3000 Hannover (Germany)); Oelfke, U. (TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia (Canada)); Sauer, P.U. (Theoretical Physics, University of Hannover, D-3000 Hannover (Germany) Nuclear Theory Group, Department of Physics, FM-15, University of Washington , Seattle, Washington 98195 (United States))

    1992-04-01T23:59:59.000Z

    Effects on the hadronic and electromagnetic properties of the two-nucleon system above pion threshold, arising from the interaction of the {Delta} isobar with nucleons, are investigated. The instantaneous nucleon-{Delta} potential is based on the meson exchange. Two-body reactions connecting channels with at most one pion and one photon are studied. Processes leading to a three-body pion-two-nucleon final state are considered in the restricted kinematic domain in which the pion forms the {ital P}{sub 33} resonance with one of the nucleons. The nucleon-{Delta} potential is seen to increase the relative importance of the inelastic strength of two-nucleon spin-triplet states with respect to spin-singlet states, correcting a deficiency common in most existing models. Theoretical predictions are compared with recent experimental data for the various reactions. In particular, the differential cross section and the proton beam asymmetry for {ital pp}{r arrow}{ital n}{Delta}{sup ++} ({ital p}{pi}{sup +}) are calculated, the latter observable being especially sensitive to the nucleon-{Delta} interaction.

  4. Biobriefcase aerosol collector

    DOE Patents [OSTI]

    Bell, Perry M. (Tracy, CA); Christian, Allen T. (Madison, WI); Bailey, Christopher G. (Pleasanton, CA); Willis, Ladona (Manteca, CA); Masquelier, Donald A. (Tracy, CA); Nasarabadi, Shanavaz L. (Livermore, CA)

    2009-09-22T23:59:59.000Z

    A system for sampling air and collecting particles entrained in the air that potentially include bioagents. The system comprises providing a receiving surface, directing a liquid to the receiving surface and producing a liquid surface. Collecting samples of the air and directing the samples of air so that the samples of air with particles entrained in the air impact the liquid surface. The particles potentially including bioagents become captured in the liquid. The air with particles entrained in the air impacts the liquid surface with sufficient velocity to entrain the particles into the liquid but cause minor turbulence. The liquid surface has a surface tension and the collector samples the air and directs the air to the liquid surface so that the air with particles entrained in the air impacts the liquid surface with sufficient velocity to entrain the particles into the liquid, but cause minor turbulence on the surface resulting in insignificant evaporation of the liquid.

  5. Global distribution and climate forcing of marine organic aerosol: 1. Model improvements and evaluation

    SciTech Connect (OSTI)

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

    2011-11-23T23:59:59.000Z

    Marine organic aerosol emissions have been implemented and evaluated within the National Center of Atmospheric Research (NCAR)'s Community Atmosphere Model (CAM5) with the Pacific Northwest National Laboratory's 7-mode Modal Aerosol Module (MAM-7). Emissions of marine primary organic aerosols (POA), phytoplanktonproduced isoprene- and monoterpenes-derived secondary organic aerosols (SOA) and methane sulfonate (MS{sup -}) are shown to affect surface concentrations of organic aerosols in remote marine regions. Global emissions of submicron marine POA is estimated to be 7.9 and 9.4 Tg yr{sup -1}, for the Gantt et al. (2011) and Vignati et al. (2010) emission parameterizations, respectively. Marine sources of SOA and particulate MS{sup -} (containing both sulfur and carbon atoms) contribute an additional 0.2 and 5.1 Tg yr{sup -1}, respectively. Widespread areas over productive waters of the Northern Atlantic, Northern Pacific, and the Southern Ocean show marine-source submicron organic aerosol surface concentrations of 100 ngm{sup -3}, with values up to 400 ngm{sup -3} over biologically productive areas. Comparison of long-term surface observations of water insoluble organic matter (WIOM) with POA concentrations from the two emission parameterizations shows that despite revealed discrepancies (often more than a factor of 2), both Gantt et al. (2011) and Vignati et al. (2010) formulations are able to capture the magnitude of marine organic aerosol concentrations, with the Gantt et al. (2011) parameterization attaining better seasonality. Model simulations show that the mixing state of the marine POA can impact the surface number concentration of cloud condensation nuclei (CCN). The largest increases (up to 20 %) in CCN (at a supersaturation (S) of 0.2 %) number concentration are obtained over biologically productive ocean waters when marine organic aerosol is assumed to be externally mixed with sea-salt. Assuming marine organics are internally-mixed with sea-salt provides diverse results with increases and decreases in the concentration of CCN over different parts of the ocean. The sign of the CCN change due to the addition of marine organics to seasalt aerosol is determined by the relative significance of the increase in mean modal diameter due to addition of mass, and the decrease in particle hygroscopicity due to compositional changes in marine aerosol. Based on emerging evidence for increased CCN concentration over biologically active surface ocean areas/periods, our study suggests that treatment of sea spray in global climate models (GCMs) as an internal mixture of marine organic aerosols and sea-salt will likely lead to an underestimation in CCN number concentration.

  6. Aerosol Condensational Growth in Cloud Formation

    E-Print Network [OSTI]

    Geng, Jun

    2010-10-12T23:59:59.000Z

    A code for the quasi-stationary solution of the coupled heat and mass transport equations for aerosols in a finite volume was developed. Both mass and heat are conserved effectively in the volume, which results in a competitive aerosol condensation...

  7. 6, 32653319, 2006 Study aerosol with

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    ACPD 6, 3265­3319, 2006 Study aerosol with two emission inventories and time factors A. de Meij et in Europe to two different emission inventories and temporal distribution of emissions A. de Meij 1 , M Study aerosol with two emission inventories and time factors A. de Meij et al. Title Page Abstract

  8. 5, 75777611, 2005 A look at aerosol

    E-Print Network [OSTI]

    Boyer, Edmond

    ACPD 5, 7577­7611, 2005 A look at aerosol formation using data mining techniques S. Hyv and Physics Discussions A look at aerosol formation using data mining techniques S. Hyv¨onen1 , H. Junninen2 Korkeakoski, Finland 4 Department of Forest Ecology, Faculty of Agriculture and Forestry, P.O. Box 27, FIN

  9. 2, 12871315, 2002 Aerosol sources and

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    in climate variability and climate change studies (IPCC, 2001). Radiative forcing of natural and their contribution to the chemical composition of aerosols in the Eastern Mediterranean Sea during summertime J aerosol sources in the Eastern Mediterranean5 Basin could be investigated at this location since the site

  10. Systems and Algorithms for Automated Collaborative Observation using Networked Robotic Cameras 

    E-Print Network [OSTI]

    Xu, Yiliang

    2011-10-21T23:59:59.000Z

    The development of telerobotic systems has evolved from Single Operator Single Robot (SOSR) systems to Multiple Operator Multiple Robot (MOMR) systems. The relationship between human operators and robots follows the ...

  11. Systems and Algorithms for Automated Collaborative Observation using Networked Robotic Cameras

    E-Print Network [OSTI]

    Xu, Yiliang

    2011-10-21T23:59:59.000Z

    The development of telerobotic systems has evolved from Single Operator Single Robot (SOSR) systems to Multiple Operator Multiple Robot (MOMR) systems. The relationship between human operators and robots follows the master-slave control architecture...

  12. THE INFLUENCE OF BENZENE AS A TRACE REACTANT IN TITAN AEROSOL ANALOGS

    SciTech Connect (OSTI)

    Trainer, Melissa G. [Planetary Environments Laboratory, Code 699, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Sebree, Joshua A. [NASA Postdoctoral Program Fellow, Code 699, Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Heidi Yoon, Y.; Tolbert, Margaret A., E-mail: melissa.trainer@nasa.gov [Cooperative Institute for Research in Environmental Sciences, University of Colorado at Boulder, Box 216 UCB, Boulder, CO 80309 (United States)

    2013-03-20T23:59:59.000Z

    Benzene has been detected in Titan's atmosphere by Cassini instruments, with concentrations ranging from sub-ppb in the stratosphere to ppm in the ionosphere. Sustained levels of benzene in the haze formation region could signify that it is an important reactant in the formation of Titan's organic aerosol. To date, there have not been laboratory investigations to assess the influence of benzene on aerosol properties. We report a laboratory study on the chemical composition of organic aerosol formed from C{sub 6}H{sub 6}/CH{sub 4}/N{sub 2} via far ultraviolet irradiation (120-200 nm). The compositional results are compared to those from aerosol generated by a more ''traditional Titan'' mixture of CH{sub 4}/N{sub 2}. Our results show that even a trace amount of C{sub 6}H{sub 6} (10 ppm) has significant impact on the chemical composition and production rates of organic aerosol. There are several pathways by which photolyzed benzene may react to form larger molecules, both with and without the presence of CH{sub 4}, but many of these reaction mechanisms are only beginning to be explored for the conditions at Titan. Continued work investigating the influence of benzene in aerosol growth will advance understanding of this previously unstudied reaction system.

  13. ARM - AOS Aerosol Properties Plots

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOnItemResearchSOLICITATIONIMODI FICATION OF CONTRACTOperations AMF2ViewersAOS Aerosol

  14. The importance of aerosol mixing state and size-resolved composition on CCN concentration and the variation of the importance with atmospheric aging of aerosols

    SciTech Connect (OSTI)

    Wang, J.; Cubison, M. J.; Aiken, A. C.; Jimenez, J. L.; Collins, D. R.

    2010-05-01T23:59:59.000Z

    Aerosol microphysics, chemical composition, and CCN concentrations were measured at the T0 urban supersite in Mexico City during Megacity Initiative: Local and Global Research Observations (MILAGRO) in March 2006. The aerosol size distribution and composition often showed strong diurnal variation associated with traffic emissions and aging of aerosols through coagulation and local photochemical production of secondary aerosol species. CCN concentrations (N{sub CCN}) are derived using Kohler theory from the measured aerosol size distribution and various simplified aerosol mixing state and chemical composition, and are compared to concurrent measurements at five supersaturations ranging from 0.11% to 0.35%. The influence of assumed mixing state on calculated N{sub CCN} is examined using both aerosols observed during MILAGRO and representative aerosol types. The results indicate that while ambient aerosols often consist of particles with a wide range of compositions at a given size, N{sub CCN} may be derived within {approx}20% assuming an internal mixture (i.e., particles at a given size are mixtures of all participating species, and have the identical composition) if great majority of particles has an overall {kappa} (hygroscopicity parameter) value greater than 0.1. For a non-hygroscopic particle with a diameter of 100 nm, a 3 nm coating of sulfate or nitrate is sufficient to increase its {kappa} from 0 to 0.1. The measurements during MILAGRO suggest that the mixing of non-hygroscopic primary organic aerosol (POA) and black carbon (BC) particles with photochemically produced hygroscopic species and thereby the increase of their {kappa} to 0.1 take place in a few hours during daytime. This rapid process suggests that during daytime, a few tens of kilometers away for POA and BC sources, N{sub CCN} may be derived with sufficient accuracy by assuming an internal mixture, and using bulk chemical composition. The rapid mixing also indicates that, at least for very active photochemical environments such as Mexico City, a substantially shorter timescale during daytime for the conversion of hydrophobic POA and BC to hydrophilic particles than the 1-2 days used in some global models. The conversion time scale is substantially longer during night. Most POA and BC particles emitted during evening hours likely remain non-hygroscopic until efficiently internally mixed with secondary species in the next morning. The results also suggest that the assumed mixing state strongly impacts calculated N{sub CCN} only when POA and BC represent a large fraction of the total aerosol volume. One of the implications is that while physically unrealistic, external mixtures, which are used in many global models, may also sufficiently predict N{sub CCN} for aged aerosol, as the contribution of non-hygroscopic POA and BC to overall aerosol volume is often substantially reduced due to the condensation of secondary species.

  15. A sea-state based source function for size and composition resolved marine aerosol

    SciTech Connect (OSTI)

    Long, Michael S [ORNL; Keene, William C [ORNL; Erickson III, David J [ORNL

    2011-01-01T23:59:59.000Z

    A parameterization for the size- and composition-resolved production fluxes of nascent marine aerosol was developed from prior experimental observations and extrapolated to ambient conditions based on estimates of air entrainment by the breaking of wind-driven ocean waves. Production of particulate organic carbon (OC{sub aer}) was parameterized based on Langmuir equilibrium-type association of organic matter to bubble plumes in seawater and resulting aerosol as constrained by measurements of aerosol produced from productive and oligotrophic seawater. This novel approach is the first to parameterize size- and composition-resolved aerosol production based on explicit evaluation of wind-driven air entrainment/detrainment fluxes and chlorophyll-a as a proxy for surfactants in surface seawater. Production fluxes were simulated globally with an eight aerosol-size-bin version of the NCAR Community Atmosphere Model (CAM v3.5.07). Simulated production fluxes fell within the range of published estimates based on observationally constrained parameterizations. Because the parameterization does not consider contributions from spume drops, the simulated global mass flux (1.5 x 10{sup 3} Tg y{sup -1}) is near the lower end of published estimates. The simulated production of aerosol number (1.4 x 10{sup 6} m{sup -2} s{sup -1}) and OC{sub aer} (29 Tg C y{sup -1}) fall near the upper end of published estimates and suggest that primary marine aerosols may have greater influences on the physicochemical evolution of the troposphere, radiative transfer and climate, and associated feedbacks on the surface ocean than suggested by previous model studies.

  16. Biobriefcase electrostatic aerosol collector

    DOE Patents [OSTI]

    Bell, Perry M. (Tracy, CA); Christian, Allen T. (Madison, WI); Bailey, Christopher G. (Pleasanton, CA); Willis, Ladona (Manteca, CA); Masquelier, Donald A. (Tracy, CA); Nasarabadi, Shanavaz L. (Livermore, CA)

    2009-03-17T23:59:59.000Z

    A system for sampling air and collecting particles entrained in the air comprising a receiving surface, a liquid input that directs liquid to the receiving surface and produces a liquid surface, an air input that directs the air so that the air with particles entrained in the air impact the liquid surface, and an electrostatic contact connected to the liquid that imparts an electric charge to the liquid. The particles potentially including bioagents become captured in the liquid by the air with particles entrained in the air impacting the liquid surface. Collection efficiency is improved by the electrostatic contact electrically charging the liquid. The effects of impaction and adhesion due to electrically charging the liquid allows a unique combination in a particle capture medium that has a low fluid consumption rate while maintaining high efficiency.

  17. Aerosol Releases from the ICPP July 2005 FINAL REPORT

    E-Print Network [OSTI]

    Aerosol Releases from the ICPP July 2005 FINAL REPORT AEROSOL RELEASES FROM THE IDAHO CHEMICAL, Inc. July 2005 #12;Aerosol Releases from the ICPP July 2005 TABLE OF CONTENTS 1.0 Introduction ......................................... 5-1 5.1 Beta-minus Iodine Aerosol Formation Mechanism

  18. Exploring matrix effects on photochemistry of organic aerosols

    E-Print Network [OSTI]

    Nizkorodov, Sergey

    Exploring matrix effects on photochemistry of organic aerosols Hanna Lignella,b,1 , Mallory L of photochemical processes in organic aerosols will depend on both relative humidity and temperature and thus and impacts. aerosol aging | particle viscosity | organic photochemistry Aqueous droplets and aerosol

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

    SciTech Connect (OSTI)

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

    2015-01-01T23:59:59.000Z

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

  20. Long-range forces and the collisions of free-molecular and transition regime aerosols

    SciTech Connect (OSTI)

    Marlow, W.H.

    1988-12-31T23:59:59.000Z

    An aerosol here is understood to be a two-component system comprised of gaseous and condensed phases with the characteristic that the condensed phase is not an equilibrium subsystem. In contrast to the usual definitions based upon geometrical or mechanical variables, this quasi-thermodynamic formulation is framed to emphasize the dynamical behavior of aerosols by allowing for coagulation and other aerosol evolutionary processes as natural consequences of the interactions and state variables appropriate to the system. As will become clear later, it also provides a point of departure for distinguishing aerosol particles from unstable gas-phase cluster systems. The question of accommodation in particle collisions must be addressed as a prelude to the discussion of the role of long-range forces. Microscopic reversibility is frequently assumed for molecular collisions with either molecules or solid surfaces. In the case of aerosol collisions, the implication of this assumption is that collisions are elastic, which is contrary to the evidence from coagulation experiments and the conventional operational assumption of sticking upon collision. Gay and Berne have performed computer simulations of the collision of two clusters consisting of a total of 135 molecules interacting via Lennard-Jones potentials. That work showed that complete accommodation, accompanied by overall heating of the unified cluster, occurred. Since heating represents an irreversible degradation of the kinetic energy of the collision, the hamiltonian of the two-cluster system should be considered as dissipative and therefore microscopic reversibility does not apply.

  1. Photolytically generated aerosols in the mesosphere and thermosphere of Titan

    E-Print Network [OSTI]

    Mao-Chang Liang; Yuk L. Yung; Donald E. Shemansky

    2007-05-03T23:59:59.000Z

    Analysis of the Cassini Ultraviolet Imaging Spectrometer (UVIS) stellar and solar occultations at Titan to date include 12 species: N$_{2}$ (nitrogen), CH$_{4}$ (methane), C$_{2}$H$_{2}$ (acetylene), C$_{2}$H$_{4}$ (ethylene), C$_{2}$H$_{6}$ (ethane), C$_{4}$H$_{2}$ (diacetylene), C$_{6}$H$_{6}$ (benzene), C$_{6}$N$_{2}$ (dicyanodiacetylene), C$_{2}$N$_{2}$ (cyanogen), HCN (hydrogen cyanide), HC$_{3}$N (cyanoacetylene), and aerosols distinguished by a structureless continuum extinction (absorption plus scattering) of photons in the EUV. The introduction of aerosol particles, retaining the same refractive index properties as tholin with radius $\\sim$125 \\AA and using Mie theory, provides a satisfactory fit to the spectra. The derived vertical profile of aerosol density shows distinct structure, implying a reactive generation process reaching altitudes more than 1000 km above the surface. A photochemical model presented here provides a reference basis for examining the chemical and physical processes leading to the distinctive atmospheric opacity at Titan. We find that dicyanodiacetylene is condensable at $\\sim$650 km, where the atmospheric temperature minimum is located. This species is the simplest molecule identified to be condensable. Observations are needed to confirm the existence and production rates of dicyanodiacetylene.

  2. Global impact of smoke aerosols from landscape fires on climate and the Hadley circulation

    E-Print Network [OSTI]

    Tosca, M. G; Randerson, J. T; Zender, C. S

    2013-01-01T23:59:59.000Z

    of biomass burn- ing aerosol on the monsoon circulationA. , and Rudich, Y. : Aerosol invigoration and restructuring2011. Albrecht, B. A. : Aerosols, cloud microphysics, and

  3. Characterization of the Molecular Composition of Secondary Organic Aerosols using High Resolution Mass Spectrometry

    E-Print Network [OSTI]

    Sellon, Rachel Elizabeth

    2012-01-01T23:59:59.000Z

    in secondary organic aerosol formation from isoprene, Proc.biogenic secondary organic aerosol, J. Phys. Chem. A, 112(in secondary organic aerosol, Environ. Sci. Technol. , 41(

  4. Chapter 3: Evaluating the impacts of carbonaceous aerosols on clouds and climate

    E-Print Network [OSTI]

    Menon, Surabi

    2008-01-01T23:59:59.000Z

    Cloud susceptibility and the first aerosol indirect forcing:Sensitivity to BC and aerosol concentrations. J. Geophys.of cloud droplet and aerosols number concentrations:

  5. Correlations between Optical, Chemical and Physical Properties of Biomass Burn Aerosols

    E-Print Network [OSTI]

    2008-01-01T23:59:59.000Z

    instruments and photoelectric aerosol sensors in source-sampling of black carbon aerosol and particle-bound PAHsAirborne minerals and related aerosol particles: Effects on

  6. Real time in situ detection of organic nitrates in atmospheric aerosols

    E-Print Network [OSTI]

    Rollins, Andrew W.

    2011-01-01T23:59:59.000Z

    Biogenic Secondary Organic Aerosol. J. Phys. Chem. A 2008,H. Secondary organic aerosol (SOA) formation from reactionsec- ondary organic aerosol yields. Atmospheric Chemistry

  7. Composition, sources, and formation of secondary organic aerosols from urban emissions

    E-Print Network [OSTI]

    Liu, Shang; Liu, Shang

    2012-01-01T23:59:59.000Z

    organonitrate functional groups in aerosol particles200 5.1v aerosol Chapter 3 Meteorological conditions during theSecondary organic aerosol formation from fossil fuel sources

  8. Particles, Aerosols, and Their Transport in Built Environment Particles, aerosols, or collectively called particulate matters (PM) are ubiquitous indoor

    E-Print Network [OSTI]

    Chen, Qingyan "Yan"

    1 Editorial Particles, Aerosols, and Their Transport in Built Environment Particles, aerosols or aerosols and their transport in built environment. The first five papers in this special issue addressed influences ozone removal and the secondary organic aerosols generation. The study from Zuraimi et al

  9. Sources and Formation of OrganicSources and Formation of Organic Aerosols in our AtmosphereAerosols in our Atmosphere

    E-Print Network [OSTI]

    Einat, Aharonov

    Sources and Formation of OrganicSources and Formation of Organic Aerosols in our AtmosphereAerosols Department of Chemical Engineering University of Patras, Greece #12;Sources of Organic AerosolSources of Organic Aerosol Primary Secondary Anthropogenic ·Gasoline ·Diesel ·Biomass burning ·Meat Cooking Biogenic

  10. Studying trends in biomass burning aerosol using the Absorbing Aerosol Index derived from GOME, SCIAMACHY, and GOME-2

    E-Print Network [OSTI]

    Tilstra, Gijsbert

    Studying trends in biomass burning aerosol using the Absorbing Aerosol Index derived from GOME the resulting time series, we use tropospheric NO2 data as a reference in the regions dominated by biomass sensitive to desert dust aerosols (DDA) and biomass burning aerosols (BBA). See Figure 1. The AAI

  11. Climatological simulations of ozone and atmospheric aerosols in the Greater Cairo region

    SciTech Connect (OSTI)

    Steiner, A. L.; Tawfik, A. B.; Shalaby, A.; Zakey, A. S.; Abdel Wahab, M. M.; Salah, Z.; Solmon, F.; Sillman, S.; Zaveri, Rahul A.

    2014-04-16T23:59:59.000Z

    An integrated chemistry-climate model (RegCM4-CHEM) simulates present-day climate, ozone and tropospheric aerosols over Egypt with a focus on Greater Cairo (GC) region. The densley populated GC region is known for its severe air quality issues driven by high levels of anthropogenic pollution in conjuction with natural sources such as dust and agricultural burning events. We find that current global emission inventories underestimate key pollutants such as nitrogen oxides and anthropogenic aerosol species. In the GC region, average-ground-based NO2 observations of 40-60 ppb are substantially higher than modeled estimates (5-10 ppb), likely due to model grid resolution, improper boundary layer representation, and poor emissions inventories. Observed ozone concentrations range from 35 ppb (winter) to 80 ppb (summer). The model reproduces the seasonal cycle fairly well, but modeled summer ozone is understimated by approximately 15 ppb and exhibits little interannual variability. For aerosols, springtime dust events dominate the seasonal aerosol cycle. The chemistry-climate model captures the springtime peak aerosol optical depth (AOD) of 0.7-1 but is slightly greater than satellite-derived AOD. Observed AOD decreases in the summer and increases again in the fall due to agricultural burning events in the Nile Delta, yet the model underestimates this fall observed AOD peak, as standard emissions inventories underestimate this burning and the resulting aerosol emissions. Our comparison of modeled gas and particulate phase atmospheric chemistry in the GC region indicates that improved emissions inventories of mobile sources and other anthropogenic activities are needed to improve air quality simulations in this region.

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

    SciTech Connect (OSTI)

    Zaveri, RA; Shaw, WJ; Cziczo, DJ

    2010-05-27T23:59:59.000Z

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

  13. Have Aerosols Caused the Observed Atlantic Multidecadal Variability?

    E-Print Network [OSTI]

    Zhang, Rong

    Identifying the prime drivers of the twentieth-century multidecadal variability in the Atlantic Ocean is crucial for predicting how the Atlantic will evolve in the coming decades and the resulting broad impacts on weather ...

  14. Aerosol, Cloud, and Climate: From Observation to Model

    ScienceCinema (OSTI)

    Jian Wang

    2010-09-01T23:59:59.000Z

    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.

  15. Aerosol, Cloud, and Climate: From Observation to Model

    SciTech Connect (OSTI)

    Jian Wang

    2010-05-12T23:59:59.000Z

    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.

  16. Defeating Network Node Subversion on SCADA Systems Using Probabilistic Packet Observation

    E-Print Network [OSTI]

    Sheldon, Nathan D.

    on SCADA systems was first proposed in [2]. It is assumed an operator has a model of a control system are manipulated. If no such manipulation takes place and the control signal is still anomalous, we can assume Supervisory control and data acquisition (SCADA) systems form a vital part of the critical infrastructure

  17. Improving Bulk Microphysics Parameterizations in Simulations of Aerosol Effects

    SciTech Connect (OSTI)

    Wang, Yuan; Fan, Jiwen; Zhang, Renyi; Leung, Lai-Yung R.; Franklin, Charmaine N.

    2013-06-05T23:59:59.000Z

    To improve the microphysical parameterizations for simulations of the aerosol indirect effect (AIE) in regional and global climate models, a double-moment bulk microphysical scheme presently implemented in the Weather Research and Forecasting (WRF) model is modified and the results are compared against atmospheric observations and simulations produced by a spectral bin microphysical scheme (SBM). Rather than using prescribed aerosols as in the original bulk scheme (Bulk-OR), a prognostic doublemoment aerosol representation is introduced to predict both the aerosol number concentration and mass mixing ratio (Bulk-2M). The impacts of the parameterizations of diffusional growth and autoconversion and the selection of the embryonic raindrop radius on the performance of the bulk microphysical scheme are also evaluated. Sensitivity modeling experiments are performed for two distinct cloud regimes, maritime warm stratocumulus clouds (SC) over southeast Pacific Ocean from the VOCALS project and continental deep convective clouds (DCC) in the southeast of China from the Department of Energy/ARM Mobile Facility (DOE/AMF) - China field campaign. The results from Bulk-2M exhibit a much better agreement in the cloud number concentration and effective droplet radius in both the SC and DCC cases with those from SBM and field measurements than those from Bulk-OR. In the SC case particularly, Bulk-2M reproduces the observed drizzle precipitation, which is largely inhibited in Bulk-OR. Bulk-2M predicts enhanced precipitation and invigorated convection with increased aerosol loading in the DCC case, consistent with the SBM simulation, while Bulk-OR predicts the opposite behaviors. Sensitivity experiments using four different types of autoconversion schemes reveal that the autoconversion parameterization is crucial in determining the raindrop number, mass concentration, and drizzle formation for warm 2 stratocumulus clouds. An embryonic raindrop size of 40 ?m is determined as a more realistic setting in the autoconversion parameterization. The saturation adjustment employed in calculating condensation/evaporation in the bulk scheme is identified as the main factor responsible for the large discrepancies in predicting cloud water in the SC case, suggesting that an explicit calculation of diffusion growth with predicted supersaturation is necessary for further improvements of the bulk microphysics scheme. Lastly, a larger rain evaporation rate below cloud is found in the bulk scheme in comparison to the SBM simulation, which could contribute to a lower surface precipitation in the bulk scheme.

  18. Ultrafine calcium aerosol: Generation and use as a sorbent for sulfur in coal combustion. Volume 1, Experimental work: Final report, August 1, 1988--October 31, 1991

    SciTech Connect (OSTI)

    Alam, M.K.; Nahar, N.U.; Stewart, G.D.; Prudich, M.E. [comps.] [Ohio Coal Research Center, Athens, OH (United States)

    1991-11-01T23:59:59.000Z

    Studies conducted at Ohio University and elsewhere have demonstrated that ultrafine aerosols, which have the highest surface area per unit mass, have enhanced potential to efficiently remove sulfur dioxide form combustion gases. Therefore it is proposed to generate a very fine aerosol calcium-rich sorbent (or similar aerosols) for gas conditioning. The aerosol will be generated by vaporization of the sorbent compound and subsequent homogeneous nucleation. In experimental studies liquids as well as solids will be converted into ultrafine aerosols by using suitable aerosol generator. The aerosol generator could be a simple bubbler or a flame spray jet using powders of calcium ``Compounds. Studies will then be carried out, to determine the dynamics of sulfur dioxide capture by the ultrafine aerosol. The primary objective of this research was to generate fine aerosols and to use them for coal combustion SO{sub 2}/NO{sub x} gas removal purposes. From the background study on the dry scrubbing system, it can be concluded that the most important experimental parameters are addition ratio, reactor temperature, residence time, total inlet flow rate and inlet SO{sub 2} concentration. Addition ratio is the inlet molar ratio of calcium to sulfur. Before any experimentation, it was necessary to decide and investigate the values of each of the parameters. Each of these parameters were investigated individually and the effects on SO{sub 2} removal were determined.

  19. Passive microwave observations of mesoscale convective systems over the tropical Pacific Ocean

    E-Print Network [OSTI]

    McGaughey, Gary Rae

    1994-01-01T23:59:59.000Z

    This paper presents high resolution passive microwave measurements obtained in the western Pacific warm pool region. These measurements represent the first comprehensive observations of convection over the tropical oceans, and were obtained from...

  20. A shrouded probe aerosol sampling cyclone

    E-Print Network [OSTI]

    Little, Stewart Craig

    1992-01-01T23:59:59.000Z

    AED at three different flow rates. The results would then be interpolated to give the needed flow rate value. The collection efficiency of the cyclone was characterized by the approach of generating liquid aerosols containing an analytical tracer... was neutralized by passing the aerosol flow through a chamber which contained a 10 mCi krypton 85 line source. Aerosol size produced by this apparatus depends on the concentration of the non-volatile solute, the size of the orifice, and the frequency applied...

  1. Aerosol composition, chemistry, and source characterization during the 2008 VOCALS Experiment

    SciTech Connect (OSTI)

    Lee, Y.; Springston, S.; Jayne, J.; Wang, J.; Senum, G.; Hubbe, J.; Alexander, L.; Brioude, J.; Spak, S.; Mena-Carrasco, M.; Kleinman, L.; Daum, P.

    2010-03-15T23:59:59.000Z

    Chemical composition of fine aerosol particles over the northern Chilean coastal waters was determined onboard the U.S. DOE G-1 aircraft during the VOCALS (VAMOS Ocean-Cloud-Atmosphere-Land Study) field campaign between October 16 and November 15, 2008. SO42-, NO3-, NH4+, and total organics (Org) were determined using an Aerodyne Aerosol Mass Spectrometer, and SO42-, NO3-, NH4+, Na+, Cl-, CH3SO3-, Mg2+, Ca2+, and K+ were determined using a particle-into-liquid sampler-ion chromatography technique. The results show the marine boundary layer (MBL) aerosol mass was dominated by non- sea-salt SO42- followed by Na+, Cl-, Org, NO3-, and NH4+, in decreasing importance; CH3SO3-, Ca2+, and K+ rarely exceeded their respective limits of detection. The SO42- aerosols were strongly acidic as the equivalent NH4+ to SO42- ratio was only {approx}0.25 on average. NaCl particles, presumably of sea-salt origin, showed chloride deficits but retained Cl- typically more than half the equivalency of Na+, and are externally mixed with the acidic sulfate aerosols. Nitrate was observed only on sea-salt particles, consistent with adsorption of HNO3 on sea-salt aerosols, responsible for the Cl- deficit. Dust particles appeared to play a minor role, judging from the small volume differences between that derived from the observed mass concentrations and that calculated based on particle size distributions. Because SO42- concentrations were substantial ({approx}0.5 - {approx}3 {micro}g/m3) with a strong gradient (highest near the shore), and the ocean-emitted dimethylsulfide and its unique oxidation product, CH3SO3-, were very low (i.e., {le} 40 parts per trillion and <0.05 {micro}g/m3, respectively), the observed SO42- aerosols are believed to be primarily of terrestrial origin. Back trajectory calculations indicate sulfur emissions from smelters and power plants along coastal regions of Peru and Chile are the main sources of these SO4- aerosols. However, compared to observations, model calculations appeared to underestimate sulfate concentrations based on an existing emission inventory. The agreement between observations and model predictions of CO as well as total sulfur is reexamined in this work with a new emission inventory made available recently.

  2. A simplified model of aerosol removal by containment sprays

    SciTech Connect (OSTI)

    Powers, D.A. (Sandia National Labs., Albuquerque, NM (United States)); Burson, S.B. (Nuclear Regulatory Commission, Washington, DC (United States). Div. of Safety Issue Resolution)

    1993-06-01T23:59:59.000Z

    Spray systems in nuclear reactor containments are described. The scrubbing of aerosols from containment atmospheres by spray droplets is discussed. Uncertainties are identified in the prediction of spray performance when the sprays are used as a means for decontaminating containment atmospheres. A mechanistic model based on current knowledge of the physical phenomena involved in spray performance is developed. With this model, a quantitative uncertainty analysis of spray performance is conducted using a Monte Carlo method to sample 20 uncertain quantities related to phenomena of spray droplet behavior as well as the initial and boundary conditions expected to be associated with severe reactor accidents. Results of the uncertainty analysis are used to construct simplified expressions for spray decontamination coefficients. Two variables that affect aerosol capture by water droplets are not treated as uncertain; they are (1) [open quote]Q[close quote], spray water flux into the containment, and (2) [open quote]H[close quote], the total fall distance of spray droplets. The choice of values of these variables is left to the user since they are plant and accident specific. Also, they can usually be ascertained with some degree of certainty. The spray decontamination coefficients are found to be sufficiently dependent on the extent of decontamination that the fraction of the initial aerosol remaining in the atmosphere, m[sub f], is explicitly treated in the simplified expressions. The simplified expressions for the spray decontamination coefficient are given. Parametric values for these expressions are found for median, 10 percentile, and 90 percentile values in the uncertainty distribution for the spray decontamination coefficient. Examples are given to illustrate the utility of the simplified expressions to predict spray decontamination of an aerosol-laden atmosphere.

  3. Unintended consequences of atmospheric injection of sulphate aerosols.

    SciTech Connect (OSTI)

    Brady, Patrick Vane; Kobos, Peter Holmes; Goldstein, Barry

    2010-10-01T23:59:59.000Z

    Most climate scientists believe that climate geoengineering is best considered as a potential complement to the mitigation of CO{sub 2} emissions, rather than as an alternative to it. Strong mitigation could achieve the equivalent of up to -4Wm{sup -2} radiative forcing on the century timescale, relative to a worst case scenario for rising CO{sub 2}. However, to tackle the remaining 3Wm{sup -2}, which are likely even in a best case scenario of strongly mitigated CO{sub 2} releases, a number of geoengineering options show promise. Injecting stratospheric aerosols is one of the least expensive and, potentially, most effective approaches and for that reason an examination of the possible unintended consequences of the implementation of atmospheric injections of sulphate aerosols was made. Chief among these are: reductions in rainfall, slowing of atmospheric ozone rebound, and differential changes in weather patterns. At the same time, there will be an increase in plant productivity. Lastly, because atmospheric sulphate injection would not mitigate ocean acidification, another side effect of fossil fuel burning, it would provide only a partial solution. Future research should aim at ameliorating the possible negative unintended consequences of atmospheric injections of sulphate injection. This might include modeling the optimum rate and particle type and size of aerosol injection, as well as the latitudinal, longitudinal and altitude of injection sites, to balance radiative forcing to decrease negative regional impacts. Similarly, future research might include modeling the optimum rate of decrease and location of injection sites to be closed to reduce or slow rapid warming upon aerosol injection cessation. A fruitful area for future research might be system modeling to enhance the possible positive increases in agricultural productivity. All such modeling must be supported by data collection and laboratory and field testing to enable iterative modeling to increase the accuracy and precision of the models, while reducing epistemic uncertainties.

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

    SciTech Connect (OSTI)

    Richard A. Ferrare; David D. Turner

    2011-09-01T23:59:59.000Z

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

  5. On the validity of the Poisson assumption in sampling nanometer-sized aerosols

    SciTech Connect (OSTI)

    Damit, Brian E [ORNL] [ORNL; Wu, Dr. Chang-Yu [University of Florida, Gainesville] [University of Florida, Gainesville; Cheng, Mengdawn [ORNL] [ORNL

    2014-01-01T23:59:59.000Z

    A Poisson process is traditionally believed to apply to the sampling of aerosols. For a constant aerosol concentration, it is assumed that a Poisson process describes the fluctuation in the measured concentration because aerosols are stochastically distributed in space. Recent studies, however, have shown that sampling of micrometer-sized aerosols has non-Poissonian behavior with positive correlations. The validity of the Poisson assumption for nanometer-sized aerosols has not been examined and thus was tested in this study. Its validity was tested for four particle sizes - 10 nm, 25 nm, 50 nm and 100 nm - by sampling from indoor air with a DMA- CPC setup to obtain a time series of particle counts. Five metrics were calculated from the data: pair-correlation function (PCF), time-averaged PCF, coefficient of variation, probability of measuring a concentration at least 25% greater than average, and posterior distributions from Bayesian inference. To identify departures from Poissonian behavior, these metrics were also calculated for 1,000 computer-generated Poisson time series with the same mean as the experimental data. For nearly all comparisons, the experimental data fell within the range of 80% of the Poisson-simulation values. Essentially, the metrics for the experimental data were indistinguishable from a simulated Poisson process. The greater influence of Brownian motion for nanometer-sized aerosols may explain the Poissonian behavior observed for smaller aerosols. Although the Poisson assumption was found to be valid in this study, it must be carefully applied as the results here do not definitively prove applicability in all sampling situations.

  6. Spent fuel sabotage aerosol ratio program : FY 2004 test and data summary.

    SciTech Connect (OSTI)

    Brucher, Wenzel (Gesellschaft fur Anlagen- und Reaktorsicherheit, Germany); Koch, Wolfgang (Fraunhofer Institut fur Toxikologie und Experimentelle Medizin, Germany); Pretzsch, Gunter Guido (Gesellschaft fur Anlagen- und Reaktorsicherheit, Germany); Loiseau, Olivier (Institut de Radioprotection et de Surete Nucleaire, France); Mo, Tin (U.S. Nuclear Regulatory Commission, Washington, DC); Billone, Michael C. (Argonne National Laboratory, Argonne, IL); Autrusson, Bruno A. (Institut de Radioprotection et de Surete Nucleaire, France); Young, F. I. (U.S. Nuclear Regulatory Commission, Washington, DC); Coats, Richard Lee; Burtseva, Tatiana (Argonne National Laboratory, Argonne, IL); Luna, Robert Earl; Dickey, Roy R.; Sorenson, Ken Bryce; Nolte, Oliver (Fraunhofer Institut fur Toxikologie und Experimentelle Medizin, Germany); Thompson, Nancy Slater (U.S. Department of Energy, Washington, DC); Hibbs, Russell S. (U.S. Department of Energy, Washington, DC); Gregson, Michael Warren; Lange, Florentin (Gesellschaft fur Anlagen- und Reaktorsicherheit, Germany); Molecke, Martin Alan; Tsai, Han-Chung (Argonne National Laboratory, Argonne, IL)

    2005-07-01T23:59:59.000Z

    This multinational, multi-phase spent fuel sabotage test program is quantifying the aerosol particles produced when the products of a high energy density device (HEDD) interact with and explosively particulate test rodlets that contain pellets of either surrogate materials or actual spent fuel. This program has been underway for several years. This program provides data that are relevant to some sabotage scenarios in relation to spent fuel transport and storage casks, and associated risk assessments. The program also provides significant technical and political benefits in international cooperation. We are quantifying the Spent Fuel Ratio (SFR), the ratio of the aerosol particles released from HEDD-impacted actual spent fuel to the aerosol particles produced from surrogate materials, measured under closely matched test conditions, in a contained test chamber. In addition, we are measuring the amounts, nuclide content, size distribution of the released aerosol materials, and enhanced sorption of volatile fission product nuclides onto specific aerosol particle size fractions. These data are the input for follow-on modeling studies to quantify respirable hazards, associated radiological risk assessments, vulnerability assessments, and potential cask physical protection design modifications. This document includes an updated description of the test program and test components for all work and plans made, or revised, during FY 2004. It also serves as a program status report as of the end of FY 2004. All available test results, observations, and aerosol analyses plus interpretations--primarily for surrogate material Phase 2 tests, series 2/5A through 2/9B, using cerium oxide sintered ceramic pellets are included. Advanced plans and progress are described for upcoming tests with unirradiated, depleted uranium oxide and actual spent fuel test rodlets. This spent fuel sabotage--aerosol test program is coordinated with the international Working Group for Sabotage Concerns of Transport and Storage Casks (WGSTSC) and supported by both the U.S. Department of Energy and the Nuclear Regulatory Commission.

  7. Effect of aerosols and NO2 concentration on ultraviolet actinic flux near Mexico City during MILAGRO: Measurements and model calculations

    SciTech Connect (OSTI)

    Palancar, Gustavo G.; Lefer, Barry; Hall, Samual R.; Shaw, William J.; Corr, Chelsea A.; Herndon, Scott C.; Slusser, J. R.; Madronich, Sasha

    2013-01-24T23:59:59.000Z

    Ultraviolet (UV) actinic ?uxes (AF) measured with three Scanning Actinic Flux Spectroradiometers (SAFS) are compared with the Tropospheric Ultraviolet-Visible (TUV) model v.5 in order to assess the effects of aerosols and NO2 concentrations on the radiation. Measurements were made during the MILAGRO campaign near Mexico City in March 2006, at a ground-based station near Mexico City (the T1 supersite) and from the NSF/NCAR C-130 aircraft. At the surface, measurements are typically smaller by up to 25 % in the morning, 10% at noon, and 40% in the afternoon, than actinic flux modeled for clean, cloud-free conditions. When measurements of PBL height, NO2 concentration and aerosols optical properties are included in the model, the agreement improves to within ±10% in the morning and afternoon, and ±3% at noon. Based on daily averages, aerosols account for 68%, NO2 for 25%, and residual uncertainties for 7% of these AF reductions observed at the surface. Several overpasses from the C-130 aircraft provided the opportunity to examine the actinic flux perturbations aloft, and also show better agreement with the model when aerosol and NO2 effects are included above and below the flight altitude. TUV model simulations show that the vertical structure of the actinic flux is sensitive to the choice of the aerosol single scattering albedo (SSA) at UV wavelengths. Typically, aerosols caused enhanced AF above the PBL and reduced AF near the surface. However, for highly scattering aerosols (SSA > 0.95), enhancements can penetrate well into the PBL, while for strongly absorbing aerosols (SSA<0.7) reductions in AF are computed in the free troposphere as well as in the PBL. Additional measurements of the SSA at these wavelengths are needed to better constrain the effect of aerosols on the vertical structure of the actinic flux.

  8. TRANSIT TIMING OBSERVATIONS FROM KEPLER. VI. POTENTIALLY INTERESTING CANDIDATE SYSTEMS FROM FOURIER-BASED STATISTICAL TESTS

    SciTech Connect (OSTI)

    Steffen, Jason H. [Fermilab Center for Particle Astrophysics, P.O. Box 500, MS 127, Batavia, IL 60510 (United States); Ford, Eric B. [Astronomy Department, University of Florida, 211 Bryant Space Sciences Center, Gainesville, FL 32111 (United States); Rowe, Jason F.; Borucki, William J.; Bryson, Steve; Caldwell, Douglas A.; Jenkins, Jon M.; Koch, David G.; Sanderfer, Dwight T.; Seader, Shawn; Twicken, Joseph D. [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Fabrycky, Daniel C. [UCO/Lick Observatory, University of California, Santa Cruz, CA 95064 (United States); Holman, Matthew J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Welsh, William F. [Astronomy Department, San Diego State University, San Diego, CA 92182-1221 (United States); Batalha, Natalie M. [Department of Physics and Astronomy, San Jose State University, San Jose, CA 95192 (United States); Ciardi, David R. [NASA Exoplanet Science Institute/California Institute of Technology, Pasadena, CA 91125 (United States); Kjeldsen, Hans [Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C (Denmark); Prsa, Andrej, E-mail: jsteffen@fnal.gov [Department of Astronomy and Astrophysics, Villanova University, 800 East Lancaster Avenue, Villanova, PA 19085 (United States)

    2012-09-10T23:59:59.000Z

    We analyze the deviations of transit times from a linear ephemeris for the Kepler Objects of Interest (KOI) through quarter six of science data. We conduct two statistical tests for all KOIs and a related statistical test for all pairs of KOIs in multi-transiting systems. These tests identify several systems which show potentially interesting transit timing variations (TTVs). Strong TTV systems have been valuable for the confirmation of planets and their mass measurements. Many of the systems identified in this study should prove fruitful for detailed TTV studies.

  9. LINEAR SYSTEMS WITH SIGN-OBSERVATIONS RENEE KOPLON AND EDUARDO D. SONTAG

    E-Print Network [OSTI]

    Sontag, Eduardo

    relatively simple systems. However, for large-scale problems, controllers resulting from the application, various types of switching controllers, and humans ­or, more re- cently, expert systems,­ in supervisory the interplay of modern control theory with automata theory and other techniques from computer science

  10. Observations of prolific transient luminous event production above a mesoscale convective system in Argentina during

    E-Print Network [OSTI]

    Thomas, Jeremy N.

    in Argentina during the Sprite2006 Campaign in Brazil F. T. São Sabbas,1 M. J. Taylor,2 P.D. Pautet,2 M. Bailey convective system (MCS) over Argentina, as part of the third sprite campaign in Brazil. GOES infrared (IR a mesoscale convective system in Argentina during the Sprite2006 Campaign in Brazil, J. Geophys. Res., 115, A

  11. ARM - Field Campaign - Aerosol Lidar Validation Experiment - ALIVE

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del(ANL-IN-03-032)8Li (59AJ76)ARM2, 2006ObservationsInfraredgovCampaignsAerosol Lidar

  12. ARM - Field Campaign - Aerosol Life Cycle IOP at BNL

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del(ANL-IN-03-032)8Li (59AJ76)ARM2, 2006ObservationsInfraredgovCampaignsAerosol

  13. Effective Henry's Law Partitioning and the Salting Constant of Glyoxal in Aerosols Containing Sulfate

    E-Print Network [OSTI]

    .g. oxalic acid or pyruvic acid) have been observed.26-30 Glyoxal uptake into a dilute aqueous phase ammonium sulfate/fulvic acid (AS/FA) seed aerosols both show an exponential increase of effective Henry-sulfate for- mation9,13,14 and the irreversible oxidation by OH radicals yielding carboxylic acids (e

  14. In-flight degradation correction of SCIAMACHY UV reflectances and Absorbing Aerosol Index

    E-Print Network [OSTI]

    Stoffelen, Ad

    In-flight degradation correction of SCIAMACHY UV reflectances and Absorbing Aerosol Index L. G) derived from the observed Earth reflectance. Instrument degradation of the Scanning Imaging Absorption mean should be more or less constant when instrument degradation is absent. The analysis reveals

  15. Where Are Aerosol-Cloud Albedo Effects? Muelmenstaedt et al., 2013

    E-Print Network [OSTI]

    Russell, Lynn

    particles. Wave Breaking ! Bubble Bursting Observed Aerosol Effects on Marine Cloud Nucleation with particles? #12;2/11/14 2 "Dissolved" Organic Matter is Measured in Filtered Seawater as Organic Carbon (OC) P. Verdugo, 2011 Par$culate Organic Carbon Dissolved Organic Carbon POC

  16. Three-dimensional simulations of inorganic aerosol distributions in east Asia during spring 2001

    E-Print Network [OSTI]

    conditions of low dust loading, SO2 condensation and gas phase ammonia distribution determine the nitrate includes the on-line gas-aerosol thermodynamic module SCAPE II, and explicitly considers chemical aging of dust, is used in the analysis. The model is found to represent many of the important observed features

  17. Particle size limits for quantitative aerosol analysis using laser-induced breakdown spectroscopy: Temporal considerations

    E-Print Network [OSTI]

    Hahn, David W.

    dissociation, vaporization and linear analyte response of an individual particle suspended in a gas stream individual silica microspheres in an aerosolized air stream was investigated using laser-induced breakdown of analyte signals for the 2.47 and 4.09-micrometer particles was observed to be approximately constant

  18. Aerosol Best Estimate Value-Added Product

    SciTech Connect (OSTI)

    Flynn, C; Turner, D; Koontz, A; Chand, D; Sivaraman, C

    2012-07-19T23:59:59.000Z

    The objective of the Aerosol Best Estimate (AEROSOLBE) value-added product (VAP) is to provide vertical profiles of aerosol extinction, single scatter albedo, asymmetry parameter, and Angstroem exponents for the atmospheric column above the Central Facility at the ARM Southern Great Plains (SGP) site. We expect that AEROSOLBE will provide nearly continuous estimates of aerosol optical properties under a range of conditions (clear, broken clouds, overcast clouds, etc.). The primary requirement of this VAP was to provide an aerosol data set as continuous as possible in both time and height for the Broadband Heating Rate Profile (BBHRP) VAP in order to provide a structure for the comprehensive assessment of our ability to model atmospheric radiative transfer for all conditions. Even though BBHRP has been completed, AEROSOLBE results are very valuable for environmental, atmospheric, and climate research.

  19. 5, 90399063, 2005 Arctic aerosol effect

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Radiation Measurement (ARM) data, we find surface cloud radiative forcing (SCRF) is -22 W/m 2 for shortwave. If aerosols are taken into account, the SCRF has been increased during winter while15 negative SCRF has been

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

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

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

  1. The Earth Observing System (EOS)Aura satellite mission is scheduled to launch in June 2004.

    E-Print Network [OSTI]

    ://cloudsat.atmos.colostate.edu/),which is to be launched in mid-2005 [Stephens et al.,2002]. This group of satellites,including the Centre National d? Total Ozone Mapping Spectrometer (TOMS) observations from 1978 show a strong secular decrease in column the TOMS/SBUV global column and profile ozone trend measurements. What are the sources and processes

  2. Electrically Driven Technologies for Radioactive Aerosol Abatement

    SciTech Connect (OSTI)

    David W. DePaoli; Ofodike A. Ezekoye; Costas Tsouris; Valmor F. de Almeida

    2003-01-28T23:59:59.000Z

    The purpose of this research project was to develop an improved understanding of how electriexecy driven processes, including electrocoalescence, acoustic agglomeration, and electric filtration, may be employed to efficiently treat problems caused by the formation of aerosols during DOE waste treatment operations. The production of aerosols during treatment and retrieval operations in radioactive waste tanks and during thermal treatment operations such as calcination presents a significant problem of cost, worker exposure, potential for release, and increased waste volume.

  3. Apparatus for sampling and characterizing aerosols

    DOE Patents [OSTI]

    Dunn, P.F.; Herceg, J.E.; Klocksieben, R.H.

    1984-04-11T23:59:59.000Z

    Apparatus for sampling and characterizing aerosols having a wide particle size range at relatively low velocities may comprise a chamber having an inlet and an outlet, the chamber including: a plurality of vertically stacked, successive particle collection stages; each collection stage includes a separator plate and a channel guide mounted transverse to the separator plate, defining a labyrinthine flow path across the collection stage. An opening in each separator plate provides a path for the aerosols from one collection stage t

  4. Aerosol fabrication methods for monodisperse nanoparticles

    DOE Patents [OSTI]

    Jiang, Xingmao; Brinker, C Jeffrey

    2014-10-21T23:59:59.000Z

    Exemplary embodiments provide materials and methods for forming monodisperse particles. In one embodiment, the monodisperse particles can be formed by first spraying a nanoparticle-containing dispersion into aerosol droplets and then heating the aerosol droplets in the presence of a shell precursor to form core-shell particles. By removing either the shell layer or the nanoparticle core of the core-shell particles, monodisperse nanoparticles can be formed.

  5. Study for radionuclide transfer ratio of aerosols generated during heat cutting

    SciTech Connect (OSTI)

    Iguchi, Yukihiro; Baba, Tsutomu; Kawakami, Hiroto [Japan Nuclear Energy Safety Organization - JNES (Japan); Kitahara, Takashi; Watanabe, Atsushi [Hitachi, Ltd. (Japan); Kodama, Mitsuhiro [Nippon Nuclear Fuel Development Co., Ltd. (Japan)

    2007-07-01T23:59:59.000Z

    The metallic elements with a low melting point and high vapor pressure seemed to transfer in aerosols selectively at dismantling reactor internals using heat cutting. Therefore, the arc melting tests of neutron irradiated zirconium alloy were conducted to investigate the radionuclide transfer behavior of aerosols generated during the heat cutting of activated metals. The arc melting test was conducted using a tungsten inert gas welding machine in an inert gas or air atmosphere. The radioactive aerosols were collected by filter and charcoal filter. The test sample was obtained from Zry-2 fuel cladding irradiated in a Japanese boiling water reactor for five fuel cycles. The activity analysis, chemical composition measurement and scanning electron microscope observation of aerosols were carried out. Some radionuclides were enriched in the aerosols generated in an inert gas atmosphere and the radionuclide transfer ratio did not change remarkably by the presence of air. The transfer ratio of Sb-125 was almost the same as that of Co-60. It was expected that Sb-125 was enriched from other elements since Sb is an element with a low melting point and high vapor pressure compared with the base metal (Zr). In the viewpoint of the environmental impact assessment, it became clear that the influence if Sb-125 is comparable to Co-60. The transfer ratio of Mn-54 was one order higher compared with other radionuclides. The results were discussed on the basis of thermal properties and oxide formation energy of the metallic elements. (authors)

  6. SST subseasonal variability in the central Benguela upwelling system as inferred from satellite observations (19992009)

    E-Print Network [OSTI]

    Boyer, Edmond

    associated with the eastern flank of the semipermanent South Atlantic Anti- cyclone (SAA). Through Ekman of distinct physical and biological features, the Benguela system can be separated into three zones charac

  7. Observations on A Technology Roadmap for Generation IV Nuclear Energy Systems: Technical Roadmap Report

    Broader source: Energy.gov [DOE]

    The development of advanced nuclear energy systems in the U.S. will depend greatly on the continued success of currently operating light water nuclear power plants and the ordering of new...

  8. Dual-Doppler observations of the formative stage of an asymmetric squall line system

    E-Print Network [OSTI]

    Jamieson, Daniel Richard

    2002-01-01T23:59:59.000Z

    The objective of this study is to document and explain the formation of a large asymmetric squall line system. Despite having a precipitation pattern similar to the conceptual model of an asymmetric squall line, the development and evolution...

  9. Experimental observation of a phase transition in the evolution of many-body systems with dipolar interactions

    E-Print Network [OSTI]

    Gonzalo A. Alvarez; Dieter Suter; Robin Kaiser

    2014-09-16T23:59:59.000Z

    Non-equilibrium dynamics of many-body systems is important in many branches of science, such as condensed matter, quantum chemistry, and ultracold atoms. Here we report the experimental observation of a phase transition of the quantum coherent dynamics of a 3D many-spin system with dipolar interactions, and determine its critical exponents. Using nuclear magnetic resonance (NMR) on a solid-state system of spins at room-temperature, we quench the interaction Hamiltonian to drive the evolution of the system. The resulting dynamics of the system coherence can be localized or extended, depending on the quench strength. Applying a finite-time scaling analysis to the observed time-evolution of the number of correlated spins, we extract the critical exponents v = s = 0.42 around the phase transition separating a localized from a delocalized dynamical regime. These results show clearly that such nuclear-spin based quantum simulations can effectively model the non-equilibrium dynamics of complex many-body systems, such as 3D spin-networks with dipolar interactions.

  10. aerosol properties in-canopy: Topics by E-print Network

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

    aerosol, cloud condensation nuclei, water accommodation coefficient, organic of aerosol size distribution, chemical composition and cloud condensation nuclei (CCN) concentration...

  11. Optical, physical, and chemical properties of springtime aerosol over Barrow Alaska in 2008

    SciTech Connect (OSTI)

    Shantz, Nicole C.; Gultepe, Ismail; Andrews, Elisabeth; Zelenyuk, Alla; Earle, Michael; MacDonald, A. M.; Liu, Peter S.; Leaitch, W. R.

    2014-03-06T23:59:59.000Z

    Airborne observations from four flights during the 2008 Indirect and Semi-Direct Aerosol Campaign (ISDAC) are used to examine some cloud-free optical, physical, and chemical properties of aerosol particles in the springtime Arctic troposphere. The number concentrations of particles larger than 0.12 ?m (Na>120), important for light extinction and cloud droplet formation, ranged from 15 to 2260 cm?3, with the higher Na>120 cases dominated by measurements from two flights of long-range transported biomass burning (BB) aerosols. The two other flights examined here document a relatively clean aerosol and an Arctic Haze aerosol impacted by larger particles largely composed of dust. For observations from the cleaner case and the BB cases, the particle light scattering coefficients at low relative humidity (RH<20%) increased nonlinearly with increasing Na>120, driven mostly by an increase in mean sizes of particles with increasing Na>120 (BB cases). For those three cases, particle light absorption coefficients also increased nonlinearly with increasing Na>120 and linearly with increasing submicron particle volume concentration. In addition to black carbon, brown carbon was estimated to have increased light absorption coefficients by 27% (450 nm wavelength) and 14% (550 nm) in the BB cases. For the case with strong dust influence, the absorption relative to submicron particle volume was small compared with the other cases. There was a slight gradient of Passive Cavity Aerosol Spectrometer Probe (PCASP) mean volume diameter (MVD) towards smaller sizes with increasing height, which suggests more scavenging of the more elevated particles, consistent with a typically longer lifetime of particles higher in the atmosphere. However, in approximately 10% of the cases, the MVD increased (>0.4 ?m) with increasing altitude, suggesting transport of larger fine particle mass (possibly coarse particle mass) at high levels over the Arctic. This may be because of transport of larger particles at higher elevations and relatively slow deposition to the surface.

  12. AEROSOL CHEMICAL COMPOSITION CHARACTERIZATION AT THE ARM SOUTHERN GREAT PLAINS (SGP) SITE USING AN AEROSOL CHEMICAL

    E-Print Network [OSTI]

    AEROSOL CHEMICAL COMPOSITION CHARACTERIZATION AT THE ARM SOUTHERN GREAT PLAINS (SGP) SITE USING AN AEROSOL CHEMICAL SPECIATION MONITOR Yin-Nan Lee1 , Fan Mei1 , Stephanie DeJong1 , Anne Jefferson2 1 Atmospheric Sciences Division, Brookhaven National Lab, Upton, NY 2 CIRES, University of Colorado, Boulder, CO

  13. Direct and semidirect aerosol effects of southern African biomass burning aerosol

    E-Print Network [OSTI]

    Wood, Robert

    radiative effects associated with increased low cloud cover dominate over a weaker positive allsky direct 2011; published 21 June 2011. [1] Direct and semidirect radiative effects of biomass burning aerosols radiative effect (DRE). In contrast, over the land where the aerosols are often below or within cloud layers

  14. Nonlinear Observer Design for Interconnected Power Systems M. A. Mahmud, Student Member, IEEE, M. J. Hossain, Member, IEEE, and H. R. Pota

    E-Print Network [OSTI]

    Pota, Himanshu Roy

    Nonlinear Observer Design for Interconnected Power Systems M. A. Mahmud, Student Member, IEEE, M. J design method for interconnected power systems. The concepts of nonlinear coordinate transformation, Lie derivative, and relative degree are used to design the observer for power systems. In this proposed design

  15. TRANSIT TIMING OBSERVATIONS FROM KEPLER. IV. CONFIRMATION OF FOUR MULTIPLE-PLANET SYSTEMS BY SIMPLE PHYSICAL MODELS

    SciTech Connect (OSTI)

    Fabrycky, Daniel C. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, Santa Cruz, CA 95064 (United States); Ford, Eric B.; Moorhead, Althea V. [Astronomy Department, University of Florida, 211 Bryant Space Sciences Center, Gainesville, FL 32111 (United States); Steffen, Jason H. [Fermilab Center for Particle Astrophysics, P.O. Box 500, MS 127, Batavia, IL 60510 (United States); Rowe, Jason F.; Christiansen, Jessie L. [SETI Institute, Mountain View, CA 94043 (United States); Carter, Joshua A.; Fressin, Francois; Geary, John [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Batalha, Natalie M. [Department of Physics and Astronomy, San Jose State University, San Jose, CA 95192 (United States); Borucki, William J.; Bryson, Steve; Haas, Michael R. [NASA Ames Research Center, Moffett Field, CA, 94035 (United States); Buchhave, Lars A. [Department of Astrophysics and Planetary Science, Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen (Denmark); Ciardi, David R. [NASA Exoplanet Science Institute/Caltech, Pasadena, CA 91126 (United States); Cochran, William D.; Endl, Michael [McDonald Observatory, The University of Texas, Austin TX 78730 (United States); Fanelli, Michael N. [Bay Area Environmental Research Institute/NASA Ames Research Center, Moffett Field, CA 94035 (United States); Fischer, Debra [Astronomy Department, Yale University, New Haven, CT (United States); Hall, Jennifer R., E-mail: daniel.fabrycky@gmail.com [Orbital Sciences Corporation/NASA Ames Research Center, Moffett Field, CA 94035 (United States); and others

    2012-05-10T23:59:59.000Z

    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 four sets of light curves from the Kepler spacecraft, each which of shows multiple planets transiting the same star. Departure of the timing of these transits from strict periodicity indicates that 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.

  16. This chapter describes observations of continuing change in the Arctic environmental system. It is or-

    E-Print Network [OSTI]

    Bhatt, Uma

    for the longest period and largest area of ice sheet melt since at least 1978, and the highest melt rate since in the Canadian Arctic, where the rate of mass loss from small glaciers and ice caps continued to increase system. It is or- ganized into five broad sections: atmosphere, ocean, sea ice cover, land, and Greenland

  17. An adaptive observer for hyperbolic systems with application to UnderBalanced

    E-Print Network [OSTI]

    Boyer, Edmond

    an UnderBalanced well. While a well is being drilled, a fluid circulates through the drilling system. The drilling fluid cools down the drillbit, and evacuates rock cuttings. More importantly, it pressurizes fluid is controlled by a valve, which enables tighter control of the pressure. UnderBalanced Drilling

  18. Observation and characterization of chimera states in coupled dynamical systems with nonlocal coupling

    E-Print Network [OSTI]

    R. Gopal; V. K. Chandrasekar; A. Venkatesan; M. Lakshmanan

    2014-05-15T23:59:59.000Z

    By developing the concepts of strength of incoherence and discontinuity measure, we show that a distinct quantitative characterization of chimera and multichimera states which occur in networks of coupled nonlinear dynamical systems admitting nonlocal interactions of finite radius can be made. These measures also clearly distinguish between chimera or multichimera states (both stable and breathing types) and coherent and incoherent as well as cluster states....

  19. UV Habitability of Possible Exomoons in Observed F-star Planetary Systems

    E-Print Network [OSTI]

    Sato, Satoko

    2015-01-01T23:59:59.000Z

    In the present study we explore the astrobiological significance of F-type stars of spectral type between F5 V and F9.5 V, which possess Jupiter-type planets within or close to their climatological habitable zones. These planets, or at least a subset of them, may also possess rocky exomoons, which potentially offer habitable environments. Our work considers eight selected systems. The Jupiter-type planets in these systems are in notably different orbits with eccentricities ranging from 0.08 to 0.72. Particularly, we consider the stellar UV environments provided by the photospheric stellar radiation in regard to the circumstellar habitability of the system. According to previous studies, DNA is taken as a proxy for carbon-based macromolecules following the paradigm that extraterrestrial biology might be based on hydrocarbons. Thus, the DNA action spectrum is utilized to represent the impact of the stellar UV radiation. Atmospheric attenuation is taken into account based on parameterized attenuation functions. ...

  20. TRANSIT TIMING OBSERVATIONS FROM KEPLER. II. CONFIRMATION OF TWO MULTIPLANET SYSTEMS VIA A NON-PARAMETRIC CORRELATION ANALYSIS

    SciTech Connect (OSTI)

    Ford, Eric B.; Moorhead, Althea V.; Morehead, Robert C. [Astronomy Department, University of Florida, 211 Bryant Space Sciences Center, Gainesville, FL 32611 (United States); Fabrycky, Daniel C. [UCO/Lick Observatory, University of California, Santa Cruz, CA 95064 (United States); Steffen, Jason H. [Fermilab Center for Particle Astrophysics, P.O. Box 500, MS 127, Batavia, IL 60510 (United States); Carter, Joshua A.; Fressin, Francois; Holman, Matthew J.; Ragozzine, Darin; Charbonneau, David [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Lissauer, Jack J.; Rowe, Jason F.; Borucki, William J.; Bryson, Stephen T.; Burke, Christopher J.; Caldwell, Douglas A. [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Welsh, William F. [Astronomy Department, San Diego State University, San Diego, CA 92182-1221 (United States); Allen, Christopher [Orbital Sciences Corporation/NASA Ames Research Center, Moffett Field, CA 94035 (United States); Batalha, Natalie M. [Department of Physics and Astronomy, San Jose State University, San Jose, CA 95192 (United States); Buchhave, Lars A., E-mail: eford@astro.ufl.edu [Niels Bohr Institute, Copenhagen University, DK-2100 Copenhagen (Denmark); Collaboration: Kepler Science Team; and others

    2012-05-10T23:59:59.000Z

    We present a new method for confirming transiting planets based on the combination of transit timing variations (TTVs) and dynamical stability. Correlated TTVs provide evidence that the pair of bodies is in the same physical system. Orbital stability provides upper limits for the masses of the transiting companions that are in the planetary regime. This paper describes a non-parametric technique for quantifying the statistical significance of TTVs based on the correlation of two TTV data sets. We apply this method to an analysis of the TTVs of two stars with multiple transiting planet candidates identified by Kepler. We confirm four transiting planets in two multiple-planet systems based on their TTVs and the constraints imposed by dynamical stability. An additional three candidates in these same systems are not confirmed as planets, but are likely to be validated as real planets once further observations and analyses are possible. If all were confirmed, these systems would be near 4:6:9 and 2:4:6:9 period commensurabilities. Our results demonstrate that TTVs provide a powerful tool for confirming transiting planets, including low-mass planets and planets around faint stars for which Doppler follow-up is not practical with existing facilities. Continued Kepler observations will dramatically improve the constraints on the planet masses and orbits and provide sensitivity for detecting additional non-transiting planets. If Kepler observations were extended to eight years, then a similar analysis could likely confirm systems with multiple closely spaced, small transiting planets in or near the habitable zone of solar-type stars.

  1. Transit Timing Observations from Kepler: II. Confirmation of Two Multiplanet Systems via a Non-parametric Correlation Analysis

    SciTech Connect (OSTI)

    Ford, Eric B.; /Florida U.; Fabrycky, Daniel C.; /Lick Observ.; Steffen, Jason H.; /Fermilab; Carter, Joshua A.; /Harvard-Smithsonian Ctr. Astrophys.; Fressin, Francois; /Harvard-Smithsonian Ctr. Astrophys.; Holman, Matthew J.; /Harvard-Smithsonian Ctr. Astrophys.; Lissauer, Jack J.; /NASA, Ames; Moorhead, Althea V.; /Florida U.; Morehead, Robert C.; /Florida U.; Ragozzine, Darin; /Harvard-Smithsonian Ctr. Astrophys.; Rowe, Jason F.; /NASA, Ames /SETI Inst., Mtn. View /San Diego State U., Astron. Dept.

    2012-01-01T23:59:59.000Z

    We present a new method for confirming transiting planets based on the combination of transit timing variations (TTVs) and dynamical stability. Correlated TTVs provide evidence that the pair of bodies are in the same physical system. Orbital stability provides upper limits for the masses of the transiting companions that are in the planetary regime. This paper describes a non-parametric technique for quantifying the statistical significance of TTVs based on the correlation of two TTV data sets. We apply this method to an analysis of the transit timing variations of two stars with multiple transiting planet candidates identified by Kepler. We confirm four transiting planets in two multiple planet systems based on their TTVs and the constraints imposed by dynamical stability. An additional three candidates in these same systems are not confirmed as planets, but are likely to be validated as real planets once further observations and analyses are possible. If all were confirmed, these systems would be near 4:6:9 and 2:4:6:9 period commensurabilities. Our results demonstrate that TTVs provide a powerful tool for confirming transiting planets, including low-mass planets and planets around faint stars for which Doppler follow-up is not practical with existing facilities. Continued Kepler observations will dramatically improve the constraints on the planet masses and orbits and provide sensitivity for detecting additional non-transiting planets. If Kepler observations were extended to eight years, then a similar analysis could likely confirm systems with multiple closely spaced, small transiting planets in or near the habitable zone of solar-type stars.

  2. Aerosol characterization study using multi-spectrum remote sensing measurement techniques.

    SciTech Connect (OSTI)

    Glen, Crystal Chanea; Sanchez, Andres L.; Lucero, Gabriel Anthony; Schmitt, Randal L.; Johnson, Mark S.; Tezak, Matthew Stephen; Servantes, Brandon Lee

    2013-09-01T23:59:59.000Z

    A unique aerosol flow chamber coupled with a bistatic LIDAR system was implemented to measure the optical scattering cross sections and depolarization ratio of common atmospheric particulates. Each of seven particle types (ammonium sulfate, ammonium nitrate, sodium chloride, potassium chloride, black carbon and Arizona road dust) was aged by three anthropogenically relevant mechanisms: 1. Sulfuric acid deposition, 2. Toluene ozonolysis reactions, and 3. m-Xylene ozonolysis reactions. The results of pure particle scattering properties were compared with their aged equivalents. Results show that as most particles age under industrial plume conditions, their scattering cross sections are similar to pure black carbon, which has significant impacts to our understanding of aerosol impacts on climate. In addition, evidence emerges that suggest chloride-containing aerosols are chemically altered during the organic aging process. Here we present the direct measured scattering cross section and depolarization ratios for pure and aged atmospheric particulates.

  3. Results and code predictions for ABCOVE (aerosol behavior code validation and evaluation) aerosol code validation: Test AB6 with two aerosol species. [LMFBR

    SciTech Connect (OSTI)

    Hilliard, R K; McCormack, J C; Muhlestein, L D

    1984-12-01T23:59:59.000Z

    A program for aerosol behavior code validation and evaluation (ABCOVE) has been developed in accordance with the LMFBR Safety Program Plan. The ABCOVE program is a cooperative effort between the USDOE, the USNRC, and their contractor organizations currently involved in aerosol code development, testing or application. The second large-scale test in the ABCOVE program, AB6, was performed in the 850-m/sup 3/ CSTF vessel with a two-species test aerosol. The test conditions simulated the release of a fission product aerosol, NaI, in the presence of a sodium spray fire. Five organizations made pretest predictions of aerosol behavior using seven computer codes. Three of the codes (QUICKM, MAEROS and CONTAIN) were discrete, multiple species codes, while four (HAA-3, HAA-4, HAARM-3 and SOFIA) were log-normal codes which assume uniform coagglomeration of different aerosol species. Detailed test results are presented and compared with the code predictions for seven key aerosol behavior parameters.

  4. Aerosol beam-focus laser-induced plasma spectrometer device

    DOE Patents [OSTI]

    Cheng, Meng-Dawn (Oak Ridge, TN)

    2002-01-01T23:59:59.000Z

    An apparatus for detecting elements in an aerosol includes an aerosol beam focuser for concentrating aerosol into an aerosol beam; a laser for directing a laser beam into the aerosol beam to form a plasma; a detection device that detects a wavelength of a light emission caused by the formation of the plasma. The detection device can be a spectrometer having at least one grating and a gated intensified charge-coupled device. The apparatus may also include a processor that correlates the wavelength of the light emission caused by the formation of the plasma with an identity of an element that corresponds to the wavelength. Furthermore, the apparatus can also include an aerosol generator for forming an aerosol beam from bulk materials. A method for detecting elements in an aerosol is also disclosed.

  5. iDirector with Alex Laskin: Atmospheric aerosols | EMSL

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

    Alex Laskin: Atmospheric aerosols iDirector with Alex Laskin: Atmospheric aerosols Released: September 03, 2014 iDirector with Alex Laskin iDirector interview with EMSL scientist...

  6. Application of computational fluid dynamics to aerosol sampling and concentration

    E-Print Network [OSTI]

    Hu, Shishan

    2009-05-15T23:59:59.000Z

    An understanding of gas-liquid two-phase interactions, aerosol particle deposition, and heat transfer is needed. Computational Fluid Dynamics (CFD) is becoming a powerful tool to predict aerosol behavior for related design work. In this study...

  7. Apparatus for rapid measurement of aerosol bulk chemical composition

    DOE Patents [OSTI]

    Lee, Yin-Nan E. (East Setauket, NY); Weber, Rodney J. (Atlanta, GA)

    2003-01-01T23:59:59.000Z

    An apparatus and method for continuous on-line measurement of chemical composition of aerosol particles with a fast time resolution are provided. The apparatus includes a modified particle size magnifier for producing activated aerosol particles and a collection device which collects the activated aerosol particles into a liquid stream for quantitative analysis by analytical methods. The method provided for on-line measurement of chemical composition of aerosol particles includes exposing aerosol carrying sample air to hot saturated steam thereby forming activated aerosol particles; collecting the activated aerosol particles by a collection device for delivery as a jet stream onto an impaction surface; flushing off the activated aerosol particles from the impaction surface into a liquid stream for delivery of the collected liquid stream to an analytical instrument for quantitative measurement.

  8. Apparatus for rapid measurement of aerosol bulk chemical composition

    DOE Patents [OSTI]

    Lee, Yin-Nan E.; Weber, Rodney J.; Orsini, Douglas

    2006-04-18T23:59:59.000Z

    An apparatus for continuous on-line measurement of chemical composition of aerosol particles with a fast time resolution is provided. The apparatus includes an enhanced particle size magnifier for producing activated aerosol particles and an enhanced collection device which collects the activated aerosol particles into a liquid stream for quantitative analysis by analytical means. Methods for on-line measurement of chemical composition of aerosol particles are also provided, the method including exposing aerosol carrying sample air to hot saturated steam thereby forming activated aerosol particles; collecting the activated aerosol particles by a collection device for delivery as a jet stream onto an impaction surface; and flushing off the activated aerosol particles from the impaction surface into a liquid stream for delivery of the collected liquid stream to an analytical instrument for quantitative measurement.

  9. The seasonality of aerosol properties in Big Bend National Park

    E-Print Network [OSTI]

    Allen, Christopher Lee

    2007-04-25T23:59:59.000Z

    ), to characterize the seasonal variability of the Big Bend regions aerosol optical properties. Mass extinction efficiencies and relative humidity scattering enhancement factors were calculated for both externally and internally mixed aerosol populations for all size...

  10. aerosol particle penetration: Topics by E-print Network

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

    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 Lmin to 169.9...

  11. Relating Aerosol Absorption due to Soot, Organic Carbon, and Dust to Emission Sources Determined from In-situ Chemical Measurements

    SciTech Connect (OSTI)

    Cazorla, Alberto; Bahadur, R.; Suski, Kaitlyn; Cahill, John F.; Chand, Duli; Schmid, Beat; Ramanathan, V.; Prather, Kimberly

    2013-09-17T23:59:59.000Z

    Estimating the aerosol contribution to the global or regional radiative forcing can take advantage of the relationship between the spectral aerosol optical properties and the size and chemical composition of aerosol. Long term global optical measurements from observational networks or satellites can be used in such studies, and using in-situ chemical mixing state measurements can help us to constrain the limitations of such an estimation. In this study, the Absorption Ångström Exponent (AAE) and the Scattering Ångström Exponent (SAE) are used to develop a new methodology for deducing chemical speciation based on wavelength dependence of the optical properties. In addition, in-situ optical properties and single particle chemical composition measured during three aircraft field campaigns are combined in order to validate the methodology for the estimation of aerosol composition using spectral optical properties. Results indicate a dominance of mixed types in the classification leading to an underestimation of the primary sources, however secondary sources are better classified. The distinction between carbonaceous aerosols from fossil fuel and biomass burning origins is not clear. On the other hand, the knowledge of the aerosol sources in California from chemical studies help to identify other misclassification such as the dust contribution.

  12. Direct radiative forcing due to aerosols in Asia during Soon-Ung Parka,, Jaein I. Jeongb

    E-Print Network [OSTI]

    Park, Rokjin

    Direct radiative forcing due to aerosols in Asia during March 2002 Soon-Ung Parka,, Jaein I. Jeongb Model (CRM) of Community Climate Model 3 and the output of the fifth generation of meso-scale model (MM5 in the global climate system by changing atmospheric radiation balance (Tegen and Fung, 1994; Andreae, 1996; Li

  13. Progress Report for Proposal entitled " The Direct Radiative Forcing of Biomass Burning Aerosols: Investigations during

    E-Print Network [OSTI]

    Progress Report for Proposal entitled " The Direct Radiative Forcing of Biomass Burning Aerosols irradiances (DSWI) at the surface and the atmospheric heating/cooling rate profiles. For example, the DSWI the Clouds and the Earth's Radiant Energy System (CERES) instrument from the Tropical Rainfall Measuring

  14. AEROSOL-CLOUD INTERACTIONS CONTROL OF EARTH RADIATION AND LATENT HEAT RELEASE BUDGETS

    E-Print Network [OSTI]

    Daniel, Rosenfeld

    role in energizing the climate system: they reflect much of the solar radiation back to space and so and aerosols reflect back to space 22.5% of the solar radiation (Figure 1). An additional 8.8% is reflected.1% are absorbed by the surface. Surface evaporation consumes 22.8% of the solar energy that subsequently heats

  15. Sealing Ducts in Large Commercial Buildings with Aerosolized Sealant M. P. Modera, O. Brzozowski**

    E-Print Network [OSTI]

    LBNL-42414 1 Sealing Ducts in Large Commercial Buildings with Aerosolized Sealant Particles M. P buildings is on the order of 10 kWh/m2 per year (1 kWh/ft2 ). We have tested, in two large commercial technology is capable of sealing the leaks in a large commercial building duct system within a reasonable

  16. Influence of anthropogenic aerosol on cloud optical depth and albedo shown by satellite measurements

    E-Print Network [OSTI]

    - flux of sulfate aerosol from industrial regions of Europe or North America to remote areas of the North- atmosphere system over the industrial period and a cooling influence on climate. Estimates of the global), the negative sign indicating a cooling influence. Such a global mean forcing would more than offset the warming

  17. Aerosol Science 32 (2001) 14791504 www.elsevier.com/locate/jaerosci

    E-Print Network [OSTI]

    Zachariah, Michael R.

    controlled internal phase segregation during aerosol coagulation H. Struchtrup 1 , M. Luskin, M. R. Zachariah a monodisperse particle size distribution. The dynamical behavior of such a system is presented. c 2001 Elsevier and space of the particle size distribution function, which can include all the driving forces

  18. A Model for Kinetically Controlled Internal Phase Segregation During Aerosol Coagulation

    E-Print Network [OSTI]

    A Model for Kinetically Controlled Internal Phase Segregation During Aerosol Coagulation H size distribution. The dynamical behavior of such a system is presented. 1 Introduction The evolution). The GDE has been employed to characterize the behavior in time and space of the particle size distribution

  19. Rare sulfur and triple oxygen isotope geochemistry of volcanogenic sulfate aerosols

    E-Print Network [OSTI]

    Bindeman, Ilya N.

    Rare sulfur and triple oxygen isotope geochemistry of volcanogenic sulfate aerosols I.N. Bindeman a of Technology, Pasadena, CA, USA c Department of Earth and Planetary Sciences, McGill University, Montreal, Que., Canada d Department of Geology and Earth System Science Interdisciplinary Center, University of Maryland

  20. A case for variational geomagnetic data assimilation: insights from a one-dimensional, nonlinear, and sparsely observed MHD system

    E-Print Network [OSTI]

    Fournier, Alexandre; Alboussière, Thierry

    2007-01-01T23:59:59.000Z

    Secular variations of the geomagnetic field have been measured with a continuously improving accuracy during the last few hundred years, culminating nowadays with satellite data. It is however well known that the dynamics of the magnetic field is linked to that of the velocity field in the core and any attempt to model secular variations will involve a coupled dynamical system for magnetic field and core velocity. Unfortunately, there is no direct observation of the velocity. Independently of the exact nature of the above-mentioned coupled system -- some version being currently under construction -- the question is debated in this paper whether good knowledge of the magnetic field can be translated into good knowledge of core dynamics. Furthermore, what will be the impact of the most recent and precise geomagnetic data on our knowledge of the geomagnetic field of the past and future? These questions are cast into the language of variational data assimilation, while the dynamical system considered in this pape...