Sample records for aerosol optical thickness

  1. 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

  2. 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

  3. 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

  4. 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,...

  5. Maritime aerosol optical thickness measured by handheld sun photometers Kirk D. Knobelspiessea,b

    E-Print Network [OSTI]

    thickness (AOT) and 2ngstrfm exponent reveal varied aerosol populations. A K-means unsupervised Sensor Inter-comparison and Merger for Biological and Interdisciplinary Oceanic Studies (SIMBIOS) Project

  6. 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

  7. Separating real and apparent effects of cloud, humidity, and dynamics on aerosol optical thickness near cloud edges

    E-Print Network [OSTI]

    Li, Zhanqing

    have reported correlations between AOT and cloud cover, pointing to potential cloud contamination of Energy's Atmospheric Radiation Measurement Program. It was found that aerosol humidification effects can explain about one fourth of the correlation between the cloud cover and AOT. New particle genesis

  8. 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

  9. 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. __________________________________________________

  10. 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

  11. Effect of Aerosol Humidification on the Column Aerosol Optical Thickness

    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 AdministrationField Campaign:INEA :Work4/11ComputationalEdNERSC: DeliveringEdwinover the ARM

  12. 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.

  13. 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

  14. 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.

  15. aerosol optical depths: Topics by E-print Network

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

    AERONET, AVHRR and 3 MODIS 4 A. Hauser, D. Oesch have been used to 9 retrieve the spatial distribution of aerosol optical depth for 10 central Europe. At eight AERONET sites,...

  16. aerosol optical depth: Topics by E-print Network

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

    AERONET, AVHRR and 3 MODIS 4 A. Hauser, D. Oesch have been used to 9 retrieve the spatial distribution of aerosol optical depth for 10 central Europe. At eight AERONET sites,...

  17. THE TURBULENCE POWER SPECTRUM IN OPTICALLY THICK INTERSTELLAR CLOUDS

    SciTech Connect (OSTI)

    Burkhart, Blakesley; Lazarian, A. [Astronomy Department, University of Wisconsin, Madison, 475 North Charter Street, WI 53711 (United States); Ossenkopf, V.; Stutzki, J. [Physikalisches Institut der Universitaet zu Koeln, Zuelpicher Strasse 77, D-50937 Koeln (Germany)

    2013-07-10T23:59:59.000Z

    The Fourier power spectrum is one of the most widely used statistical tools to analyze the nature of magnetohydrodynamic (MHD) turbulence in the interstellar medium. Lazarian and Pogosyan predicted that the spectral slope should saturate to -3 for an optically thick medium and many observations exist in support of their prediction. However, there have not been any numerical studies to date for testing these results. We analyze the spatial power spectrum of MHD simulations with a wide range of sonic and Alfvenic Mach numbers, which include radiative transfer effects of the {sup 13}CO transition. We numerically confirm the predictions of Lazarian and Pogosyan that the spectral slope of line intensity maps of an optically thick medium saturates to -3. Furthermore, for very optically thin supersonic CO gas, where the density or CO abundance values are too low to excite emission in all but the densest shock compressed gas, we find that the spectral slope is shallower than expected from the column density. Finally, we find that mixed optically thin/thick CO gas, which has average optical depths on the order of unity, shows mixed behavior: for super-Alfvenic turbulence, the integrated intensity power spectral slopes generally follow the same trend with sonic Mach number as the true column density power spectrum slopes. However, for sub-Alfvenic turbulence the spectral slopes are steeper with values near -3 which are similar to the very optically thick regime.

  18. Characterizing Aerosol Distributions and Optical Properties Using the NASA Langley High Spectral Resolution Lidar

    SciTech Connect (OSTI)

    Hostetler, Chris; Ferrare, Richard

    2013-02-14T23:59:59.000Z

    The objective of this project was to provide vertically and horizontally resolved data on aerosol optical properties to assess and ultimately improve how models represent these aerosol properties and their impacts on atmospheric radiation. The approach was to deploy the NASA Langley Airborne High Spectral Resolution Lidar (HSRL) and other synergistic remote sensors on DOE Atmospheric Science Research (ASR) sponsored airborne field campaigns and synergistic field campaigns sponsored by other agencies to remotely measure aerosol backscattering, extinction, and optical thickness profiles. Synergistic sensors included a nadir-viewing digital camera for context imagery, and, later in the project, the NASA Goddard Institute for Space Studies (GISS) Research Scanning Polarimeter (RSP). The information from the remote sensing instruments was used to map the horizontal and vertical distribution of aerosol properties and type. The retrieved lidar parameters include profiles of aerosol extinction, backscatter, depolarization, and optical depth. Products produced in subsequent analyses included aerosol mixed layer height, aerosol type, and the partition of aerosol optical depth by type. The lidar products provided vertical context for in situ and remote sensing measurements from other airborne and ground-based platforms employed in the field campaigns and was used to assess the predictions of transport models. Also, the measurements provide a data base for future evaluation of techniques to combine active (lidar) and passive (polarimeter) measurements in advanced retrieval schemes to remotely characterize aerosol microphysical properties. The project was initiated as a 3-year project starting 1 January 2005. It was later awarded continuation funding for another 3 years (i.e., through 31 December 2010) followed by a 1-year no-cost extension (through 31 December 2011). This project supported logistical and flight costs of the NASA sensors on a dedicated aircraft, the subsequent analysis and archival of the data, and the presentation of results in conferences, workshops, and publications. DOE ASR field campaigns supported under this project included - MAX-Mex /MILAGRO (2006) - TexAQS 2006/GoMACCS (2006) - CHAPS (2007) - RACORO (2009) - CARE/CalNex (2010) In addition, data acquired on HSRL airborne field campaigns sponsored by other agencies were used extensively to fulfill the science objectives of this project and the data acquired have been made available to other DOE ASR investigators upon request.

  19. Lidar Measurements of the Vertical Distribution of Aerosol Optical and Physical Properties over Central Asia

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

    Chen, Boris B.; Sverdlik, Leonid G.; Imashev, Sanjar A.; Solomon, Paul A.; Lantz, Jeffrey; Schauer, James J.; Shafer, Martin M.; Artamonova, Maria S.; Carmichael, Gregory R.

    2013-01-01T23:59:59.000Z

    The vertical structure of aerosol optical and physical properties was measured by Lidar in Eastern Kyrgyzstan, Central Asia, from June 2008 to May 2009. Lidar measurements were supplemented with surface-based measurements of PM2.5and PM10mass and chemical composition in both size fractions. Dust transported into the region is common, being detected 33% of the time. The maximum frequency occurred in the spring of 2009. Dust transported to Central Asia comes from regional sources, for example, Taklimakan desert and Aral Sea basin, and from long-range transport, for example, deserts of Arabia, Northeast Africa, Iran, and Pakistan. Regional sources are characterized by pollutionmore »transport with maximum values of coarse particles within the planetary boundary layer, aerosol optical thickness, extinction coefficient, integral coefficient of aerosol backscatter, and minimum values of the Ångström exponent. Pollution associated with air masses transported over long distances has different characteristics during autumn, winter, and spring. During winter, dust emissions were low resulting in high values of the Ångström exponent (about 0.51) and the fine particle mass fraction (64%). Dust storms were more frequent during spring with an increase in coarse dust particles in comparison to winter. The aerosol vertical profiles can be used to lower uncertainty in estimating radiative forcing.« less

  20. Correction to “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.

    2014-02-16T23:59:59.000Z

    In the paper “Hyperspectral aerosol optical depths from TCAP flights” by Y. Shinozuka et al. (Journal of Geophysical Research: Atmospheres, 118, doi:10.1002/2013JD020596, 2013), Tables 1 and 2 were published with the column heads out of order. Tables 1 and 2 are published correctly here. The publisher regrets the error.

  1. 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.

  2. Geometrical Optics of Dense Aerosols: Forming Dense Plasma Slabs Michael J. Hay,1,* Ernest J. Valeo,2

    E-Print Network [OSTI]

    Geometrical Optics of Dense Aerosols: Forming Dense Plasma Slabs Michael J. Hay,1,* Ernest J. Valeo aerosol to assume this geometry. However, whereas the geometrical optics of dilute aerosols is a well-developed field, the dense aerosol limit is mostly unexplored. Yet controlling the geometrical optics of dense

  3. Satellite characterization of urban aerosols: Importance of including hygroscopicity and mixing state in the retrieval algorithms

    E-Print Network [OSTI]

    Satellite characterization of urban aerosols: Importance of including hygroscopicity and mixing the sensitivity of the calculated optical properties of urban aerosols to (1) hygroscopicity and (2) internal of satellite retrievals of aerosol optical thickness (t) and aerosol effective radius (reff). State

  4. Optical Properties of Mixed Black Carbon, Inorganic and Secondary Organic Aerosols

    SciTech Connect (OSTI)

    Paulson, S E

    2012-05-30T23:59:59.000Z

    Summarizes the achievements of the project, which are divided into four areas: 1) Optical properties of secondary organic aerosols; 2) Development and of a polar nephelometer to measure aerosol optical properties and theoretical approaches to several optical analysis problems, 3) Studies on the accuracy of measurements of absorbing carbon by several methods, and 4) Environmental impacts of biodiesel.

  5. Africa Aerosol Optical Depth Obtained From MISR

    E-Print Network [OSTI]

    Frank, Thomas D.

    OpticalDepth Central African Republic Chad Djibouti Egypt Ethiopia Libya Kenya Somalia Sudan Uganda #12;Southern Africa Ethiopia Libya Kenya Somalia Sudan Uganda #12;Southern Africa 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 Mean Seasonal

  6. Parametric Resonance of Optically Trapped Aerosols

    E-Print Network [OSTI]

    R. Di Leonardo; G. Ruocco; J. Leach; M. J. Padgett; A. J. Wright; J. M. Girkin; D. R. Burnham; D. McGloin

    2007-02-23T23:59:59.000Z

    The Brownian dynamics of an optically trapped water droplet are investigated across the transition from over to under-damped oscillations. The spectrum of position fluctuations evolves from a Lorentzian shape typical of over-damped systems (beads in liquid solvents), to a damped harmonic oscillator spectrum showing a resonance peak. In this later under-damped regime, we excite parametric resonance by periodically modulating the trapping power at twice the resonant frequency. The power spectra of position fluctuations are in excellent agreement with the obtained analytical solutions of a parametrically modulated Langevin equation.

  7. Radiative Effects of Dust Aerosols, Natural Cirrus Clouds and Contrails: Broadband Optical Properties and Sensitivity Studies

    E-Print Network [OSTI]

    Yi, Bingqi

    2013-07-09T23:59:59.000Z

    This dissertation aims to study the broadband optical properties and radiative effects of dust aerosols and ice clouds. It covers three main topics: the uncertainty of dust optical properties and radiative effects from the dust particle shape...

  8. Radiative Effects of Dust Aerosols, Natural Cirrus Clouds and Contrails: Broadband Optical Properties and Sensitivity Studies 

    E-Print Network [OSTI]

    Yi, Bingqi

    2013-07-09T23:59:59.000Z

    This dissertation aims to study the broadband optical properties and radiative effects of dust aerosols and ice clouds. It covers three main topics: the uncertainty of dust optical properties and radiative effects from the dust particle shape...

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

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

    Newsom, Rob; Goldsmith, John

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

  10. Optical Histology: A Method to Visualize Microvasculature in Thick Tissue Sections of Mouse Brain

    E-Print Network [OSTI]

    Rose, Michael R.

    Optical Histology: A Method to Visualize Microvasculature in Thick Tissue Sections of Mouse Brain% paraformaldehyde. The organ is then sliced into 1 mm sections and optically cleared, or made transparent, using FocusClear, a proprietary optical clearing agent. After optical clearing, the DiI-labeled tissue

  11. Determination of refractive index, thickness, and the optical losses of thin films from

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Determination of refractive index, thickness, and the optical losses of thin films from prism­film.4760, 300.1030. 1. Introduction Transparent thin films find wide applications in optics: coating, sensors and optical losses. The optical losses of a thin film have three different origins: sur- face scattering due

  12. Near-Field Scanning Optical Microscopy of Temperature-and Thickness-Dependent Morphology and

    E-Print Network [OSTI]

    Buratto, Steve

    Near-Field Scanning Optical Microscopy of Temperature- and Thickness-Dependent Morphology 21, 2000 We use near-field scanning optical microscopy (NSOM) to probe the local optical spectroscopy with bulk techniques such as differ- ential scanning calorimetry (DSC) and X-ray diffractom- etry

  13. Aerosol optical hygroscopicity measurements during the 2010 CARES Campaign

    SciTech Connect (OSTI)

    Atkinson, D. B.; Radney, J. G.; Lum, J.; Kolesar, K. R.; Cziczo, Daniel J.; Pekour, Mikhail S.; Zhang, Qi; Setyan, Ari; Zelenyuk, Alla; Cappa, Christopher

    2015-01-01T23:59:59.000Z

    Measurements of the effect of water uptake on particulate light extinction or scattering made at two locations during the 2010 CARES study around Sacramento, CA are reported. The observed influence of water uptake, characterized through the dimensionless optical hygroscopicity parameter ?, is compared with calculations constrained by observed particle size distributions and size-dependent particle composition. A closure assessment has been carried out that allowed for determination of the average hygroscopic growth factors (GF) at 85% relative humidity and the dimensionless hygroscopicity parameter ? for oxygenated organic aerosol (OA) and for supermicron particles, yielding ? = 0.1–0.15 and 0.9–1.0, respectively. The derived range of oxygenated OA ? values are in line with previous observations. The relatively large values for supermicron particles is consistent with substantial contributions of sea salt-containing particles in this size range. Analysis of time-dependent variations in the supermicron particle hygroscopicity suggest that atmospheric processing, specifically chloride displacement by nitrate and the accumulation of secondary organics on supermicron particles, can lead to substantial depression of the observed GF.

  14. FLUORESCENCE AND FIBER-OPTICS BASED REAL-TIME THICKNESS SENSOR FOR DYNAMIC LIQUID FILMS

    E-Print Network [OSTI]

    Narain, Amitabh

    /analyzed the incident reflected waves to identify and measure the total transit time of the sound wave (of known wave-speed1 FLUORESCENCE AND FIBER-OPTICS BASED REAL-TIME THICKNESS SENSOR FOR DYNAMIC LIQUID FILMS T. W. Ng/disadvantages of many known liquid film thickness sensing devices (viz. conductivity probes, reflectance based fiber

  15. Aerosol radiative forcing and the accuracy of satellite aerosol optical depth retrieval

    E-Print Network [OSTI]

    ) of the AVHRR (Advanced Very High Resolution Radiometer) is typically between 0.06 and 0.15, while the RMSE between t = 0.1 and t = 0.8. The Department of Energy research satellite instrument, the Multispectral aerosol radiative forcing are known, the predictions of future global warming may remain unacceptably high

  16. Thickness-dependent changes in the optical properties of PPV-and PF-based polymer light emitting diodes

    E-Print Network [OSTI]

    Carter, Sue

    the thickness-dependent optical properties of single layer polymer light emitting diodes for two materials, poly the electronic and optical properties of these materials in light emitting diode LED structures.2 OurThickness-dependent changes in the optical properties of PPV- and PF-based polymer light emitting

  17. Measurements of aerosol vertical profiles and optical properties during INDOEX

    E-Print Network [OSTI]

    Markowicz,5 James R. Campbell,6 James D. Spinhirne,7 Howard R. Gordon,2 and James E. Johnson3 Received 5 field phase. Measurements were made from two platforms: the NOAA ship R/V Ronald H. Brown. Markowicz, J. R. Campbell, J. D. Spinhirne, H. R. Gordon, and J. E. Johnson, Measurements of aerosol

  18. Synthesis of information on aerosol optical properties Hongqing Liu,1

    E-Print Network [OSTI]

    Chin, Mian

    revealed a significant decrease in sur- face solar heating due to the presence of absorbing aerosols, which spectral dependence derived from AERONET retrievals. The asymmetry parameter over the solar spectrum radiation balance [Intergovernmental Panel on Climate Change, 2001]. Their potential to increase reflected

  19. Smoke over haze: Comparative analysis of satellite, surface radiometer, and airborne in situ measurements of aerosol optical

    E-Print Network [OSTI]

    Li, Zhanqing

    measurements of aerosol optical properties and radiative forcing over the eastern United States Brian Vant their consistency for application to satellite retrievals of optical depth and radiative forcing. These optical properties were combined with MODIS reflectance observations to calculate optical depth. The use of AERONET

  20. 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

  1. Asymptotic solution of light transport problems in optically thick luminescent media

    SciTech Connect (OSTI)

    ?ahin-Biryol, Derya, E-mail: dsahin@ucmerced.edu; Ilan, Boaz [Applied Mathematics Unit, School of Natural Sciences, University of California Merced, 5200 North Lake Road, Merced, California 95343 (United States)

    2014-06-15T23:59:59.000Z

    We study light transport in optically thick luminescent random media. Using radiative transport theory for luminescent media and applying asymptotic and computational methods, a corrected diffusion approximation is derived with the associated boundary conditions and boundary layer solution. The accuracy of this approach is verified for a plane-parallel slab problem. In particular, the reduced system models accurately the effect of reabsorption. The impacts of varying the Stokes shift and using experimentally measured luminescence data are explored in detail. The results of this study have application to the design of luminescent solar concentrators, fluorescence medical imaging, and optical cooling using anti-Stokes fluorescence.

  2. Temperature inversion on the surface of externally heated optically thick multigrain dust clouds

    E-Print Network [OSTI]

    Dejan Vinkovic

    2006-12-01T23:59:59.000Z

    It was recently discovered that the temperature in the surface layer of externally heated optically thick gray dust clouds increases with the optical depth for some distance from the surface, as opposed to the normal decrease in temperature with distance in the rest of the cloud. This temperature inversion is a result of efficient absorption of diffuse flux from the cloud interior by the surface dust exposed to the external radiation. A micron or bigger size grains experience this effect when the external flux is of stellar spectrum. We explore what happens to the effect when dust is a mixture of grain sizes (multigrain). Two possible boundary conditions are considered: i) a constant external flux without constrains on the dust temperature, and ii) the maximum dust temperature set to the sublimation temperature. We find that the first condition allows small grains to completely suppress the temperature inversion of big grains if the overall opacity is dominated by small grains. The second condition enables big grains to maintain the inversion even when they are a minor contributor to the opacity. In reality, the choice of boundary condition depends on the dust dynamics. When applied to the physics of protoplanetary disks, the temperature inversion leads to a previously unrecognized disk structure where optically thin dust can exist inside the dust destruction radius of an optically thick disk. We conclude that the transition between the dusty disk and the gaseous inner clearing is not a sharp edge, but rather a large optically thin region.

  3. 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.

  4. Climatology of aerosol optical depth in north?central Oklahoma: 1992–2008

    SciTech Connect (OSTI)

    Michalsky, Joseph J.; Denn, Frederick; Flynn, Connor J.; Hodges, G. B.; Kiedron, Piotr; Koontz, Annette S.; Schlemmer, James; Schwartz, Stephen E.

    2010-04-13T23:59:59.000Z

    Aerosol optical depth (AOD) has been measured at the Atmospheric Radiation Measurement Program central facility near Lamont, Oklahoma, since the fall of 1992. Most of the data presented are from the multifilter rotating shadowband radiometer, a narrow?band, interference?filter Sun radiometer with five aerosol bands in the visible and near infrared; however, AOD measurements have been made simultaneously and routinely at the site by as many as three different types of instruments, including two pointing Sun radiometers. Scatterplots indicate high correlations and small biases consistent with earlier comparisons. The early part of this 16 year record had a disturbed stratosphere with residual Mt. Pinatubo aerosols, followed by the cleanest stratosphere in decades. As such, the last 13 years of the record reflect changes that have occurred predominantly in the troposphere. The field calibration technique is briefly described and compared to Langley calibrations from Mauna Loa Observatory. A modified cloudscreening technique is introduced that increases the number of daily averaged AODs retrieved annually to about 250 days compared with 175 days when a more conservative method was employed in earlier studies. AODs are calculated when the air mass is less than six; that is, when the Sun’s elevation is greater than 9.25°. The more inclusive cloud screen and the use of most of the daylight hours yield a data set that can be used to more faithfully represent the true aerosol climate for this site. The diurnal aerosol cycle is examined month?by?month to assess the effects of an aerosol climatology on the basis of infrequent sampling such as that from satellites.

  5. Hybrid glass coatings for optical fibers: effect of coating thickness on strength and dynamic fatigue characteristics of silica fibers

    E-Print Network [OSTI]

    Matthewson, M. John

    Hybrid glass coatings for optical fibers: effect of coating thickness on strength and dynamic, the State University of New Jersey, Piscataway, NJ 08854, USA c Laboratory of Optical Fiber Technology, UMCS, Lublin, 20031, Poland, ABSTRACT Specialty optical fibers operating in harsh aerospace environments

  6. Evaluation of the carbon content of aerosols from the burn- ing of biomass in the Brazilian Amazon using thermal, op- tical and thermal-optical analysis methods

    SciTech Connect (OSTI)

    Soto-Garcia, Lydia L.; Andreae, Meinrat O.; Andreae, Tracey W.; taxo, Paulo Ar-; Maenhaut, Willy; Kirchstetter, Thomas; Novakov, T.; Chow, Judith C.; Mayol-Bracero, Olga L.

    2011-06-03T23:59:59.000Z

    Aerosol samples were collected at a pasture site in the Amazon Basin as part of the project LBA-SMOCC-2002 (Large-Scale Biosphere-Atmosphere Experiment in Amazonia - Smoke Aerosols, Clouds, Rainfall and Climate: Aerosols from Biomass Burning Perturb Global and Regional Climate). Sampling was conducted during the late dry season, when the aerosol composition was dominated by biomass burning emissions, especially in the submicron fraction. A 13-stage Dekati low-pressure impactor (DLPI) was used to collect particles with nominal aerodynamic diameters (D{sub p}) ranging from 0.03 to 0.10 m. Gravimetric analyses of the DLPI substrates and filters were performed to obtain aerosol mass concentrations. The concentrations of total, apparent elemental, and organic carbon (TC, EC{sub a}, and OC) were determined using thermal and thermal-optical analysis (TOA) methods. A light transmission method (LTM) was used to determine the concentration of equivalent black carbon (BC{sub e}) or the absorbing fraction at 880 nm for the size-resolved samples. During the dry period, due to the pervasive presence of fires in the region upwind of the sampling site, concentrations of fine aerosols (D{sub p} < 2.5 {mu}m: average 59.8 {mu}g m{sup -3}) were higher than coarse aerosols (D{sub p} > 2.5 {mu}m: 4.1 {mu}g m{sup -3}). Carbonaceous matter, estimated as the sum of the particulate organic matter (i.e., OC x 1.8) plus BC{sub e}, comprised more than 90% to the total aerosol mass. Concentrations of EC{sub a} (estimated by thermal analysis with a correction for charring) and BCe (estimated by LTM) averaged 5.2 {+-} 1.3 and 3.1 {+-} 0.8 {mu}g m{sup -3}, respectively. The determination of EC was improved by extracting water-soluble organic material from the samples, which reduced the average light absorption {angstrom} exponent of particles in the size range of 0.1 to 1.0 {mu}m from > 2.0 to approximately 1.2. The size-resolved BC{sub e} measured by the LTM showed a clear maximum between 0.4 and 0.6 m in diameter. The concentrations of OC and BC{sub e} varied diurnally during the dry period, and this variation is related to diurnal changes in boundary layer thickness and in fire frequency.

  7. Cooperative emission of a pulse train in an optically thick scattering medium

    E-Print Network [OSTI]

    Kwong, C C; Delande, D; Pierrat, R; Wilkowski, D

    2015-01-01T23:59:59.000Z

    An optically thick cold atomic cloud emits a coherent flash of light in the forward direction when the phase of an incident probe field is abruptly changed. Due to cooperativity, the duration of this phenomena can be much shorter than the excited lifetime of a single atom and, surprisingly, it weakly depends on the temperature of the gas and on the probe frequency. Repeating periodically the abrupt change of the incident field phase, we generate a forward transmitted train of pulses with short repetition time. It is even possible to quench single atom fluorescence, transferring almost completely the incident power into the pulse train with a high intensity contrast.

  8. Atmospheric effects of nuclar war aerosols in general circulation model simulations: Influence of smoke optical properties

    SciTech Connect (OSTI)

    Thompson, S.L.; Ramaswamy, V.; Covey, C.

    1987-09-20T23:59:59.000Z

    A global atmospheric general circulation model (GCM) is modified to include radiative transfer parameterizations for the absorption and scattering of solar radiation and the absorption of thermal infrared (IR) radiation by smoke aerosols. The solar scattering modifications include a parameterization for diagnosing smoke optical properties as a function of the time- and space-dependent smoke particle radii. The aerosol IR modifications allow for both the ''grey'' absorber approximation and a broadband approximation that resolves the aerosol absorption in four spectral intervals. We examine the sensitivity of some GCM-simulated atmospheric and climatic effects to the optical properties and radiative transfer parameterizations used in studies of massive injections of smoke. Specifically, we test the model response to solar scattering versus nonscattering smoke, variations in prescribed smoke single scattering albedo and IR specific absorption, and interactive versus fixed smoke optical properties. Hypothetical nuclear war created smoke scenarios assume the July injection of 60 or 180 Tg of smoke over portions of the mid-latitude land areas of the northern hemisphere. Atmospheric transport and scavenging of the smoke are included. Nonscattering smoke cases produce roughly 40 Wm/sup -2/ more Earth-atmosphere solar irradiance absorption over the northern hemisphere, when compared to scattering smoke cases having equivalent specific absorption efficiencies. Varying the elemental carbon content of smoke over a plausible range produces a 4/sup 0/--6 /sup 0/C change in average mid-latitude land surface temperature, and a variation of about 0.1 in zonally averaged planetary albedo in the northern hemisphere.

  9. Satellite based retrieval of aerosol optical thickness: The effect of sun and satellite geometry

    E-Print Network [OSTI]

    be retrieved using the ATSR-2 with an accuracy of 0.03. The advanced very high resolution radiometer (AVHRR in the earth's energy balance by scattering and absorbing solar and terrestrial radiation [Chylek and Coakley warming effects of green house gases [Hansen, 2002]. Due to a high spatial and temporal variability

  10. TOWARDS CIGS SOLAR CELLS WITH REDUCED FILM THICKNESS: A STUDY OF OPTICAL PROPERTIES AND OF PHOTONIC STRUCTURES FOR LIGHT TRAPPING

    E-Print Network [OSTI]

    TOWARDS CIGS SOLAR CELLS WITH REDUCED FILM THICKNESS: A STUDY OF OPTICAL PROPERTIES AND OF PHOTONIC ABSTRACT: In view of large-scale exploitation of CuIn1-xGaxSe2 (CIGS) solar cells for photovoltaic energy. In this work we perform a full study of optical properties of CIGS solar cells grown by a hybrid sputtering

  11. Fluorescence measurements for evaluating the application of multivariate analysis techniques to optically thick environments.

    SciTech Connect (OSTI)

    Reichardt, Thomas A.; Timlin, Jerilyn Ann; Jones, Howland D. T.; Sickafoose, Shane M.; Schmitt, Randal L.

    2010-09-01T23:59:59.000Z

    Laser-induced fluorescence measurements of cuvette-contained laser dye mixtures are made for evaluation of multivariate analysis techniques to optically thick environments. Nine mixtures of Coumarin 500 and Rhodamine 610 are analyzed, as well as the pure dyes. For each sample, the cuvette is positioned on a two-axis translation stage to allow the interrogation at different spatial locations, allowing the examination of both primary (absorption of the laser light) and secondary (absorption of the fluorescence) inner filter effects. In addition to these expected inner filter effects, we find evidence that a portion of the absorbed fluorescence is re-emitted. A total of 688 spectra are acquired for the evaluation of multivariate analysis approaches to account for nonlinear effects.

  12. Optical instrument for measurement of vaginal coating thickness by drug delivery formulations

    SciTech Connect (OSTI)

    Henderson, Marcus H.; Peters, Jennifer J.; Walmer, David K.; Couchman, Grace M.; Katz, David F. [Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708 (United States); Department of Obstetrics and Gynecology, Duke University, Durham, North Carolina 27710 (United States); Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708 and Department of Obstetrics and Gynecology, Duke University, Durham, North Carolina 27710 (United States)

    2005-03-01T23:59:59.000Z

    An optical device has been developed for imaging the human vaginal epithelial surfaces, and quantitatively measuring distributions of coating thickness of drug delivery formulations - such as gels - applied for prophylaxis, contraception or therapy. The device consists of a rigid endoscope contained within a 27-mm-diam hollow, polished-transparent polycarbonate tube (150 mm long) with a hemispherical cap. Illumination is from a xenon arc. The device is inserted into, and remains stationary within the vagina. A custom gearing mechanism moves the endoscope relative to the tube, so that it views epithelial surfaces immediately apposing its outer surface (i.e., 150 mm long by 360 deg. azimuthal angle). Thus, with the tube fixed relative to the vagina, the endoscope sites local regions at distinct and measurable locations that span the vaginal epithelium. The returning light path is split between a video camera and photomultiplier. Excitation and emission filters in the light path enable measurement of fluorescence of the sited region. Thus, the instrument captures video images simultaneously with photometric measurement of fluorescence of each video field [{approx}10 mm diameter; formulations are labeled with 0.1% w/w United States Pharmacoepia (USP) injectable sodium fluorescein]. Position, time and fluorescence measurements are continuously displayed (on video) and recorded (to a computer database). The photomultiplier output is digitized to quantify fluorescence of the endoscope field of view. Quantification of the thickness of formulation coating of a surface sited by the device is achieved due to the linear relationship between thickness and fluorescence intensity for biologically relevant thin layers (of the order of 0.5 mm). Summary measures of coating have been developed, focusing upon extent, location and uniformity. The device has begun to be applied in human studies of model formulations for prophylaxis against infection with HIV and other sexually transmitted pathogens.

  13. Collisionless Shocks and TeV Neutrinos before Supernova Shock Breakout from an Optically Thick Wind

    E-Print Network [OSTI]

    Giacinti, G

    2015-01-01T23:59:59.000Z

    During a supernova explosion, a radiation-dominated shock (RDS) travels through its progenitor. A collisionless shock (CS) is usually assumed to replace it during shock breakout (SB). We demonstrate here that for some realistic progenitors enshrouded in optically thick winds, such as possibly SN 2008D, a CS forms deep inside the wind, soon after the RDS leaves the core, and therefore significantly before SB. The RDS does not survive the transition from the core to the thick wind when the wind close to the core is not sufficiently dense to compensate for the $r^{-2}$ dilution of photons due to shock curvature. This typically happens when the shock velocity is $\\lesssim 0.1 {\\rm c} \\, (\\frac{u_{\\rm w}}{10\\,{\\rm km/s}}) (\\frac{\\dot{M}}{5 \\cdot 10^{-4} \\, {\\rm M}_\\odot {\\rm /yr}})^{-1} (\\frac{r_\\ast}{10^{13}\\,{\\rm cm}})$, where $u_{\\rm w}$, $\\dot{M}$ and $r_\\ast$ are respectively the wind velocity, mass-loss rate and radius of the progenitor star. The radiative CS results in a hard spectrum of the photon flash at...

  14. Codes for optically thick and hot photoionized media - Radiative transfer and new developments

    E-Print Network [OSTI]

    Anne-Marie Dumont; Suzy Collin

    2001-03-20T23:59:59.000Z

    We describe a code designed for hot media {(T $\\ge$} a few 10$^4$ K), optically thick to Compton scattering. It computes the structure of a plane-parallel slab of gas in thermal and ionization equilibrium, illuminated on one side or on both sides by a given spectrum. This code has been presented in a previous paper (Dumont, Abrassart & Collin 2000), where several aspects were already discussed. So we focus here mainly on the recent developments. Presently the code solves the transfer of the continuum with the Accelerated Lambda Iteration method (ALI) and that of the lines in a two stream Eddington approximation, without using the local escape probability formalism to approximate the line transfer. This transfer code is coupled with a Monte Carlo code which allows to take into account direct and inverse Compton diffusions, and to compute the spectrum emitted up to MeV energies, in any geometry. The influence of a few physical parameters is shown, and the importance of the density and pressure distribution (constant density, pressure equilibrium, or hydrostatic equilibrium) is stressed. Recent improvements in the treatment of the atomic data are described, and foreseen developments are mentioned.

  15. 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

  16. Wide-angle imaging LIDAR (WAIL): a ground-based instrument for monitoring the thickness and density of optically thick clouds.

    SciTech Connect (OSTI)

    Love, Steven P.; Davis, A. B. (Anthony B.); Rohde, C. A. (Charles A.); Ho, Cheng,

    2001-01-01T23:59:59.000Z

    Traditional lidar provides little information on dense clouds beyond the range to their base (ceilometry), due to their extreme opacity. At most optical wavelengths, however, laser photons are not absorbed but merely scattered out of the beam, and thus eventually escape the cloud via multiple scattering, producing distinctive extended space- and time-dependent patterns which are, in essence, the cloud's radiative Green functions. These Green functions, essentially 'movies' of the time evolution of the spatial distribution of escaping light, are the primary data products of a new type of lidar: Wide Angle Imaging Lidar (WAIL). WAIL data can be used to infer both optical depth and physical thickness of clouds, and hence the cloud liquid water content. The instrumental challenge is to accommodate a radiance field varying over many orders of magnitude and changing over widely varying time-scales. Our implementation uses a high-speed microchannel plate/crossed delay line imaging detector system with a 60-degree full-angle field of view, and a 532 nm doubled Nd:YAG laser. Nighttime field experiments testing various solutions to this problem show excellent agreement with diffusion theory, and retrievals yield plausible values for the optical and geometrical parameters of the observed cloud decks.

  17. Assessment of MODIS cloud effective radius and optical thickness2 retrievals over the Southeast Pacific with VOCALS-Rex in-situ3

    E-Print Network [OSTI]

    Miami, University of

    in the Earth's radiation budget and the global climate.51 Cloud optical thickness (! ) and effective radius1 Assessment of MODIS cloud effective radius and optical thickness2 retrievals over, the standard 2.1 micron-derived MODIS32 effective radius (re) systematically exceeded the in-situ cloud

  18. 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...

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

    E-Print Network [OSTI]

    Lee, Yong Seob

    2006-08-16T23:59:59.000Z

    collected data during the Asian Aerosol Characterization Experiment (ACE-Asia) to examine the composition and homogeneity of a complex aerosol generated in the deserts and urban regions of China and other Asian countries. An aircraft-based TDMA was used...

  20. Active probing of cloud multiple scattering, optical depth, vertical thickness, and liquid water content using wide-angle imaging LIDAR.

    SciTech Connect (OSTI)

    Love, Steven P.; Davis, A. B. (Anthony B.); Rohde, C. A. (Charles A.); Tellier, L. L. (Larry L.); Ho, Cheng,

    2002-01-01T23:59:59.000Z

    At most optical wavelengths, laser light in a cloud lidar experiment is not absorbed but merely scattered out of the beam, eventually escaping the cloud via multiple scattering. There is much information available in this light scattered far from the input beam, information ignored by traditional 'on-beam' lidar. Monitoring these off-beam returns in a fully space- and time-resolved manner is the essence of our unique instrument, Wide Angle Imaging Lidar (WAIL). In effect, WAIL produces wide-field (60-degree full-angle) 'movies' of the scattering process and records the cloud's radiative Green functions. A direct data product of WAIL is the distribution of photon path lengths resulting from multiple scattering in the cloud. Following insights from diffusion theory, we can use the measured Green functions to infer the physical thickness and optical depth of the cloud layer, and, from there, estimate the volume-averaged liquid water content. WAIL is notable in that it is applicable to optically thick clouds, a regime in which traditional lidar is reduced to ceilometry. Here we present recent WAIL data oti various clouds and discuss the extension of WAIL to full diurnal monitoring by means of an ultra-narrow magneto-optic atomic line filter for daytime measurements.

  1. Measurements of Carbonaceous Aerosols using Semi-Continuous Thermal-Optical Method

    SciTech Connect (OSTI)

    Yu, Xiao-Ying

    2011-08-01T23:59:59.000Z

    Carbonaceous aerosols are major components in air pollution as a result of energy consumption, thus measurement of them is important to waste management. Increasing interest has been drawn to the identification, measurement, analysis, and modeling of carbon aerosols in the past decade. This book chapter will provide a review of current state-of-art techniques to determine carbonaceous aerosols in relation to air pollution and waste management. The chapter will be composed of four parts. The introduction will discuss why carbon aerosols including elemental carbon (EC), organic carbon (OC), and total carbon (TC=EC+OC) are important to energy consumption, air pollution, waste management, and global climate change. Key definitions will be introduced. Relevant terminologies will be provided. The second part will be a review of the current state-of the art measurement techniques that are used to determine carbon aerosols. Both on-line and off-line methods will be described. Comparisons of different techniques that provide the same physical quantity will be provided based on recent literature findings. Differences among the physical parameters determined by various techniques will be discussed. The third part will focus on data analysis and products obtained from carbon aerosol measurements. In addition to EC, OC, and TC, primary organic carbon (POC) and secondary organic carbon (SOC) are of interest to researchers to understand the source and sink of carbonaceous aerosols. Techniques used to determine POC and SOC, such as the EC tracer method and positive matrix factorization, will be described and their differences discussed. Examples will be provided showing field data comparison between the Sunset organic carbon and elemental carbon field analyzer and the Aerodyne aerosol mass spectrometer, both of which are widely used for on-line aerosol measurements. The last part will report new trends and summarize future research needs in carbon aerosol measurement. Emerging problems will be identified and research priorities will be recommended.

  2. 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.

  3. 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.

  4. EXERCISE-INDUCED ACUTE CHANGES IN SYSTOLIC BLOOD PRESSURE DO NOT ALTER CHOROIDAL THICKNESS AS MEASURED BY A PORTABLE SPECTRAL-DOMAIN OPTICAL COHERENCE TOMOGRAPHY DEVICE

    E-Print Network [OSTI]

    Alwassia, Ahmad A.

    Purpose: To measure choroidal thickness in patients manifesting an acute change in systemic arterial blood pressure using a portable spectral-domain optical coherence tomography device (iVue).

  5. Variations in organic aerosol optical and hygroscopic properties upon heterogeneous OH oxidation

    E-Print Network [OSTI]

    Cappa, Christopher D.

    Measurements of the evolution of organic aerosol extinction cross sections (?[subscript ext]) and subsaturated hygroscopicity upon heterogeneous OH oxidation are reported for two model compounds, squalane (a C30 saturated ...

  6. 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.

  7. 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

  8. 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

  9. 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

  10. 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.

  11. Using multi-angle, multispectral photo-polarimetry of the NASA Glory mission to constrain optical properties of aerosols and clouds: Results from

    E-Print Network [OSTI]

    Using multi-angle, multispectral photo-polarimetry of the NASA Glory mission to constrain optical Sensor (APS) for the determination of aerosol and cloud properties and a Total Irradiance Monitor (TIM (IFOV)instrument. The APS sensor will provide high-precision measurements of the total and polarized

  12. Jun Wang, Dept. Atmos. Sci., Univ. of AL in Huntsville December 25, 20031 Aerosol Optical Thickness Retrievals from

    E-Print Network [OSTI]

    Wang, Jun

    . Pollution from (coal burning) power plant Complex and Abundant Monthly mean AOT in Dunhuang in 2000 AOT(670/AATS 14) ­ (Dr. Phil Russell) Size distributions measured from a ground-based twin-scanning electrical

  13. 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...

  14. 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...

  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. Production Mechanism, Number Concentration, Size Distribution, Chemical Composition, and Optical Properties of Sea Spray Aerosols Workshop, Summer 2012

    SciTech Connect (OSTI)

    Meskhidze, Nicholas [NCSU] [NCSU

    2013-10-21T23:59:59.000Z

    The objective of this workshop was to address the most urgent open science questions for improved quantification of sea spray aerosol-radiation-climate interactions. Sea spray emission and its influence on global climate remains one of the most uncertain components of the aerosol-radiation-climate problem, but has received less attention than other aerosol processes (e.g. production of terrestrial secondary organic aerosols). Thus, the special emphasis was placed on the production flux of sea spray aerosol particles, their number concentration and chemical composition and properties.

  17. ALMA 690 GHz OBSERVATIONS OF IRAS 16293-2422B: INFALL IN A HIGHLY OPTICALLY THICK DISK

    SciTech Connect (OSTI)

    Zapata, Luis A.; Loinard, Laurent; Rodriguez, Luis F.; Hernandez-Hernandez, Vicente [Centro de Radioastronomia y Astrofisica, UNAM, Apdo. Postal 3-72 (Xangari), 58089 Morelia, Michoacan (Mexico); Takahashi, Satoko; Trejo, Alfonso [Academia Sinica Institute of Astronomy and Astrophysics, P.O. Box 23-141, Taipei 10617, Taiwan (China); Parise, Berengere [Max-Planck-Institut fuer Radioastronomie, Auf dem Huegel 69, D-53121 Bonn (Germany)

    2013-02-10T23:59:59.000Z

    We present sensitive, high angular resolution ({approx}0.''2) submillimeter continuum and line observations of IRAS 16293-2422B made with the Atacama Large Millimeter/Submillimeter Array. The 0.45 mm continuum observations reveal a single and very compact source associated with IRAS 16293-2422B. This submillimeter source has a deconvolved angular size of about 400 mas (50 AU) and does not show any inner structure inside of this diameter. The H{sup 13}CN, HC{sup 15}N, and CH{sub 3}OH line emission regions are about twice as large as the continuum emission and reveal a pronounced inner depression or ''hole'' with a size comparable to that estimated for the submillimeter continuum. We suggest that the presence of this inner depression and the fact that we do not see an inner structure (or a flat structure) in the continuum are produced by very optically thick dust located in the innermost parts of IRAS 16293-2422B. All three lines also show pronounced inverse P-Cygni profiles with infall and dispersion velocities larger than those recently reported from observations at lower frequencies, suggesting that we are detecting faster and more turbulent gas located closer to the central object. Finally, we report a small east-west velocity gradient in IRAS 16293-2422B that suggests that its disk plane is likely located very close to the plane of the sky.

  18. 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.

  19. 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.

  20. Correlations Between Optical, Chemical and Physical Properties...

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

    Correlations Between Optical, Chemical and Physical Properties of Biomass Burn Aerosols. Correlations Between Optical, Chemical and Physical Properties of Biomass Burn Aerosols....

  1. Photoacoustic optical properties at UV, VIS, and near IR wavelengths for laboratory generated and winter time ambient urban aerosols

    SciTech Connect (OSTI)

    Gyawali, Madhu S.; Arnott, W. Patrick; Zaveri, Rahul A.; Song, Chen; Moosmuller, H.; Liu, Li; Mishchenko, M.; Chen, L-W A.; Green, M.; Watson, J. G.; Chow, J. C.

    2012-03-08T23:59:59.000Z

    We present the laboratory and ambient photoacoustic (PA) measurement of aerosol light absorption coefficients at ultraviolet wavelength (i.e., 355 nm) and compare with measurements at 405, 532, 870, and 1047 nm. Simultaneous measurements of aerosol light scattering coefficients were achieved by the integrating reciprocal nephelometer within the PA's acoustic resonator. Absorption and scattering measurements were carried out for various laboratory generated aerosols, including salt, incense, and kerosene soot to evaluate the instrument calibration and gain insight on the spectral dependence of aerosol light absorption and scattering. Ambient measurements were obtained in Reno, Nevada, between 18 December 2009 and 18 January 2010. The measurement period included days with and without strong ground level temperature inversions, corresponding to highly polluted (freshly emitted aerosols) and relatively clean (aged aerosols) conditions. Particulate matter (PM) concentrations were measured and analyzed with other tracers of traffic emissions. The temperature inversion episodes caused very high concentration of PM{sub 2.5} and PM{sub 10} (particulate matter with aerodynamic diameters less than 2.5 {mu}m and 10 {mu}m, respectively) and gaseous pollutants: carbon monoxide (CO), nitric oxide (NO), and nitrogen dioxide (NO{sub 2}). The diurnal change of absorption and scattering coefficients during the polluted (inversion) days increased approximately by a factor of two for all wavelengths compared to the clean days. The spectral variation in aerosol absorption coefficients indicated a significant amount of absorbing aerosol from traffic emissions and residential wood burning. The analysis of single scattering albedo (SSA), Angstrom exponent of absorption (AEA), and Angstrom exponent of scattering (AES) for clean and polluted days provides evidences that the aerosol aging and coating process is suppressed by strong temperature inversion under cloudy conditions. In general, measured UV absorption coefficients were found to be much larger for biomass burning aerosol than for typical ambient aerosols.

  2. " Rotating, In Plane Magnetization and Magneto-Optic Imaging of Cracks in Thick-Section Steel Under Stainless-Steel Cladding".

    SciTech Connect (OSTI)

    Gerald Fitzpatrick & Richard Skaugset

    2000-10-13T23:59:59.000Z

    The nondestructive inspection (NDI) of thick-section steel nuclear reactor pressure vessels (RPV'S) is rendered difficult by rough stainless steel cladding. Because the cladding condition is poorly known in most RPV's, an NDI technique that is unaffected by cladding roughness would be a major advance. Magneto-optic imaging is one such technique. The purpose of this project was to develop a novel method to induce rotating, in-plane magnetization, and to combine this capability with magneto-optic imaging to produce a self-contained inspection system. Imaging of cracks under thick cladding (0.250 inches) was demonstrated using a system capable, in principle, of performing robotic inspections, both inside & outside a typical boiling water reactor (BWR) RPV. This report, together publications listed, constitutes a comprehensive account of this work.

  3. 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

  4. 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.

  5. 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

  6. An optimal fitting approach to improve the GISS ModelE aerosol optical property parameterization using AERONET data

    E-Print Network [OSTI]

    and absorbing solar radiation and the indirect effect by interacting with water vapor to affect cloud formation and lifetime. Absorbing aerosols also have the semidirect effect by heating the atmosphere layer, reducing; Intergovernmental Panel on Climate Change, 2001]. [3] Globalscale models, which simulate the emission, transport

  7. Niamey Aerosol Optical Depths

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

    Flynn, Connor

    MFRSR irradiance data collected during the ACRF AMF deployment in Niamey, Niger have been used to derive AOD for five wavelength channels of the MFRSR. These data have been corrected to adjust for filter drift over the course of the campaign and contamination due to forward scattering as a result of large dust particles in the atmosphere around Niamey.

  8. The impact of detailed urbanscale processing on the composition, distribution, and radiative forcing of anthropogenic aerosols

    E-Print Network [OSTI]

    forcing of anthropogenic aerosols Jason Blake Cohen,1,2 Ronald G. Prinn,1 and Chien Wang1 Received 11 model to simulate the effects of cities around the world on aerosol chemistry, physics, and radiative values of total aerosol surface concentration, the total aerosol column abundance, the aerosol optical

  9. 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.

  10. 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...

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

    SciTech Connect (OSTI)

    Jethva, H. T.; Torres, O.; Waquet, F.; Chand, Duli; Hu, Yong X.

    2014-01-16T23:59:59.000Z

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

  12. Annealing temperature and barrier thickness effect on the structural and optical properties of silicon nanocrystals/SiO{sub 2} superlattices

    SciTech Connect (OSTI)

    López-Vidrier, J., E-mail: jlopezv@el.ub.edu; Hernández, S.; López-Conesa, L.; Peiró, F.; Garrido, B. [MIND–IN2UB, Electronics Department, University of Barcelona, Martí i Franquès 1, E–08028 Barcelona (Spain); Hiller, D.; Gutsch, S.; Zacharias, M. [IMTEK, Faculty of Engineering, Albert-Ludwigs-University Freiburg, Georges-Köhler-Allee 103, D-79110 Freiburg (Germany); Estradé, S. [MIND–IN2UB, Electronics Department, University of Barcelona, Martí i Franquès 1, E–08028 Barcelona (Spain); TEM–MAT, CCiT–UB, Scientific and Technological Center - University of Barcelona, Solé i Sabarís 1, E–08028 Barcelona (Spain)

    2014-10-07T23:59:59.000Z

    The effect of the annealing temperature and the SiO{sub 2} barrier thickness of silicon nanocrystal (NC)/SiO{sub 2} superlattices (SLs) on their structural and optical properties is investigated. Energy-filtered transmission electron microscopy (TEM) revealed that the SL structure is maintained for annealing temperatures up to 1150?°C, with no variation on the nanostructure morphology for different SiO{sub 2} barrier thicknesses. Nevertheless, annealing temperatures as high as 1250?°C promote diffusion of Si atoms into the SiO{sub 2} barrier layers, which produces larger Si NCs and the loss of the NC size control expected from the SL approach. Complementary Raman scattering measurements corroborated these results for all the SiO{sub 2} and Si-rich oxynitride layer thicknesses. In addition, we observed an increasing crystalline fraction up to 1250?°C, which is related to a decreasing contribution of the suboxide transition layer between Si NCs and the SiO{sub 2} matrix due to the formation of larger NCs. Finally, photoluminescence measurements revealed that the emission of the superlattices exhibits a Gaussian-like lineshape with a maximum intensity after annealing at 1150?°C, indicating a high crystalline degree in good agreement with Raman results. Samples submitted to higher annealing temperatures display a progressive emission broadening, together with an increase in the central emission wavelength. Both effects are related to a progressive broadening of the size distribution with a larger mean size, in agreement with TEM observations. On the other hand, whereas the morphology of the Si NCs is unaffected by the SiO{sub 2} barrier thickness, the emission properties are slightly modified. These observed modifications in the emission lineshape allow monitoring the precipitation process of Si NCs in a direct non-destructive way. All these experimental results evidence that an annealing temperature of 1150?°C and 1-nm SiO{sub 2} barrier can be reached whilst preserving the SL structure, being thus the optimal structural SL parameters for their use in optoelectronics.

  13. Using In-Situ Aerosol Optical Properties to Develop a Novel Air Quality Monitoring and Diagnostic Tool

    E-Print Network [OSTI]

    Orcutt, John Michael

    2014-12-05T23:59:59.000Z

    and the optical properties were examined. Also, soot was used to generate ice crystals in the Texas A&M University Continuous Flow Diffusion Chamber (CFDC) which was used in conjunction with the CASPOL to measure the optical properties of ice nucleated on soot...

  14. 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...

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

    SciTech Connect (OSTI)

    Yang, Qing; Gustafson, William I.; Fast, Jerome D.; Wang, Hailong; Easter, Richard C.; Morrison, H.; Lee, Y.- N.; Chapman, Elaine G.; Spak, S. N.; Mena-Carrasco, M. A.

    2011-12-02T23:59:59.000Z

    In the recent chemistry version (v3.3) of the Weather Research and Forecasting (WRF-Chem) model, we have coupled the Morrison double-moment microphysics scheme with interactive aerosols so that full two-way aerosol-cloud interactions are included in simulations. We have used this new WRF-Chem functionality in a study focused on assessing predictions of aerosols, marine stratocumulus clouds, and their interactions over the Southeast Pacific using measurements from the VAMOS Ocean-Cloud-Atmosphere-Land Study Regional Experiment (VOCALS-REx) and satellite retrievals. This study also serves as a detailed analysis of our WRF-Chem simulations contributed to the VOCALS model Assessment (VOCA) project. The WRF-Chem 31-day (October 15-November 16, 2008) simulation with aerosol-cloud interactions (AERO hereafter) is also compared to a simulation (MET hereafter) with fixed cloud droplet number concentrations assumed by the default in Morrison microphysics scheme with no interactive aerosols. The well-predicted aerosol properties such as number, mass composition, and optical depth lead to significant improvements in many features of the predicted stratocumulus clouds: cloud optical properties and microphysical properties such as cloud top effective radius, cloud water path, and cloud optical thickness, and cloud macrostructure such as cloud depth and cloud base height. These improvements in addition to the aerosol direct and semi-direct effects, in turn, feed back to the prediction of boundary-layer characteristics and energy budgets. Particularly, inclusion of interactive aerosols in AERO strengths temperature and humidity gradients within capping inversion layer and lowers the MBL depth by 150 m from that of the MET simulation. Mean top-of-the-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 over the remote ocean) and aerosol quantities (e.g., overestimations of supermicron sea salt mass) might affect simulated stratocumulus and energy fluxes over the SEP, and require further investigations. Although not perfect, the overall performance of the regional model in simulating mesoscale aerosol-cloud interactions is encouraging and suggests that the inclusion of spatially varying aerosol characteristics is important when simulating marine stratocumulus over the southeastern Pacific.

  16. aerosol monitors including: Topics by E-print Network

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

    schemes which explicitly simulate the microphysical processes that determine the particle size distribution. These models enable aerosol optical ... Ridley, David Andrew 33...

  17. A 4-D Climatology (1979-2009) of the Monthly Tropospheric Aerosol Optical Depth Distribution over the Mediterranean Region from a Comparative Evaluation and Blending of Remote Sensing and Model Products

    SciTech Connect (OSTI)

    Nabat, P.; Somot, S.; Mallet, M.; Chiapello, I.; Morcrette, J. -J.; Solmon, F.; Szopa, S.; Dulac, F.; Collins, W.; Ghan, Steven J.; Horowitz, L.; Lamarque, J.-F.; Lee, Y. H.; Naik, Vaishali; Nagashima, T.; Shindell, Drew; Skeie, R. B.

    2013-05-17T23:59:59.000Z

    Since the 1980s several spaceborne sensors have been used to retrieve the aerosol optical depth (AOD) over the Mediterranean region. In parallel, AOD climatologies coming from different numerical model simulations are now also available, permitting to distinguish the contribution of several aerosol types to the total AOD. In this work, we perform a comparative analysis of this unique multiyear database in terms of total AOD and of its apportionment by the five main aerosol types (soil dust, seasalt, sulfate, black and organic carbon). We use 9 different satellite-derived monthly AOD products: NOAA/AVHRR, SeaWiFS (2 products), TERRA/MISR, TERRA/MODIS, AQUA/MODIS, ENVISAT/MERIS, PARASOL/POLDER and MSG/SEVIRI, as well as 3 more historical datasets: NIMBUS7/CZCS, TOMS (onboard NIMBUS7 and Earth- Probe) and METEOSAT/MVIRI. Monthly model datasets include the aerosol climatology from Tegen et al. (1997), the climate-chemistry models LMDz-OR-INCA and RegCM-4, the multi-model mean coming from the ACCMIP exercise, and the reanalyses GEMS and MACC. Ground-based Level- 2 AERONET AOD observations from 47 stations around the basin are used here to evaluate the model and satellite data. The sensor MODIS (on AQUA and TERRA) has the best average AOD scores over this region, showing a relevant spatiotemporal variability and highlighting high dust loads over Northern Africa and the sea (spring and summer), and sulfate aerosols over continental Europe (summer). The comparison also shows limitations of certain datasets (especially MERIS and SeaWiFS standard products). Models reproduce the main patterns of the AOD variability over the basin. The MACC reanalysis is the closest to AERONET data, but appears to underestimate dust over Northern Africa, where RegCM-4 is found closer to MODIS thanks to its interactive scheme for dust emissions. The vertical dimension is also investigated using the CALIOP instrument. This study confirms differences of vertical distribution between dust aerosols showing a large vertical spread, and other continental and marine aerosols which are confined in the boundary layer. From this compilation, we propose a 4-D blended product from model and satellite data, consisting in monthly time series of 3-D aerosol distribution at a 50 km horizontal resolution over the Euro-Mediterranean marine and continental region for the 2003–2009 period. The product is based on the total AOD from AQUA/MODIS, apportioned into sulfates, black and organic carbon from the MACC reanalysis, and into dust and sea-salt aerosols from RegCM-4 simulations, which are distributed vertically based on CALIOP climatology.We extend the 2003–2009 reconstruction to the past up to 1979 using the 2003–2009 average and applying the decreasing trend in sulfate aerosols from LMDz-OR-INCA, whose AOD trends over Europe and the Mediterranean are median among the ACCMIP models. Finally optical properties of the different aerosol types in this region are proposed from Mie calculations so that this reconstruction can be included in regional climate models for aerosol radiative forcing and aerosolclimate studies.

  18. 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...

  19. Controlling the crystallite size and influence of the film thickness on the optical and electrical characteristics of nanocrystalline Cu{sub 2}S films

    SciTech Connect (OSTI)

    Rafea, M. Abdel [Advanced Technology and New Material institute, City for Scientific Research and Technology Applications, New Borg El Arab City, Alexandria (Egypt)] [Advanced Technology and New Material institute, City for Scientific Research and Technology Applications, New Borg El Arab City, Alexandria (Egypt); Farag, A.A.M., E-mail: alaafaragg@yahoo.com [Thin Film Laboratory, Physics Department, Faculty of Education, Ain Shams University, Heliopolis, Roxy, Cairo 11757 (Egypt)] [Thin Film Laboratory, Physics Department, Faculty of Education, Ain Shams University, Heliopolis, Roxy, Cairo 11757 (Egypt); Roushdy, N. [Advanced Technology and New Material institute, City for Scientific Research and Technology Applications, New Borg El Arab City, Alexandria (Egypt)] [Advanced Technology and New Material institute, City for Scientific Research and Technology Applications, New Borg El Arab City, Alexandria (Egypt)

    2012-02-15T23:59:59.000Z

    Highlights: Black-Right-Pointing-Pointer Modification of the preparation technique in order to deposit nanostructure Cu{sub 2}S thin films. Black-Right-Pointing-Pointer Controlling the crystallite size of the prepared films. Black-Right-Pointing-Pointer Study the surface morphology, optical and electrical characteristics of Cu{sub 2}S films. -- Abstract: In this work, Cu{sub 2}S nanocrystalline films have been successfully prepared using dip-coating technique. The stoichiometry and the structural characteristics of the prepared films were characterized by energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD), respectively. The surface morphology of the deposited Cu{sub 2}S film was studied using both the scanning electron microscopy (SEM) and the atomic force microscopy (AFM). The SEM and AFM images indicate that the prepared Cu{sub 2}S films are characterized by a well-dispersed and highly dense with spherical like-shaped aggregates of size in the nano scale. The optical absorption measurements indicate that the Cu{sub 2}S nanoparticles have a direct band gap of 2.92 eV. The dispersion and absorption parameters such as the dispersion energy, oscillating energy, real and imaginary dielectric constants and dissipation factor were calculated within a wide wavelength range of the spectrum that indicates the suitability of the deposited films as solar absorber using this technique. The dark electrical resistivity ({rho}) measurements were carried out at different temperatures in the range 312-440 K. These results confirm the semiconducting characteristic of the prepared Cu{sub 2}S films. Moreover, two activation energies were obtained that indicate the presence of two dominating conduction mechanisms in these temperature ranges. The bulk electrical resistivity ({rho}{sub B}) and the mean free path (l{sub 0}) of charge carriers were estimated from the resistivity-thickness dependence. The heterojunction device of n-ZnCdS/p-Cu{sub 2}S behaves good rectifying property. The photovoltaic characteristic of the heterojunction device using the current-voltage characteristic under illumination of 100 mW/cm{sup 2} was also observed. Discussion of the obtained results and their comparison with the previous published data were also considered.

  20. 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

  1. 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.

  2. 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.

  3. Microphysical effects determine macrophysical response for aerosol impacts on deep

    E-Print Network [OSTI]

    Li, Zhanqing

    cloud cover, cloud top height, and radiative forcing. We found that although the widely accepted theory. The thermodynamic invigoration effect contrib- utes up to 27% of total increase in cloud cover. The overall aerosol by aerosols that drives the dramatic increase in cloud cover, cloud top height, and cloud thickness

  4. Modeling Space-Time Dynamics of Aerosols Using Satellite Data and Atmospheric Transport Model Output

    E-Print Network [OSTI]

    Shi, Tao

    Modeling Space-Time Dynamics of Aerosols Using Satellite Data and Atmospheric Transport Model of aerosol optical depth across mainland Southeast Asia. We include a cross validation study to assess

  5. Developing models of aerosol representation to investigate composition, evolution, optical properties, and CCN spectra using measurements of size-resolved hygroscopicity

    E-Print Network [OSTI]

    Gasparini, Roberto

    2006-08-16T23:59:59.000Z

    A Differential Mobility Analyzer/Tandem Differential Mobility Analyzer (DMA/TDMA) was used to measure size distributions, hygroscopicity, and volatility during the May 2003 Aerosol Intensive Operational Period at the Central Facility...

  6. Developing models of aerosol representation to investigate composition, evolution, optical properties, and CCN spectra using measurements of size-resolved hygroscopicity 

    E-Print Network [OSTI]

    Gasparini, Roberto

    2006-08-16T23:59:59.000Z

    A Differential Mobility Analyzer/Tandem Differential Mobility Analyzer (DMA/TDMA) was used to measure size distributions, hygroscopicity, and volatility during the May 2003 Aerosol Intensive Operational Period at the Central ...

  7. 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.

  8. 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...

  9. Dependences of the Al thickness and annealing temperature on the structural, optical and electrical properties in ZnO/Al multilayers

    E-Print Network [OSTI]

    Huang, Jung-Chun

    displays, electrochromic windows, electro-optical devices, gas sensors and solar cells. Nowadays, tin (TCO) films are currently of great commercial and scientific importance for applications in flat panel

  10. ARM - Measurement - Aerosol optical depth

    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 : XDC documentationBarrow, AlaskaWhenimage ARM Data Discovery

  11. ARM - Measurement - Aerosol optical properties

    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 : XDC documentationBarrow, AlaskaWhenimage ARM Data Discoveryproperties

  12. Reduction of Ground-Based Sensor Sites for Spatio-Temporal Analysis of Aerosols

    E-Print Network [OSTI]

    Vucetic, Slobodan

    Reduction of Ground-Based Sensor Sites for Spatio- Temporal Analysis of Aerosols Vladan in this study is estimation of an important property of atmosphere, called Aerosol Optical Depth (AOD). Remote of spatio- temporal aerosol patterns on a global scale. Ground-based AOD estimation is more accurate

  13. BNL -65518-AB UNCERTAINTIES IN CLIMATE FORCING BY ANTHROPOGENIC AEROSOLS

    E-Print Network [OSTI]

    the earth radiation budget and climate by scattering and absorbing shortwave radiation (direct effect), by modifying cloud shortwave and longwave optical properties (indirect effect), and by modifying cloud of these aerosols, as well as determination of the radiative influence of a specified well characterized aerosol

  14. Pavement Thickness Design Parameter

    E-Print Network [OSTI]

    Pavement Thickness Design Parameter Impacts 2012 Municipal Streets Seminar November 14, 2012 Paul D. Wiegand, P.E. #12;Pavement Thickness Design · How do cities decide how thick to build their pavements;Pavement Thickness Design · Correct answer ­ A data-based analysis! · Doesn't have to be difficult and time

  15. 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.

  16. 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.

  17. 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.

  18. System for measuring film thickness

    DOE Patents [OSTI]

    Batishko, Charles R. (West Richland, WA); Kirihara, Leslie J. (Richland, WA); Peters, Timothy J. (Richland, WA); Rasmussen, Donald E. (Richland, WA)

    1990-01-01T23:59:59.000Z

    A system for determining the thicknesses of thin films of materials exhibiting fluorescence in response to exposure to excitation energy from a suitable source of such energy. A section of film is illuminated with a fixed level of excitation energy from a source such as an argon ion laser emitting blue-green light. The amount of fluorescent light produced by the film over a limited area within the section so illuminated is then measured using a detector such as a photomultiplier tube. Since the amount of fluorescent light produced is a function of the thicknesses of thin films, the thickness of a specific film can be determined by comparing the intensity of fluorescent light produced by this film with the intensity of light produced by similar films of known thicknesses in response to the same amount of excitation energy. The preferred embodiment of the invention uses fiber optic probes in measuring the thicknesses of oil films on the operational components of machinery which are ordinarily obscured from view.

  19. 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...

  20. 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.

  1. Cloud seeding as a technique for studying aerosol-cloud interactions in marine stratocumulus

    E-Print Network [OSTI]

    Miami, University of

    Cloud seeding as a technique for studying aerosol-cloud interactions in marine stratocumulus hygroscopic aerosols were introduced into a solid marine stratocumulus cloud (200 m thick) by burning hygroscopic flares mounted on an aircraft. The cloud microphysical response in two parallel seeding plumes

  2. 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

  3. Regional variation of organic functional groups in aerosol particles on four U.S. east coast platforms during the International Consortium for

    E-Print Network [OSTI]

    and secondary organic aerosol (SOA) formation. SOA can be formed by condensation of species produced by gas aerosol mass spectrometers for OM, a Sunset Laboratory thermo-optical analysis instrument for OC

  4. 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.

  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. 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.

  7. Thick film hydrogen sensor

    DOE Patents [OSTI]

    Hoffheins, Barbara S. (Knoxville, TN); Lauf, Robert J. (Oak Ridge, TN)

    1995-01-01T23:59:59.000Z

    A thick film hydrogen sensor element includes an essentially inert, electrically-insulating substrate having deposited thereon a thick film metallization forming at least two resistors. The metallization is a sintered composition of Pd and a sinterable binder such as glass frit. An essentially inert, electrically insulating, hydrogen impermeable passivation layer covers at least one of the resistors.

  8. 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.

  9. 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

  10. Aerosol Retrievals from ARM SGP MFRSR Data

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

    Alexandrov, Mikhail

    The Multi-Filter Rotating Shadowband Radiometer (MFRSR) makes precise simultaneous measurements of the solar direct normal and diffuse horizontal irradiances at six wavelengths (nominally 415, 500, 615, 673, 870, and 940 nm) at short intervals (20 sec for ARM instruments) throughout the day. Time series of spectral optical depth are derived from these measurements. Besides water vapor at 940 nm, the other gaseous absorbers within the MFRSR channels are NO2 (at 415, 500, and 615 nm) and ozone (at 500, 615, and 670 nm). Aerosols and Rayleigh scattering contribute atmospheric extinction in all MFRSR channels. Our recently updated MFRSR data analysis algorithm allows us to partition the spectral aerosol optical depth into fine and coarse modes and to retrieve the fine mode effective radius. In this approach we rely on climatological amounts of NO2 from SCIAMACHY satellite retrievals and use daily ozone columns from TOMS.

  11. 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.

  12. 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

  13. 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

  14. 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

  15. 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.

  16. 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.

  17. 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

  18. 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.

  19. Reply to Quaas et al.: Can satellites be used to estimate indirect climate forcing by aerosols?

    SciTech Connect (OSTI)

    Penner, J. E.; Zhou, Cheng; Xu, Li; Wang, Minghuai

    2011-11-15T23:59:59.000Z

    We welcome the comments by Quaas et al. (1). In our paper (2), we used a model to show that the methods used to estimate indirect aerosol forcing using satellite data, especially those based on relating the slope of present-day (PD) drop number (Nc) to aerosol optical depth (AOD), underestimate the forcing calculated when both PD and preindustrial (PI) data are available.

  20. Carbonaceous Aerosols and Radiative Effects Study (CARES), g1-aircraft, sedlacek sp2

    SciTech Connect (OSTI)

    Sedlacek, Art

    2011-08-30T23:59:59.000Z

    The primary objective of the Carbonaceous Aerosol and Radiative Effects Study (CARES) in 2010 was to investigate the evolution of carbonaceous aerosols of different types and their optical and hygroscopic properties in central California, with a focus on the Sacramento urban plume.

  1. 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

  2. Point and column aerosol radiative closure during ACE 1: Effects of particle shape and size

    E-Print Network [OSTI]

    impact the earth's climate and photo- chemistry by directly scattering and absorbing solar radia- tion these impacts [e.g., Intergovernmental Panel on Climate Change, 2001]. Because of the short temporal and spatial scales of aerosol heterogeneity, numerical models of aerosol optical behavior are required to make

  3. Carbonaceous Aerosols and Radiative Effects Study (CARES), g1-aircraft, sedlacek sp2

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

    Sedlacek, Art

    The primary objective of the Carbonaceous Aerosol and Radiative Effects Study (CARES) in 2010 was to investigate the evolution of carbonaceous aerosols of different types and their optical and hygroscopic properties in central California, with a focus on the Sacramento urban plume.

  4. 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.

  5. 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.

  6. 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

  7. 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 ...

  8. The Effects of Black Carbon and Sulfate Aerosols in ChinaRegions on East Asia Monsoons

    SciTech Connect (OSTI)

    Yang, Bai [ORNL; Liu, Yu [Chinese Academy of Meteorological Sciences, Beijing, China; Sun, Jiaren [South China Institute of Environmental Sciences, Guangzhou, China

    2009-01-01T23:59:59.000Z

    In this paper we examine the direct effects of sulfate and black carbon aerosols in China on East Asia monsoons and its precipitation processes by using the CAM3.0 model. It is demonstrated that sulfate and black carbon aerosols in China both have the effects to weaken East Asia monsoons in both summer and winter seasons. However, they certainly differ from each other in affecting vertical structures of temperature and atmospheric circulations. Their differences are expected because of their distinct optical properties, i.e., scattering vs. absorbing. Even for a single type of aerosol, its effects on temperature structures and atmospheric circulations are largely season-dependent. Applications of T-test on our results indicate that forcing from black carbon aerosols over China is relatively weak and limited. It is also evident from our results that the effects of synthetic aerosols (sulfate and black carbon together) on monsoons are not simply a linear summation between these two types of aerosols. Instead, they are determined by their integrated optical properties. Synthetic aerosols to a large degree resemble effects of sulfate aerosols. This implies a likely scattering property for the integration of black carbon and sulfate aerosols in China.

  9. Atmospheric optical calibration system

    DOE Patents [OSTI]

    Hulstrom, Roland L. (Bloomfield, CO); Cannon, Theodore W. (Golden, CO)

    1988-01-01T23:59:59.000Z

    An atmospheric optical calibration system is provided to compare actual atmospheric optical conditions to standard atmospheric optical conditions on the basis of aerosol optical depth, relative air mass, and diffuse horizontal skylight to global horizontal photon flux ratio. An indicator can show the extent to which the actual conditions vary from standard conditions. Aerosol scattering and absorption properties, diffuse horizontal skylight to global horizontal photon flux ratio, and precipitable water vapor determined on a real-time basis for optical and pressure measurements are also used to generate a computer spectral model and for correcting actual performance response of a photovoltaic device to standard atmospheric optical condition response on a real-time basis as the device is being tested in actual outdoor conditions.

  10. Atmospheric optical calibration system

    DOE Patents [OSTI]

    Hulstrom, R.L.; Cannon, T.W.

    1988-10-25T23:59:59.000Z

    An atmospheric optical calibration system is provided to compare actual atmospheric optical conditions to standard atmospheric optical conditions on the basis of aerosol optical depth, relative air mass, and diffuse horizontal skylight to global horizontal photon flux ratio. An indicator can show the extent to which the actual conditions vary from standard conditions. Aerosol scattering and absorption properties, diffuse horizontal skylight to global horizontal photon flux ratio, and precipitable water vapor determined on a real-time basis for optical and pressure measurements are also used to generate a computer spectral model and for correcting actual performance response of a photovoltaic device to standard atmospheric optical condition response on a real-time basis as the device is being tested in actual outdoor conditions. 7 figs.

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

    SciTech Connect (OSTI)

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

    2014-09-30T23:59:59.000Z

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

  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. 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....

  15. 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

  16. 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

  17. 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

  18. 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.

  19. SCIAMACHY'S ABSORBING AEROSOL INDEX AND THE CONSEQUENCES OF INSTRUMENT DEGRADATION

    E-Print Network [OSTI]

    Tilstra, Gijsbert

    SCIAMACHY'S ABSORBING AEROSOL INDEX AND THE CONSEQUENCES OF INSTRUMENT DEGRADATION L. G. Tilstra1 a strong increase in the AAI with time, which is found to be caused completely by degradation of the optics. This we conclude from straightforward calculation of the effect of instrument degradation based

  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. 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.

  2. 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.

  3. 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...

  4. Critical thickness in silicone thermosets

    E-Print Network [OSTI]

    Deopura, Manish, 1975-

    2005-01-01T23:59:59.000Z

    Critical thickness effects are utilized to achieve high fracture toughness in brittle polymers. The postulate of critical thickness, which is: "Macroscopically brittle polymers deform in a ductile fashion below a critical ...

  5. 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

  6. 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.

  7. 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

  8. 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.

  9. 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

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

    SciTech Connect (OSTI)

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

    2014-05-13T23:59:59.000Z

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

  11. Thick beryllium coatings by magnetron sputtering

    SciTech Connect (OSTI)

    Wu, H; Nikroo, A; Youngblood, K; Moreno, K; Wu, D; Fuller, T; Alford, C; Hayes, J; Detor, A; Wong, M; Hamza, A; van Buuren, T; Chason, E

    2011-04-14T23:59:59.000Z

    Thick (>150 {micro}m) beryllium coatings are studied as an ablator material of interest for fusion fuel capsules for the National Ignition Facility (NIF). As an added complication, the coatings are deposited on mm-scale spherical substrates, as opposed to flats. DC magnetron sputtering is used because of the relative controllability of the processing temperature and energy of the deposits. We used ultra small angle x-ray spectroscopy (USAXS) to characterize the void fraction and distribution along the spherical surface. We investigated the void structure using a combination focused ion beam (FIB) and scanning electron microscope (SEM), along with transmission electron microscopy (TEM). Our results show a few volume percent of voids and a typical void diameter of less than two hundred nanometers. Understanding how the stresses in the deposited material develop with thickness is important so that we can minimize film cracking and delamination. To that end, an in-situ multiple optical beam stress sensor (MOSS) was used to measure the stress behavior of thick Beryllium coatings on flat substrates as the material was being deposited. We will show how the film stress saturates with thickness and changes with pressure.

  12. Final Technical Report [Toward Simultaneous Single-Particle Chemical and Optical Characterization: Development of a Multi-Angle Optical Scattering Module for the Aerosol Time-of-Flight Mass Spectrometer

    SciTech Connect (OSTI)

    Buckley, Steven [Photon Machines, Inc.] [Photon Machines, Inc.

    2013-10-22T23:59:59.000Z

    This project was an initial effort to investigate the feasibility of an instrument combining real-time atmospheric particle composition measurements using an ATOFMS (Atmospheric Time-Of-Flight Mass Spectrometer) such as those performed by Prather’s group at the University of California, San Diego (UCSD) with multi-wavelength scattering measurements of the type investigated by Sorensen et al., of Kansas State University (KSU). In this Phase I effort we proposed to investigate near-angle scattering and the possibility of integration of a multi-wavelength scattering instrument into the UCSD ATOFMS. After an initial optical design and calculations, we discovered issues with the theory of measurement and with mechanical integration. Evidence emerged that the method of multi-wavelength scattering is only efficacious for spherical particles, while most atmospheric particles are non-spherical fractal aggregates. We also determined that the integration of the detector into existing ATOFMS instruments would be severely limited by volume constraints, and additional volume would require prohibitive additional pumping compared with the existing ATOFMS systems. Based on this evidence, we decided not to pursue a Phase II effort.

  13. 8, 161179, 2008 UV Aerosol Optical

    E-Print Network [OSTI]

    Boyer, Edmond

    'Optique Atmosph´erique (LOA), Universit´e des Sciences et Technologies de Lille, 59655 Villeneuve d'Ascq Cedex, France 2 Interactions Rayonnement Solaire Atmosph`ere (IRSA), Universit´e Joseph Fourier de Grenoble, 17

  14. Optical Properties of Secondary Organic Aerosols

    E-Print Network [OSTI]

    Kim, Hwajin

    2012-01-01T23:59:59.000Z

    oxygen (0.5 L/min) through a mercury lamp O 3 generator (oxygen (0.5 L/min) through a mercury lamp O 3 generator (

  15. ARM - Field Campaign - MASRAD - Aerosol Optical Properties

    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- Polarization Diversity Lidar (PDL) Campaign Links M-PACE Website ARM Data

  16. ARM - PI Product - Niamey Aerosol Optical Depths

    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 : XDCnarrowbandheatProductsISDAC MicrophysicsProductsNauru

  17. 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

  18. 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.

  19. 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)...

  20. 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...

  1. 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.

  2. Soot particle aerosol dynamics at high pressure

    SciTech Connect (OSTI)

    Harris, S.J. (General Motors Research Labs., Warren, MI (USA). Physics Dept.); Kennedy, I.M. (California Univ., Davis, CA (USA). Dept. of Mechanical Engineering)

    1989-12-01T23:59:59.000Z

    The authors have used detailed calculations to analyze the coagulation dynamics of a soot aerosol at high pressures (20 and 50 atm). They find that the soot size distribution is altered compared to lower-pressure conditions because the mean free path at high pressures is reduced to the point that the particles are similar in size to the mean free path. At lower pressures the form of the size distribution becomes constant (self-preserving) in time, allowing optical measurements to be easily interpreted. However, the authors find that at pressures above about 5 atm the shape of the size distribution continually changes. As a result, proper and accurate interpretation of optical data at high pressures is more difficult than at lower pressures.

  3. 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.

  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. 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.

  6. 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

  7. 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

  8. 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

  9. 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

  10. 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

  11. Aerosols and clouds in chemical transport models and climate models.

    SciTech Connect (OSTI)

    Lohmann,U.; Schwartz, S. E.

    2008-03-02T23:59:59.000Z

    Clouds exert major influences on both shortwave and longwave radiation as well as on the hydrological cycle. Accurate representation of clouds in climate models is a major unsolved problem because of high sensitivity of radiation and hydrology to cloud properties and processes, incomplete understanding of these processes, and the wide range of length scales over which these processes occur. Small changes in the amount, altitude, physical thickness, and/or microphysical properties of clouds due to human influences can exert changes in Earth's radiation budget that are comparable to the radiative forcing by anthropogenic greenhouse gases, thus either partly offsetting or enhancing the warming due to these gases. Because clouds form on aerosol particles, changes in the amount and/or composition of aerosols affect clouds in a variety of ways. The forcing of the radiation balance due to aerosol-cloud interactions (indirect aerosol effect) has large uncertainties because a variety of important processes are not well understood precluding their accurate representation in models.

  12. 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

  13. The Nearby Supernova Factory Ozone + Aerosol + Rayleigh

    E-Print Network [OSTI]

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

  14. Laser detection of material thickness

    DOE Patents [OSTI]

    Early, James W. (Los Alamos, NM)

    2002-01-01T23:59:59.000Z

    There is provided a method for measuring material thickness comprising: (a) contacting a surface of a material to be measured with a high intensity short duration laser pulse at a light wavelength which heats the area of contact with the material, thereby creating an acoustical pulse within the material: (b) timing the intervals between deflections in the contacted surface caused by the reverberation of acoustical pulses between the contacted surface and the opposite surface of the material: and (c) determining the thickness of the material by calculating the proportion of the thickness of the material to the measured time intervals between deflections of the contacted surface.

  15. 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.

  16. 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

  17. 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...

  18. 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...

  19. 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...

  20. 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...

  1. 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...

  2. 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.

  3. 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

  4. Climate Impacts of Atmospheric Sulfate and Black Carbon Aerosols

    SciTech Connect (OSTI)

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

    2008-09-19T23:59:59.000Z

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

  5. Influence of the SiO{sub 2} interlayer thickness on the density and polarity of charges in Si/SiO{sub 2}/Al{sub 2}O{sub 3} stacks as studied by optical second-harmonic generation

    SciTech Connect (OSTI)

    Terlinden, N. M.; Dingemans, G.; Vandalon, V.; Bosch, R. H. E. C.; Kessels, W. M. M., E-mail: w.m.m.kessels@tue.nl [Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands)

    2014-01-21T23:59:59.000Z

    By accurately tuning the SiO{sub 2} interlayer thickness the density and polarity of charges in Si/SiO{sub 2}/Al{sub 2}O{sub 3} stacks can be controlled. We report on the number density, polarity, and physical location of charges present in the stacks as studied by optical second-harmonic generation (SHG). Depending on the SiO{sub 2} interlayer thickness (1–150?nm) the effective charge density in the Si/SiO{sub 2}/Al{sub 2}O{sub 3} stacks ranges from 10{sup 13} to 10{sup 11}?cm{sup ?2} for both n- and p-type silicon. The polarity of the charges switches from negative to positive around a SiO{sub 2} interlayer thickness of 5–10?nm at which point the effective charge density in the stacks is negligible. This switch in polarity is apparent from spectroscopic, time-dependent, and azimuthal SHG measurements. The observed trends in charge density and polarity can be explained by tunneling of electrons into defect states at the SiO{sub 2}/Al{sub 2}O{sub 3} interface as well as the presence of fixed and bulk charges at the Si/SiO{sub 2} interface and in the SiO{sub 2}, respectively. This charge mechanism appears to hold generally for Si/SiO{sub 2}/Al{sub 2}O{sub 3} stacks as similar results were observed for SiO{sub 2} films prepared by various techniques.

  6. 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...

  7. 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

  8. 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

  9. 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

  10. X-ray Vision for Aerosol Scientists: LCLS Snapshots of Soot (Narrated)

    ScienceCinema (OSTI)

    None

    2014-06-03T23:59:59.000Z

    This short conceptual animation depicts how scientists can now simultaneously capture fractal morphology (structure), chemical composition and nanoscale imagery of individual aerosol particles in flight. These particles, known as "PM2.5" because they are smaller than 2.5 microns in diameter, affect climate by interacting with sunlight and impact human health by entering the lungs. The single LCLS laser pulses travel to the Atomic, Molecular and Optical Sciences (AMO) laboratory in the Near Experimental Hall. As we zoom in, we see deep inside a simplified aerosol inlet, where the complex fractal structure of the soot particles, each one completely unique, is shown. Individual soot particles are then delivered into the pulses of the LCLS beam, which destroys them. X-rays are scattered to the detector before the particle is destroyed, giving information about the morphology of the particle. Ion fragments released in the explosion are sent into a mass spectrometer, which measures their mass-to-charge ratio -- giving scientists information about the chemical composition of the particle. Many different particles are analyzed in this manner, allowing scientists to probe variations in the particles due to changes in their environment before being sent through the aerosol inlet. The final visual of aerosols emitted from a factory is representative of the goal that such LCLS aerosol dynamics experiments can provide critical feedback into modeling and understanding combustion, aerosol processes in manufacturing or aerosol effects on climate change.

  11. X-ray Vision for Aerosol Scientists: LCLS Snapshots of Soot (Narrated)

    SciTech Connect (OSTI)

    None

    2012-10-22T23:59:59.000Z

    This short conceptual animation depicts how scientists can now simultaneously capture fractal morphology (structure), chemical composition and nanoscale imagery of individual aerosol particles in flight. These particles, known as "PM2.5" because they are smaller than 2.5 microns in diameter, affect climate by interacting with sunlight and impact human health by entering the lungs. The single LCLS laser pulses travel to the Atomic, Molecular and Optical Sciences (AMO) laboratory in the Near Experimental Hall. As we zoom in, we see deep inside a simplified aerosol inlet, where the complex fractal structure of the soot particles, each one completely unique, is shown. Individual soot particles are then delivered into the pulses of the LCLS beam, which destroys them. X-rays are scattered to the detector before the particle is destroyed, giving information about the morphology of the particle. Ion fragments released in the explosion are sent into a mass spectrometer, which measures their mass-to-charge ratio -- giving scientists information about the chemical composition of the particle. Many different particles are analyzed in this manner, allowing scientists to probe variations in the particles due to changes in their environment before being sent through the aerosol inlet. The final visual of aerosols emitted from a factory is representative of the goal that such LCLS aerosol dynamics experiments can provide critical feedback into modeling and understanding combustion, aerosol processes in manufacturing or aerosol effects on climate change.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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

  17. 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

  18. 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

  19. 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

  20. 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

  1. 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

  2. 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

  3. 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

  4. 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

  5. Method and system for producing sputtered thin films with sub-angstrom thickness uniformity or custom thickness gradients

    DOE Patents [OSTI]

    Folta, James A. (2262 Hampton Rd., Livermore, CA 94550); Montcalm, Claude (14 Jami St., Livermore, CA 94550); Walton, Christopher (2927 Lorina St., #2, Berkeley, CA 94705-1852)

    2003-01-01T23:59:59.000Z

    A method and system for producing a thin film with highly uniform (or highly accurate custom graded) thickness on a flat or graded substrate (such as concave or convex optics), by sweeping the substrate across a vapor deposition source with controlled (and generally, time-varying) velocity. In preferred embodiments, the method includes the steps of measuring the source flux distribution (using a test piece that is held stationary while exposed to the source), calculating a set of predicted film thickness profiles, each film thickness profile assuming the measured flux distribution and a different one of a set of sweep velocity modulation recipes, and determining from the predicted film thickness profiles a sweep velocity modulation recipe which is adequate to achieve a predetermined thickness profile. Aspects of the invention include a practical method of accurately measuring source flux distribution, and a computer-implemented method employing a graphical user interface to facilitate convenient selection of an optimal or nearly optimal sweep velocity modulation recipe to achieve a desired thickness profile on a substrate. Preferably, the computer implements an algorithm in which many sweep velocity function parameters (for example, the speed at which each substrate spins about its center as it sweeps across the source) can be varied or set to zero.

  6. 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

  7. Hybrid Optical Pumping of Optically Dense Alkali-Metal Vapor without Quenching Gas M. V. Romalis

    E-Print Network [OSTI]

    Romalis, Mike

    Hybrid Optical Pumping of Optically Dense Alkali-Metal Vapor without Quenching Gas M. V. Romalis; published 7 December 2010) Optical pumping of an optically thick atomic vapor typically requires a quenching the atoms. We show that optical pumping of a trace contamination of Rb present in K metal results in a 4

  8. The effects of emission of anthropogenic chemical species on chemical and physical properties of aerosols

    SciTech Connect (OSTI)

    Lee, In Young

    1994-07-01T23:59:59.000Z

    Numerical studies have been carried out to examine the effects of chemically reactive trace gases emitted into the atmosphere on the evolution of chemical species concentrations, on the chemical composition and size distribution of airborne particles, and on optical properties of aerosols. Argonne`s chemistry module has been modified by refining the treatment of gas-to-particle conversion. The changes in size distribution and chemical composition of aerosols are calculated with consideration of heteramolecular diffusion and coagulation. Results of the 24 h real-time simulation indicate that the maximum oxidation rate of sulfur dioxide is about 0.4% h{sup {minus}1}; that the total aerosol volume increases with the increase in relative humidity by as much as 36% (due mainly to the collection of sulfuric acid embryos by preexisting particles); and that the surface area, a measure of optical depth, increases with the increase in relative humidity by as much as 27%.

  9. Aerosol chemical vapor deposition of metal oxide films

    DOE Patents [OSTI]

    Ott, Kevin C. (4745 Trinity Dr., Los Alamos, NM 87544); Kodas, Toivo T. (5200 Noreen Dr. NE., Albuquerque, NM 87111)

    1994-01-01T23:59:59.000Z

    A process of preparing a film of a multicomponent metal oxide including: forming an aerosol from a solution comprised of a suitable solvent and at least two precursor compounds capable of volatilizing at temperatures lower than the decomposition temperature of said precursor compounds; passing said aerosol in combination with a suitable oxygen-containing carrier gas into a heated zone, said heated zone having a temperature sufficient to evaporate the solvent and volatilize said precursor compounds; and passing said volatilized precursor compounds against the surface of a substrate, said substrate having a sufficient temperature to decompose said volatilized precursor compounds whereby metal atoms contained within said volatilized precursor compounds are deposited as a metal oxide film upon the substrate is disclosed. In addition, a coated article comprising a multicomponent metal oxide film conforming to the surface of a substrate selected from the group consisting of silicon, magnesium oxide, yttrium-stabilized zirconium oxide, sapphire, or lanthanum gallate, said multicomponent metal oxide film characterized as having a substantially uniform thickness upon said FIELD OF THE INVENTION The present invention relates to the field of film coating deposition techniques, and more particularly to the deposition of multicomponent metal oxide films by aerosol chemical vapor deposition. This invention is the result of a contract with the Department of Energy (Contract No. W-7405-ENG-36).

  10. 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...

  11. Aerosol size distribution evolution in large area fire plumes

    SciTech Connect (OSTI)

    Porch, W.M.; Penner, J.E.

    1986-09-01T23:59:59.000Z

    Large fires are significant seasonal contributors to western visibility reduction. We have found that the relative concentration of supermicron size particles (assumed to be a mixture of mechanically generated particles by high winds associated with large fires and low density chain aggregates from coagulation in the fire) and high turbulence in fire plumes can radically change the aerosol sizes in the fire plume. This is especially important for aerosols with high visibility reduction and long range transport potential. This calculation was done with a 10 level one dimensional model with parameterized vertical and horizontal diffusion, sedimentation and coagulation. The optical effects of the evolving concentration and size distributions were modeled using Mie scattering and absorption assumptions.

  12. Lyman alpha Transfer in a thick, dusty, and static medium

    E-Print Network [OSTI]

    Sang-Hyeon Ahn; Hee-Won Lee; Hyung-Mok Lee

    2000-06-13T23:59:59.000Z

    We developed a Monte Carlo code that describes the resonant Lyman alpha line transfer in an optically thick, dusty, and static medium. The code was tested against the analytic formula derived by Neufeld (1990). We explain the line transfer mechanism for a wide range of line center optical depths by tracing histories of photons in the medium. We find that photons escape from the medium by a series of wing scatterings, during which polarization may develop. We applied our code to examine the amount of dust extinction around the Lyman alpha in primeval galaxies. Brief discussions on the astrophysical application of our work are presented.

  13. 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

  14. 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

  15. 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.

  16. 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

  17. 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

  18. Light Trapping Textures Designed by Electromagnetic Optimization for Sub-Wavelength Thick Solar Cells

    E-Print Network [OSTI]

    California at Irvine, University of

    the surface of the solar cell, where n is the material refractive index. This ray-optics absorption enhancement limit only holds when the thickness of the solar cell is much greater than the optical wavelength limit of 4n2 50. Introduction Texturing of solar cell surfaces allows for absorption enhancement, owing

  19. 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.

  20. MASS SPECTROMETRIC APPROACHES FOR CHEMICAL CHARACTERISATION OF ATMOSPHERIC AEROSOLS: CRITICAL REVIEW OF MOST RECENT ADVANCES

    SciTech Connect (OSTI)

    Laskin, Alexander; Laskin, Julia; Nizkorodov, Sergey

    2012-06-29T23:59:59.000Z

    This manuscript presents an overview of the most recent instrument developments, field and laboratory applications of mass spectrometry (MS) in chemistry and physics of atmospheric aerosols. A broad range of MS instruments employing different sample introduction methods, ionization and mass detection techniques are utilized for both “on?line” and “off?line” characterization of aerosols. On?line MS techniques enable detection of individual particles with simultaneous measurements of particle size distributions and aerodynamic characteristics, and are ideally suited for field studies which require high temporal resolution. Off?line MS techniques provide means for detailed molecular?level analysis of aerosol samples which is essential to fundamental knowledge on aerosol chemistry, mechanisms of particle formation and atmospheric aging. Combined together, complementary MS techniques provide comprehensive information on the chemical composition, size, morphology and phase of aerosols ? data of key importance for evaluating hygroscopic and optical properties of particles, their health effects, understanding their origins, and atmospheric evolution. Developments and applications of MS techniques in the aerosol research have expanded remarkably over a couple of last years as evidenced by sky?rocketing publication statistics. The goal of this review is to period of late 2010 ? early2012, which were not conveyed in previous reviews.

  1. Investigation of multiple scattering effects in aerosols. Final report, Sep 1978 - Dec 1979

    SciTech Connect (OSTI)

    Deepak, A.

    1980-05-01T23:59:59.000Z

    The results are presented of investigations on the various aspects of multiple scattering effects on visible and infrared laser beams transversing dense fog oil aerosols contained in a chamber (4' x 4' x 9'). The report briefly describes: (1) the experimental details and measurements (2) analytical representation of the aerosol size distribution data by two analytical models (the regularized power law distribution and the inverse modified gamma distribution) (3) retrieval of aerosol size distributions from multispectral optical depth measurements by two methods (the two and three parameter fast table search methods and the nonlinear least squares method) (4) modeling of the effects of aerosol microphysical (coagulation and evaporation) and dynamical processes (gravitational settling) on the temporal behavior of aerosol size distribution, and hence on the extinction of four laser beams with wavelengths 0.44, 0.6328, 1.15, and 3.39 micrometers and (5) the exact and approximate formulations for four methods for computing the effects of multiple scattering on the transmittance of laser beams in dense aerosols, all of which are based on the solution of the radiative transfer equation under the small angle approximation.

  2. Production flux of sea spray aerosol

    SciTech Connect (OSTI)

    de Leeuw, G.; Lewis, E.; Andreas, E. L.; Anguelova, M. D.; Fairall, C. W.; O’Dowd, C.; Schulz, M.; Schwartz, S. E.

    2011-05-07T23:59:59.000Z

    Knowledge of the size- and composition-dependent production flux of primary sea spray aerosol (SSA) particles and its dependence on environmental variables is required for modeling cloud microphysical properties and aerosol radiative influences, interpreting measurements of particulate matter in coastal areas and its relation to air quality, and evaluating rates of uptake and reactions of gases in sea spray drops. This review examines recent research pertinent to SSA production flux, which deals mainly with production of particles with r{sub 80} (equilibrium radius at 80% relative humidity) less than 1 {micro}m and as small as 0.01 {micro}m. Production of sea spray particles and its dependence on controlling factors has been investigated in laboratory studies that have examined the dependences on water temperature, salinity, and the presence of organics and in field measurements with micrometeorological techniques that use newly developed fast optical particle sizers. Extensive measurements show that water-insoluble organic matter contributes substantially to the composition of SSA particles with r{sub 80} < 0.25 {micro}m and, in locations with high biological activity, can be the dominant constituent. Order-of-magnitude variation remains in estimates of the size-dependent production flux per white area, the quantity central to formulations of the production flux based on the whitecap method. This variation indicates that the production flux may depend on quantities such as the volume flux of air bubbles to the surface that are not accounted for in current models. Variation in estimates of the whitecap fraction as a function of wind speed contributes additional, comparable uncertainty to production flux estimates.

  3. 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.

  4. 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

  5. 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

  6. 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

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

    SciTech Connect (OSTI)

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

    2009-04-10T23:59:59.000Z

    Aerosol indirect effects continue to constitute one of the most important uncertainties for anthropogenic climate perturbations. Within the international AEROCOM initiative, the representation of aerosol-cloud-radiation interactions in ten different general circulation models (GCMs) is evaluated using three satellite datasets. The focus is on stratiform liquid water clouds since most GCMs do not include ice nucleation effects, and none of the model explicitly parameterizes aerosol effects on convective clouds. We compute statistical relationships between aerosol optical depth (Ta) and various cloud and radiation quantities in a manner that is consistent between the models and the satellite data. It is found that the model-simulated influence of aerosols on cloud droplet number concentration (Nd) compares relatively well to the satellite data at least over the ocean. The relationship between Ta and liquid water path is simulated much too strongly by the models. It is shown that this is partly related to the representation of the second aerosol indirect effect in terms of autoconversion. A positive relationship between total cloud fraction (fcld) and Ta as found in the satellite data is simulated by the majority of the models, albeit less strongly than that in the satellite data in most of them. In a discussion of the hypotheses proposed in the literature to explain the satellite-derived strong fcld - Ta relationship, our results indicate that none can be identified as unique explanation. Relationships similar to the ones found in satellite data between Ta and cloud top temperature or outgoing long-wave radiation (OLR) are simulated by only a few GCMs. The GCMs that simulate a negative OLR - Ta relationship show a strong positive correlation between Ta and fcld The short-wave total aerosol radiative forcing as simulated by the GCMs is strongly influenced by the simulated anthropogenic fraction of Ta, and parameterisation assumptions such as a lower bound on Nd. Nevertheless, the strengths of the statistical relationships are good predictors for the aerosol forcings in the models. An estimate of the total short-wave aerosol forcing inferred from the combination of these predictors for the modelled forcings with the satellite-derived statistical relationships yields a global annual mean value of -1.5+-0.5 Wm-2. An alternative estimate obtained by scaling the simulated clear- and cloudy-sky forcings with estimates of anthropogenic Ta and satellite-retrieved Nd - Ta regression slopes, respectively, yields a global annual mean clear-sky (aerosol direct effect) estimate of -0.4+-0.2 Wm-2 and a cloudy-sky (aerosol indirect effect) estimate of -0.7+-0.5 Wm-2, with a total estimate of -1.2+-0.4 Wm-2.

  8. Direct Aerosol Forcing: Sensitivity to Uncertainty in Measurements of

    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 AdministrationField Campaign: Potential ApplicationYu,EnergyDimitriDiracAerosol Optical and

  9. 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

  10. 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

  11. 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

  12. 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

  13. Method and system using power modulation and velocity modulation producing sputtered thin films with sub-angstrom thickness uniformity or custom thickness gradients

    DOE Patents [OSTI]

    Montcalm, Claude (Livermore, CA); Folta, James Allen (Livermore, CA); Walton, Christopher Charles (Berkeley, CA)

    2003-12-23T23:59:59.000Z

    A method and system for determining a source flux modulation recipe for achieving a selected thickness profile of a film to be deposited (e.g., with highly uniform or highly accurate custom graded thickness) over a flat or curved substrate (such as concave or convex optics) by exposing the substrate to a vapor deposition source operated with time-varying flux distribution as a function of time. Preferably, the source is operated with time-varying power applied thereto during each sweep of the substrate to achieve the time-varying flux distribution as a function of time. Preferably, the method includes the steps of measuring the source flux distribution (using a test piece held stationary while exposed to the source with the source operated at each of a number of different applied power levels), calculating a set of predicted film thickness profiles, each film thickness profile assuming the measured flux distribution and a different one of a set of source flux modulation recipes, and determining from the predicted film thickness profiles a source flux modulation recipe which is adequate to achieve a predetermined thickness profile. Aspects of the invention include a computer-implemented method employing a graphical user interface to facilitate convenient selection of an optimal or nearly optimal source flux modulation recipe to achieve a desired thickness profile on a substrate. The method enables precise modulation of the deposition flux to which a substrate is exposed to provide a desired coating thickness distribution.

  14. IFE thick liquid wall chamber dynamics: Governing mechanisms andmodeling and experimental capabilities

    SciTech Connect (OSTI)

    Raffray, A.R.; Meier, W.; Abdel-Khalik, S.; Bonazza, R.; Calderoni, P.; Debonnel, C.S.; Dragojlovic, Z.; El-Guebaly, L.; Haynes,D.; Latkowski, J.; Olson, C.; Peterson, P.F.; Reyes, S.; Sharpe, P.; Tillack, M.S.; Zaghloul, M.

    2005-01-24T23:59:59.000Z

    For thick liquid wall concepts, it is important to understand the different mechanisms affecting the chamber dynamics and the state of the chamber prior to each shot a compared with requirements from the driver and target. These include ablation mechanisms, vapor transport and control, possible aerosol formation, as well as protective jet behavior. This paper was motivated by a town meeting on this subject which helped identify the major issues, assess the latest results, review the capabilities of existing modeling and experimental facilities with respect to addressing remaining issues, and helping guide future analysis and R&D efforts; the paper covers these exact points.

  15. 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.

  16. 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...

  17. 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,...

  18. 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...

  19. 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...

  20. 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...

  1. 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...

  2. 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:...

  3. 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...

  4. 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...

  5. 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...

  6. 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...

  7. 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...

  8. 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...

  9. 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...

  10. 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...

  11. 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.

  12. 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...

  13. 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.

  14. 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...

  15. 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...

  16. 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...

  17. 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;...

  18. 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;...

  19. 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;...

  20. 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;...

  1. 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;...

  2. 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;...

  3. 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;...

  4. 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...

  5. 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;...

  6. 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,...

  7. 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;...

  8. 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.

  9. Infrared Transmissometer to Measure the Thickness of NbN Thin Films

    E-Print Network [OSTI]

    Sunter, Kristen A; Lang, Christopher I; Berggren, Karl K

    2015-01-01T23:59:59.000Z

    We present an optical setup that can be used to characterize the thicknesses of thin NbN films to screen samples for fabrication and to better model the performance of the resulting superconducting nanowire single photon detectors. The infrared transmissometer reported here is easy to use, gives results within minutes and is non-destructive. Thus, the thickness measurement can be easily integrated into the workflow of deposition and characterization. Comparison to a similar visible-wavelength transmissometer is provided.

  10. 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.

  11. 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.

  12. 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.

  13. 2254 IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING, VOL. 42, NO. 10, OCTOBER 2004 Retrieval of Semitransparent Ice Cloud Optical

    E-Print Network [OSTI]

    Li, Jun

    of Semitransparent Ice Cloud Optical Thickness From Atmospheric Infrared Sounder (AIRS) Measurements Heli Wei, Ping Abstract--An approach is developed to infer the optical thick- ness of semitransparent ice clouds (when optical thickness is less than 5) from Atmospheric Infrared Sounder (AIRS) high spectral resolution

  14. Aerosol chemical vapor deposition of metal oxide films

    DOE Patents [OSTI]

    Ott, K.C.; Kodas, T.T.

    1994-01-11T23:59:59.000Z

    A process of preparing a film of a multicomponent metal oxide including: forming an aerosol from a solution comprised of a suitable solvent and at least two precursor compounds capable of volatilizing at temperatures lower than the decomposition temperature of said precursor compounds; passing said aerosol in combination with a suitable oxygen-containing carrier gas into a heated zone, said heated zone having a temperature sufficient to evaporate the solvent and volatilize said precursor compounds; and passing said volatilized precursor compounds against the surface of a substrate, said substrate having a sufficient temperature to decompose said volatilized precursor compounds whereby metal atoms contained within said volatilized precursor compounds are deposited as a metal oxide film upon the substrate is disclosed. In addition, a coated article comprising a multicomponent metal oxide film conforming to the surface of a substrate selected from the group consisting of silicon, magnesium oxide, yttrium-stabilized zirconium oxide, sapphire, or lanthanum gallate, said multicomponent metal oxide film characterized as having a substantially uniform thickness upon said substrate.

  15. 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...

  16. 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

  17. 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

  18. 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

  19. 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

  20. 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.

  1. 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

  2. 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

  3. 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

  4. 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

  5. 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(

  6. 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:

  7. 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

  8. 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

  9. 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

  10. 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

  11. 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

  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. 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.

  14. 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.

  15. 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.

  16. Simultaneous Retrieval of Effective Refractive Index and Density from Size Distribution and Light Scattering Data: Weakly-Absorbing Aerosol

    SciTech Connect (OSTI)

    Kassianov, Evgueni I.; Barnard, James C.; Pekour, Mikhail S.; Berg, Larry K.; Shilling, John E.; Flynn, Connor J.; Mei, Fan; Jefferson, Anne

    2014-10-01T23:59:59.000Z

    We propose here a novel approach for retrieving in parallel the effective density and real refractive index of weakly absorbing aerosol from optical and size distribution measurements. Here we define “weakly absorbing” as aerosol single-scattering albedos that exceed 0.95 at 0.5 um.The required optical measurements are the scattering coefficient and the hemispheric backscatter fraction, obtained in this work from an integrating nephelometer. The required size spectra come from a Scanning Mobility Particle Sizer and an Aerodynamic Particle Sizer. The performance of this approach is first evaluated using a sensitivity study with synthetically generated but measurement-related inputs. The sensitivity study reveals that the proposed approach is robust to random noise; additionally the uncertainties of the retrieval are almost linearly proportional to the measurement errors, and these uncertainties are smaller for the real refractive index than for the effective density. Next, actual measurements are used to evaluate our approach. These measurements include the optical, microphysical, and chemical properties of weakly absorbing aerosol which are representative of a variety of coastal summertime conditions observed during the Two-Column Aerosol Project (TCAP; http://campaign.arm.gov/tcap/). The evaluation includes calculating the root mean square error (RMSE) between the aerosol characteristics retrieved by our approach, and the same quantities calculated using the conventional volume mixing rule for chemical constituents. For dry conditions (defined in this work as relative humidity less than 55%) and sub-micron particles, a very good (RMSE~3%) and reasonable (RMSE~28%) agreement is obtained for the retrieved real refractive index (1.49±0.02) and effective density (1.68±0.21), respectively. Our approach permits discrimination between the retrieved aerosol characteristics of sub-micron and sub-10micron particles. The evaluation results also reveal that the retrieved density and refractive index tend to decrease with an increase of the relative humidity.

  17. Embedding metal electrodes in thick active layers for ITO-free plasmonic organic solar cells

    E-Print Network [OSTI]

    Park, Namkyoo

    Embedding metal electrodes in thick active layers for ITO-free plasmonic organic solar cells%) in optical absorption over both a conventional ITO organic solar cell and a conventional plasmonic organic solar cell with top-loaded metallic grating is predicted in the proposed structure. Optimal positioning

  18. 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.

  19. 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...

  20. Turbine airfoil with outer wall thickness indicators

    DOE Patents [OSTI]

    Marra, John J; James, Allister W; Merrill, Gary B

    2013-08-06T23:59:59.000Z

    A turbine airfoil usable in a turbine engine and including a depth indicator for determining outer wall blade thickness. The airfoil may include an outer wall having a plurality of grooves in the outer surface of the outer wall. The grooves may have a depth that represents a desired outer surface and wall thickness of the outer wall. The material forming an outer surface of the outer wall may be removed to be flush with an innermost point in each groove, thereby reducing the wall thickness and increasing efficiency. The plurality of grooves may be positioned in a radially outer region of the airfoil proximate to the tip.

  1. 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

  2. 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:...

  3. 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.

  4. 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

  5. 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.

  6. 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...

  7. 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...

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

    SciTech Connect (OSTI)

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

    2006-05-18T23:59:59.000Z

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

  9. Properties of micrometer-thick plasma-polymerized tetrafluoroethylene films

    SciTech Connect (OSTI)

    Butler, M.A.; Buss, R.J.; Galuska, A. (Sandia National Laboratories, Albuquerque, New Mexico (USA))

    1991-08-15T23:59:59.000Z

    Several physical properties of thin plasma-polymerized films have been measured using a new fiber-optic-based technique. Films of plasma-polymerized tetrafluoroethylene (PPTFE) deposited on the end of an optical fiber form an optical cavity, the reflectivity of which is very sensitive to the film thickness. The fiber is used as an {ital in} {ital situ} monitor of the deposition rate in the plasma and, after removal from the plasma, the mechanical properties of the film can be measured. With this measurement technique the thermal expansion of the film normal to its surface as well as the swelling of the film when exposed to an array of organic solvents have been determined. A significantly smaller thermal-expansion coefficient and larger degree of swelling are observed relative to bulk PTFE. X-ray photoelectron spectroscopy measurements show that the fluorocarbon chains are highly branched and have a fluorine-to-carbon ratio of 1.45. These results suggest that the plasma-polymerized films are not crystalline and are heavily cross linked.

  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 caliper with compensation for specimen deflection and method

    DOE Patents [OSTI]

    Bernacki, B.E.

    1997-12-09T23:59:59.000Z

    An optical non-contact profilometry system and method provided by an optical caliper with matched optical sensors that are arranged conjugate to each other so that the surface profile and thickness of an article can be measured without using a fixed reference surface and while permitting the article to deflect in space within the acquisition range of the optical sensors. The output signals from the two optical sensors are algebraically added to compensate for any such deflection of the article and provide a so compensated signal, the balance and sign of which provides a measurement of the actual thickness of the article at the optical sensors. 2 figs.

  12. Optical caliper with compensation for specimen deflection and method

    DOE Patents [OSTI]

    Bernacki, Bruce E. (Knoxville, TN)

    1997-01-01T23:59:59.000Z

    An optical non-contact profilometry system and method provided by an optical caliper with matched optical sensors that are arranged conjugate to each other so that the surface profile and thickness of an article can be measured without using a fixed reference surface and while permitting the article to deflect in space within the acquisition range of the optical sensors. The output signals from the two optical sensors are algebraically added to compensate for any such deflection of the article and provide a so compensated signal, the balance and sign of which provides a measurement of the actual thickness of the article at the optical sensors.

  13. atmospheric aerosol optical: Topics by E-print Network

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

    Size Distribution Physics (arXiv) Summary: Atmospheric flows exhibit selfsimilar fractal spacetime fluctuations manifested as the fractal geometry to global cloud cover...

  14. Rattlesnake Mountain Observator (46.4{degrees}N, 119.6{degrees}W) multispectral optical depth measurements, 1979--1994

    SciTech Connect (OSTI)

    Daniels, R.C. [ed.] [ed.

    1995-09-22T23:59:59.000Z

    Surface measurements of solar irradiance of the atmosphere were made by a multipurpose computer-controlled scanning photometer at the Rattlesnake Mountain Observatory. The observatory is located at 46.4{degrees}N, 119.6{degrees}W at an elevation of 1088 m above mean sea level. The photometer measures the attenuation of direct solar radiation for different wavelengths using 12 filters. Five of these filters (ie., at 428 nm, 486 nm, 535 nm, 785 nm, and 1010 nm, with respective half-power widths of 2, 2, 3, 18, and 28 nm) are suitable for monitoring variations in the total optical depth of the atmosphere. Total optical depths for the five wavelength bands were derived from solar irradiance measurements taken at the observatory from August 5, 1979, to September 2, 1994; these total optical depth data are distributed with this numeric data package (NDP). To determine the contribution of atmospheric aerosols to the total optical depths, the effects of Rayleigh scattering and ozone absorption were subtracted (other molecular scattering was minimal for the five filters) to obtain total column aerosol optical depths. The total aerosol optical depths were further decomposed into tropospheric and stratospheric components by calculating a robustly smoothed mean background optical depth (tropospheric component) for each wavelength using data obtained during periods of low stratospheric aerosol loading. By subtracting the smoothed background tropospheric aerosol optical depths from the total aerosol optical depths, residual aerosol optical depths were obtained. These residuals are good estimates of the stratospheric aerosol optical depth at each wavelength and may be used to monitor the long-term effects of volcanic eruptions on the atmosphere. These data are available as an NDP from the Carbon Dioxide Information Analysis Center (CDIAC), and the NDP consists of this document and a set of computerized data files.

  15. IFE thick liquid wall chamber dynamics: Governing mechanisms and modeling and experimental capabilities

    E-Print Network [OSTI]

    2005-01-01T23:59:59.000Z

    in the aerosol size distribution due to coagulation andCoagulation changes the size distribution a number of 1 ptm aerosolCoagulation changes the size distribution a number of 1 pirn aerosol

  16. 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.

  17. 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

  18. 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.

  19. 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

  20. Atmospheric Radiation Measurement (ARM) Data from Shouxian, China for the Study of Aerosol Indirect Effects in China

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

    In a complex ARM Mobile Facility (AMF) deployment, monitoring data was collected at four locations in China during 2008. The various sites are located in regions with different climate regimes and with high aerosol loadings of different optical, physical, and chemical properties. Measurements obtained at all the AMF sites during the 8-month deployment in China will help scientists to validate satellite-based findings, understand the mechanisms of the aerosol indirect effects in the region, and examine the roles of aerosols in affecting regional climate and atmospheric circulation, with a special focus on the impact of the East Asian monsoon system. As with other collections from the ARM Mobile Facility, the datasets are available from the ARM Archive. The ARM Archive physically resides at the Oak Ridge National Laboratory.

  1. Systematic Evaluation of Jc Decrease in Thick Film Coated Conductors

    SciTech Connect (OSTI)

    Alex Ignatiev; Dr. Amit Goyal

    2006-05-10T23:59:59.000Z

    Address both thickness dependence of Jc, in thick film YBCO coated conductors through an application of a suite of new measurement techniques to thick film wire samples produced by commercially viable coated conductor technologies.

  2. 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.

  3. Thin, thick and dark discs in LCDM

    E-Print Network [OSTI]

    J. I. Read; G. Lake; O. Agertz; Victor P. Debattista

    2008-06-26T23:59:59.000Z

    In a LCDM cosmology, the Milky Way accretes satellites into the stellar disc. We use cosmological simulations to assess the frequency of near disc plane and higher inclination accretion events, and collisionless simulations of satellite mergers to quantify the final state of the accreted material and the effect on the thin disc. On average, a Milky Way-sized galaxy has 3 subhalos with vmax>80km/s; 7 with vmax>60km/s; and 15 with vmax>40km/s merge at redshift z>1. Assuming isotropic accretion, a third of these merge at an impact angle disc plane by dynamical friction. Their accreted stars and dark matter settle into a thick disc. The stellar thick disc qualitatively reproduces the observed thick disc at the solar neighbourhood, but is less massive by a factor ~2-10. The dark matter disc contributes 0.25-1 times the halo density at the solar position. Although not likely to be dynamically interesting, the dark disc has important implications for the direct detection of dark matter because of its low velocity with respect to the Earth. Higher inclination encounters (>20 degrees) are twice as likely as low inclination ones. These lead to structures that closely resemble the recently discovered inner/outer stellar halos. They also do more damage to the Milky Way stellar disc creating a more pronounced flare, and warp; both long-lived and consistent with current observations. The most massive mergers (vmax>80km/s) heat the thin disc enough to produce a thick disc. These heated thin disc stars are essential for obtaining a thick disc as massive as that seen in the Milky Way; they likely comprise some ~50-90% of the thick disc stars. The Milky Way thin disc must reform from fresh gas after z=1 [abridged].

  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. 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...

  10. 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...

  11. 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...

  12. Co layer thickness dependence of exchange biasing for IrMnCo and FeMnCo

    E-Print Network [OSTI]

    Reilly, Anne

    Co layer thickness dependence of exchange biasing for IrMnÕCo and FeMnÕCo K. A. Seua) and H. Huang) in IrMn/Co and FeMn/Co bilayers using the magneto-optical Kerr effect. Samples are sputtered wedges on silicon with Co thicknesses ranging from 1 to 17 nm. The IrMn/Co with exchange bias interface energy of 0

  13. Gas turbine bucket wall thickness control

    DOE Patents [OSTI]

    Stathopoulos, Dimitrios (Glenmont, NY); Xu, Liming (Greenville, SC); Lewis, Doyle C. (Greer, SC)

    2002-01-01T23:59:59.000Z

    A core for use in casting a turbine bucket including serpentine cooling passages is divided into two pieces including a leading edge core section and a trailing edge core section. Wall thicknesses at the leading edge and the trailing edge of the turbine bucket can be controlled independent of each other by separately positioning the leading edge core section and the trailing edge core section in the casting die. The controlled leading and trailing edge thicknesses can thus be optimized for efficient cooling, resulting in more efficient turbine operation.

  14. Effect of Thickness on the Structure, Composition and Properties...

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

    Effect of Thickness on the Structure, Composition and Properties of Titanium Nitride Nano-Coatings. Effect of Thickness on the Structure, Composition and Properties of Titanium...

  15. 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.

  16. 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...

  17. Sulfuric acid deposition from stratospheric geoengineering with sulfate aerosols

    E-Print Network [OSTI]

    Robock, Alan

    aerosols can potentially result in an increase in acid deposition. [4] Acid rain has been studiedSulfuric acid deposition from stratospheric geoengineering with sulfate aerosols Ben Kravitz,1 Alan limit of hydration of all sulfate aerosols into sulfuric acid. For annual injection of 5 Tg of SO2

  18. Volume 8 No.1 -Summer 2011 Science & Aerosols

    E-Print Network [OSTI]

    Chen, Ying

    Volume 8 No.1 - Summer 2011 1 Science & Aerosols How advances in spectroscopy may change climate clues to galaxy formation 04Science & Aerosols How advances in spectroscopy may change climate science. No university buildings were injured in the making of this photo! #12;Volume 8 No.1 - Summer 2011 5 &aerosols

  19. SUNLIGHT TRANSMISSION THROUGH DESERT DUST AND MARINE AEROSOLS: DIFFUSE LIGHT

    E-Print Network [OSTI]

    SUNLIGHT TRANSMISSION THROUGH DESERT DUST AND MARINE AEROSOLS: DIFFUSE LIGHT CORRECTIONS TO SUN transmission through desert dust and marine aerosols: Diffuse light corrections to Sun photometry 2004; published 27 April 2004. [1] Desert dust and marine aerosols are receiving increased scientific

  20. Surface figure control for coated optics

    DOE Patents [OSTI]

    Ray-Chaudhuri, Avijit K. (Livermore, CA); Spence, Paul A. (Pleasanton, CA); Kanouff, Michael P. (Livermore, CA)

    2001-01-01T23:59:59.000Z

    A pedestal optical substrate that simultaneously provides high substrate dynamic stiffness, provides low surface figure sensitivity to mechanical mounting hardware inputs, and constrains surface figure changes caused by optical coatings to be primarily spherical in nature. The pedestal optical substrate includes a disk-like optic or substrate section having a top surface that is coated, a disk-like base section that provides location at which the substrate can be mounted, and a connecting cylindrical section between the base and optics or substrate sections. The optic section has an optical section thickness.sup.2 /optical section diameter ratio of between about 5 to 10 mm, and a thickness variation between front and back surfaces of less than about 10%. The connecting cylindrical section may be attached via three spaced legs or members. However, the pedestal optical substrate can be manufactured from a solid piece of material to form a monolith, thus avoiding joints between the sections, or the disk-like base can be formed separately and connected to the connecting section. By way of example, the pedestal optical substrate may be utilized in the fabrication of optics for an extreme ultraviolet (EUV) lithography imaging system, or in any optical system requiring coated optics and substrates with reduced sensitivity to mechanical mounts.

  1. Free Energy of thick Center Vortices

    E-Print Network [OSTI]

    Ch. Korn; H. Reinhardt; T. Tok

    2005-08-05T23:59:59.000Z

    The free energy of thick center vortices is calculated in continuum Yang-Mills theory in one-loop approximation using the proper time regularization. The vortices are represented by Abelian gauge field configurations on the torus which satisfy twisted boundary conditions.

  2. Can aerosols be trapped in open flows?

    E-Print Network [OSTI]

    Rafael D. Vilela; Adilson E. Motter

    2008-01-22T23:59:59.000Z

    The fate of aerosols in open flows is relevant in a variety of physical contexts. Previous results are consistent with the assumption that such finite-size particles always escape in open chaotic advection. Here we show that a different behavior is possible. We analyze the dynamics of aerosols both in the absence and presence of gravitational effects, and both when the dynamics of the fluid particles is hyperbolic and nonhyperbolic. Permanent trapping of aerosols much heavier than the advecting fluid is shown to occur in all these cases. This phenomenon is determined by the occurrence of multiple vortices in the flow and is predicted to happen for realistic particle-fluid density ratios.

  3. Phase transformation and growth of hygroscopic aerosols

    SciTech Connect (OSTI)

    Tang, I.N.

    1999-11-01T23:59:59.000Z

    Ambient aerosols play an important role in many atmospheric processes affecting air quality, visibility degradation, and climatic changes as well. Both natural and anthropogenic sources contribute to the formation of ambient aerosols, which are composed mostly of sulfates, nitrates, and chlorides in either pure or mixed forms. These inorganic salt aerosols are hygroscopic by nature and exhibit the properties of deliquescence and efflorescence in humid air. For pure inorganic salt particles with diameter larger than 0.1 micron, the phase transformation from a solid particle to a saline droplet occurs only when the relative humidity in the surrounding atmosphere reaches a certain critical level corresponding to the water activity of the saturated solution. The droplet size or mass in equilibrium with relative humidity can be calculated in a straightforward manner from thermodynamic considerations. For aqueous droplets 0.1 micron or smaller, the surface curvature effect on vapor pressure becomes important and the Kelvin equation must be used.

  4. CADS:Cantera Aerosol Dynamics Simulator.

    SciTech Connect (OSTI)

    Moffat, Harry K.

    2007-07-01T23:59:59.000Z

    This manual describes a library for aerosol kinetics and transport, called CADS (Cantera Aerosol Dynamics Simulator), which employs a section-based approach for describing the particle size distributions. CADS is based upon Cantera, a set of C++ libraries and applications that handles gas phase species transport and reactions. The method uses a discontinuous Galerkin formulation to represent the particle distributions within each section and to solve for changes to the aerosol particle distributions due to condensation, coagulation, and nucleation processes. CADS conserves particles, elements, and total enthalpy up to numerical round-off error, in all of its formulations. Both 0-D time dependent and 1-D steady state applications (an opposing-flow flame application) have been developed with CADS, with the initial emphasis on developing fundamental mechanisms for soot formation within fires. This report also describes the 0-D application, TDcads, which models a time-dependent perfectly stirred reactor.

  5. 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

  6. A study of the direct and indirect effects of aerosols using global satellite data sets of aerosol and cloud parameters

    E-Print Network [OSTI]

    Daniel, Rosenfeld

    regions consistent with the global mean statistics. However, the effective cloud particle radius showedA study of the direct and indirect effects of aerosols using global satellite data sets of aerosol between aerosol and cloud parameters derived from satellite remote sensing for evaluating the radiative

  7. Optical Fibers Optics and Photonics

    E-Print Network [OSTI]

    Palffy-Muhoray, Peter

    Optical Fibers Optics and Photonics Dr. Palffy-Muhoray Ines Busuladzic Department of Theoretical and Applied Mathematics The University of Akron April 21, 2008 #12;Outline · History of optical fibers · What are optical fibers? · How are optical fibers made? · Light propagation through optical fibers · Application

  8. Apparatus for sampling and characterizing aerosols

    DOE Patents [OSTI]

    Dunn, Patrick F. (Downers Grove, IL); Herceg, Joseph E. (Naperville, IL); Klocksieben, Robert H. (Park Forest, IL)

    1986-01-01T23:59:59.000Z

    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 to the next. Mounted within each collection stage are one or more particle collection frames.

  9. Aerodynamic Focusing Of High-Density Aerosols

    SciTech Connect (OSTI)

    Ruiz, D. E.; Fisch, Nathaniel

    2014-02-24T23:59:59.000Z

    High-density micron-sized particle aerosols might form the basis for a number of applications in which a material target with a particular shape might be quickly ionized to form a cylindrical or sheet shaped plasma. A simple experimental device was built in order to study the properties of high-density aerosol focusing for 1#22; m silica spheres. Preliminary results recover previous findings on aerodynamic focusing at low densities. At higher densities, it is demonstrated that the focusing properties change in a way which is consistent with a density dependent Stokes number.

  10. Near real time vapor detection and enhancement using aerosol adsorption

    DOE Patents [OSTI]

    Novick, V.J.; Johnson, S.A.

    1999-08-03T23:59:59.000Z

    A vapor sample detection method is described where the vapor sample contains vapor and ambient air and surrounding natural background particles. The vapor sample detection method includes the steps of generating a supply of aerosol that have a particular effective median particle size, mixing the aerosol with the vapor sample forming aerosol and adsorbed vapor suspended in an air stream, impacting the suspended aerosol and adsorbed vapor upon a reflecting element, alternatively directing infrared light to the impacted aerosol and adsorbed vapor, detecting and analyzing the alternatively directed infrared light in essentially real time using a spectrometer and a microcomputer and identifying the vapor sample. 13 figs.

  11. Near real time vapor detection and enhancement using aerosol adsorption

    DOE Patents [OSTI]

    Novick, Vincent J. (Downers Grove, IL); Johnson, Stanley A. (Countryside, IL)

    1999-01-01T23:59:59.000Z

    A vapor sample detection method where the vapor sample contains vapor and ambient air and surrounding natural background particles. The vapor sample detection method includes the steps of generating a supply of aerosol that have a particular effective median particle size, mixing the aerosol with the vapor sample forming aerosol and adsorbed vapor suspended in an air stream, impacting the suspended aerosol and adsorbed vapor upon a reflecting element, alternatively directing infrared light to the impacted aerosol and adsorbed vapor, detecting and analyzing the alternatively directed infrared light in essentially real time using a spectrometer and a microcomputer and identifying the vapor sample.

  12. 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, ...

  13. Pretest aerosol code comparisons for LWR aerosol containment tests LA1 and LA2

    SciTech Connect (OSTI)

    Wright, A.L.; Wilson, J.H.; Arwood, P.C.

    1986-01-01T23:59:59.000Z

    The Light-Water-Reactor (LWR) Aerosol Containment Experiments (LACE) are being performed in Richland, Washington, at the Hanford Engineering Development Laboratory (HEDL) under the leadership of an international project board and the Electric Power Research Institute. These tests have two objectives: (1) to investigate, at large scale, the inherent aerosol retention behavior in LWR containments under simulated severe accident conditions, and (2) to provide an experimental data base for validating aerosol behavior and thermal-hydraulic computer codes. Aerosol computer-code comparison activities are being coordinated at the Oak Ridge National Laboratory. For each of the six LACE tests, ''pretest'' calculations (for code-to-code comparisons) and ''posttest'' calculations (for code-to-test data comparisons) are being performed. The overall goals of the comparison effort are (1) to provide code users with experience in applying their codes to LWR accident-sequence conditions and (2) to evaluate and improve the code models.

  14. Two Hundred Fifty Years of Aerosols and Climate: The End of the Age of Aerosols

    SciTech Connect (OSTI)

    Smith, Steven J.; Bond, Tami C.

    2014-01-20T23:59:59.000Z

    Carbonaceous and sulfur aerosols have a substantial global and regional influence on climate in addition to their impact on health and ecosystems. The magnitude of this influence has changed substantially over the past and is expected to continue to change into the future. An integrated picture of the changing climatic influence of black carbon, organic carbon and sulfate over the period 1850 through 2100, focusing on uncertainty, is presented using updated historical inventories and a coordinated set of emission projections. While aerosols have had a substantial impact on climate over the past century, by the end of the 21st century aerosols will likely be only a minor contributor to radiative forcing due to increases in greenhouse gas forcing and a global decrease in pollutant emissions. This outcome is even more certain under a successful implementation of a policy to limit greenhouse gas emissions as low-carbon energy technologies that do not emit appreciable aerosol or SO2 are deployed.

  15. Aerosol Science and Technology, 44:329338, 2010 Copyright American Association for Aerosol Research

    E-Print Network [OSTI]

    Dabdub, Donald

    for Photochemical and Thermal Studies of Tropospheric Aerosols Michael J. Ezell,1 Stanley N. Johnson,1 Yong Yu,2 V of the UCI Physical Sciences Machine Shop; and J¨org Meyer of the UCI Chemistry Department Glassblow- ing

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

    SciTech Connect (OSTI)

    Song, Chen; Zaveri, Rahul A.; Alexander, M. Lizabeth; Thornton, Joel A.; Madronich, Sasha; Ortega, John V.; Zelenyuk, Alla; Yu, Xiao-Ying; Laskin, Alexander; Maughan, A. D.

    2007-10-16T23:59:59.000Z

    Semi-empirical secondary organic aerosol (SOA) models typically assume a well-mixed organic aerosol phase even in the presence of hydrophobic primary organic aerosols (POA). This assumption significantly enhances the modeled SOA yields as additional organic mass is made available to absorb greater amounts of oxidized secondary organic gases than otherwise. We investigate the applicability of this critical assumption by measuring SOA yields from ozonolysis of ?-pinene (a major biogenic SOA precursor) in a smog chamber in the absence and in the presence of dioctyl phthalate (DOP) and lubricating oil seed aerosol. These particles serve as surrogates for urban hydrophobic POA. The results show that these POA did not enhance the SOA yields. If these results are found to apply to other biogenic SOA precursors, then the semi-empirical models used in many global models would predict significantly less biogenic SOA mass and display reduced sensitivity to anthropogenic POA emissions than previously thought.

  17. High-speed non-contact measuring apparatus for gauging the thickness of moving sheet material

    DOE Patents [OSTI]

    Grann, Eric B. (San Ramon, CA); Holcomb, David E. (Oak Ridge, TN)

    2000-01-01T23:59:59.000Z

    An optical measurement apparatus is provided for measuring the thickness of a moving sheet material (18). The apparatus has a pair of optical measurement systems (21, 31) attached to opposing surfaces (14, 16) of a rigid support structure (10). A pair of high-power laser diodes (20,30) and a pair of photodetector arrays (22,32) are attached to the opposing surfaces. Light emitted from the laser diodes is reflected off of the sheet material surfaces (17, 19) and received by the respective photodetector arrays. An associated method for implementing the apparatus is also provided.

  18. Status of the ORNL Aerosol Release and Transport Project

    SciTech Connect (OSTI)

    Adams, R.E.

    1985-01-01T23:59:59.000Z

    The behavior of aerosols assumed to be characteristic of those generated during light water reactor (LWR) accident sequences and released into containment is being studied. Recent activities in the ORNL Aerosol Release and Transport Project include studies of (1) the thermal hydraulic conditions existing during Nuclear Safety Pilot Plant (NSPP) aerosol tests in steam-air environments, (2) the thermal output and aerosol mass generation rates for plasma torch aerosol generators, and (3) the influence of humidity on the shape of agglomerated aerosols of various materials. A new Aerosol-Moisture Interaction Test (AMIT) facility was prepared at the NSPP site to accommodate the aerosol shape studies; several tests with Fe/sub 2/O/sub 3/ aerosol have been conducted. In addition to the above activities a special study was conducted to determine the suitability of the technique of aerosol production by plasma torch under the operating conditions of future tests of the LWR Aerosol Containment Experiments (LACE) at the Hanford Engineering Development Laboratory. 3 refs., 2 figs., 7 tabs.

  19. Change in atmospheric mineral aerosols in response to climate: Last glacial period, preindustrial, modern, and doubled carbon dioxide climates

    E-Print Network [OSTI]

    2006-01-01T23:59:59.000Z

    parameters on mineral aerosol mobilization, transport, andand L. Kiehl (2003), Mineral aerosol and cloud interactions,for paleoclimate, in Dust Aerosols, Loess Soils and Global

  20. Direct measurements of marine aerosols to examine the influence of biological activity, anthropogenic emissions, and secondary processing on particle chemistry

    E-Print Network [OSTI]

    Gaston, Cassandra Jayne

    2012-01-01T23:59:59.000Z

    for fog processing of individual aerosol particles, Atmos.of marine secondary organic aerosol from biogenic amines,Pacific and their impacts on aerosol hygroscopicity in the

  1. Real-time characterization of particle-bound polycyclic aromatic hydrocarbons in ambient aerosols and from motor-vehicle exhaust

    E-Print Network [OSTI]

    Polidori, A.; Hu, S.; Biswas, S.; Delfino, R. J; Sioutas, C.

    2008-01-01T23:59:59.000Z

    between in-situ, real-time aerosol photoemis- sion intensityconcentration in combustion aerosols, Water, Air, Soilin-use commercial aircraft, Aerosol Sci. Tech. , 39(8), 799–

  2. Examination of the Effects of Sea Salt Aerosols on Southeast Texas Ozone and Secondary Organic Aerosol

    E-Print Network [OSTI]

    Benoit, Mark David

    2013-02-06T23:59:59.000Z

    condensation nuclei CPC Cloud condensation nuclei counter e-PTFE Expanded polytetrafluoroethylene HR-ToF-AMS High-resolution time-of-flight mass spectrometer HTDMA Humidified Tandem Differential Mobility Analyzer GHG Greenhouse Gas..., but their remains a gap in research of the aging process of sea salt aerosols, their impact on a polluted environment, and their role in heterogeneous reactions of gas phase species. The evolution of sea salt aerosols in the atmosphere results from interactions...

  3. A new aerosol collector for quasi on-line analysis of particulate organic matter: the Aerosol Collection Module (ACM) and first applications with a GC/MS-FID

    E-Print Network [OSTI]

    Hohaus, T.

    In many environments organic matter significantly contributes to the composition of atmospheric aerosol particles influencing its properties. Detailed chemical characterization of ambient aerosols is critical in order to ...

  4. Ultrasonic thickness testing of aging offshore structures

    E-Print Network [OSTI]

    Ellison, Brian Kirk

    1999-01-01T23:59:59.000Z

    . 14 2. 15 2. 16 2. 17 2. 18 New Anode. Spent Anode 1989 JIP Specimens. Dual Transducer Sound Paths. Specimens for Feasibility Studies (View I). Specimens for Feasibility Studies (View 2) . General Nomenclature. Transducer / Surface... study in an attempt to improve the effectiveness of ultrasonic thickness testing. Motivation for research stems from a joint industry project (JIP) that took place at Texas AIkM University (TAMU) from 1989 to 1990 (Moehlman 1990). In 1989, several...

  5. 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.

  6. 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.

  7. Calibration of the On-Line Aerosol Monitor (OLAM) with ammonium chloride and sodium chloride aerosols

    SciTech Connect (OSTI)

    Brockmann, J.E.; Lucero, D.A.; Romero, T. [Sandia National Labs., Albuquerque, NM (United States); Pentecost, G. [Idaho National Engineering Lab., Idaho Falls, ID (United States)

    1993-12-01T23:59:59.000Z

    The On-Line Aerosol Monitor (OLAM) is a light attenuation device designed and built at the Idaho National Engineering Laboratory (INEL) by EG&G Idaho. Its purpose is to provide an on-line indication of aerosol concentration in the PHEBUS-FP tests. It does this by measuring the attenuation of a light beam across a tube through which an aerosol is flowing. The OLAM does not inherently give an absolute response and must be calibrated. A calibration has been performed at Sandia National Laboratories` (SNL) Sandia Aerosol Research Laboratory (SARL) and the results are described here. Ammonium chloride and sodium chloride calibration aerosols are used for the calibration and the data for the sodium chloride aerosol is well described by a model presented in this report. Detectable instrument response is seen over a range of 0.1 cm{sup 3} of particulate material per m{sup 3} of gas to 10 cm{sup 3} of particulate material per m{sup 3} of gas.

  8. Secondary Ion Mass Spectrometry of Environmental Aerosols

    SciTech Connect (OSTI)

    Gaspar, Daniel J.; Cliff, John B.

    2010-08-01T23:59:59.000Z

    Atmospheric particles influence many aspects of climate, air quality and human health. Understanding the composition, chemistry and behavior of atmospheric aerosols is a key remaining challenge in improving climate models. Furthermore, particles may be traced back to a particular source based on composition, stable isotope ratios, or the presence of particular surface chemistries. Finally, the characterization of atmospheric particles in the workplace plays an important role in understanding the potential for exposure and environmental and human health effects to engineered and natural nanoscale particles. Secondary ion mass spectrometry (SIMS) is a useful tool in determining any of several aspects of the structure, composition and chemistry of these particles. Often used in conjunction with other surface analysis and electron microscopy methods, SIMS has been used to determine or confirm reactions on and in particles, the presence of particular organic species on the surface of atmospheric aerosols and several other interesting and relevant findings. Various versions of SIMS instruments – dynamic SIMS, time of flight secondary ion mass spectrometry or TOF-SIMS, nanoSIMS – have been used to determine specific aspects of aerosol structure and chemistry. This article describes the strengths of each type of SIMS instrument in the characterization of aerosols, along with guidance on sample preparation, specific characterization specific to the particular information sought in the analysis. Examples and guidance are given for each type of SIMS analysis.

  9. Group Report: Connections between Aerosol Properties

    E-Print Network [OSTI]

    Schwartz, Stephen E.

    14 Group Report: Connections between Aerosol Properties and Forcing of Climate S.E. XMWRZ, Rapporteur F.ARNOLD,J.-p.BLANCHET,PA. DURKEE, D.J.HOFMANN,W.A. HOPPEL, M.D. KING, A.A. LACE, T. NAKAJIMA

  10. Uncertainties and Frontiers in Aerosol Research

    E-Print Network [OSTI]

    ;Transport Power Industry Biomass burning Residential Human activity Perspective Aerosol Sources (rather than, Mixing, Chemistry, Climate) Climate Effects Resource: AeroCom, an international model intercomparison of fossil fuel (coal, oil, diesel, gasoline), domestic wood burning, forest fires #12;Natural sources

  11. 8, 32273285, 2008 Aerosol DRE in Po

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    in turn reducing cloud cover by heating the lower atmosphere (the semi-direct effect, Hansen et al., 1997 Chemistry and Physics Discussions Aerosol direct radiative effect in the Po Valley region derived from direct radiative effect (ADRE) affecting the Po Valley and the adjacent North Adriatic Sea is studied

  12. Group Report: Connections between Aerosol Properties

    E-Print Network [OSTI]

    increases absorption of solar radiation in clouds. The net effect is expected to be enhancement of shortwave effect and causes surface warming. Absorption of solar or thermal radiation within the atmospheric column after cloud evaporation. 3. Indirect effects ofaerosols on heterogeneous atmospheric chemistry. Aerosol

  13. Origin of atmospheric aerosols at the Pierre Auger Observatory using studies of air mass trajectories in South America

    E-Print Network [OSTI]

    Curci, Gabriele

    2014-01-01T23:59:59.000Z

    The Pierre Auger Observatory is making significant contributions towards understanding the nature and origin of ultra-high energy cosmic rays. One of its main challenges is the monitoring of the atmosphere, both in terms of its state variables and its optical properties. The aim of this work is to analyze aerosol optical depth $\\tau_{\\rm a}(z)$ values measured from 2004 to 2012 at the observatory, which is located in a remote and relatively unstudied area of the Pampa Amarilla, Argentina. The aerosol optical depth is in average quite low - annual mean $\\tau_{\\rm a}(3.5~{\\rm km})\\sim 0.04$ - and shows a seasonal trend with a winter minimum - $\\tau_{\\rm a}(3.5~{\\rm km})\\sim 0.03$ -, and a summer maximum - $\\tau_{\\rm a}(3.5~{\\rm km})\\sim 0.06$ -, and an unexpected increase from August to September - $\\tau_{\\rm a}(3.5~{\\rm km})\\sim 0.055$). We computed backward trajectories for the years 2005 to 2012 to interpret the air mass origin. Winter nights with low aerosol concentrations show air masses originating from t...

  14. Aerosolcloudprecipitation interactions. Part 1. The nature and sources of cloud-active aerosols

    E-Print Network [OSTI]

    Rutledge, Steven

    Aerosol­cloud­precipitation interactions. Part 1. The nature and sources of cloud-active aerosols M Available online 13 March 2008 Keywords: aerosol precipitation CCN emissions clouds Atmospheric aerosol the chemical composition of aerosols, their microphysical properties, and the factors that enable them to act

  15. Extraplanar Dust: a Tracer of Cold Dense Gas in the Thick Disks of Spiral Galaxies

    E-Print Network [OSTI]

    J. Christopher Howk

    2004-10-15T23:59:59.000Z

    The interstellar thick disks of galaxies contain not only gas, but significant quantities of dust. Most of our knowledge of extraplanar dust in disk galaxies comes from direct broadband optical imaging of these systems, wherein the dust is identified due to the irregular extinction it produces against the thick disk and bulge stars. This observational technique is sensitive to only the most dense material, and we argue much of the material identified in this way traces a cold phase of the interstellar thick disks in galaxies. The presence of a cold, dense phase likely implies the interstellar pressures in the thick disks of spiral galaxies can be quite high. This dense phase of the interstellar medium may also fueling thick disk star formation, and H-alpha observations are now revealing H II regions around newly-formed OB stars associations in several galaxies. We argue that the large quantities of dust and the morphologies of the structures traced by the dust imply that much of the extraplanar material in disk galaxies must have been expelled from the underlying thin disk.

  16. 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.

  17. Laboratory Experiments and Instrument Development for the Study of Atmospheric Aerosols

    SciTech Connect (OSTI)

    Davidovits, Paul

    2011-12-10T23:59:59.000Z

    Soot particles are generated by incomplete combustion of fossil and biomass fuels. Through direct effects clear air aerosols containing black carbon (BC) such as soot aerosols, absorb incoming light heating the atmosphere, while most other aerosols scatter light and produce cooling. Even though BC represents only 1-2% of the total annual emissions of particulate mass to the atmosphere, it has been estimated that the direct radiative effect of BC is the second-most important contributor to global warming after absorption by CO2. Ongoing studies continue to underscore the climate forcing importance of black carbon. However, estimates of the radiative effects of black carbon on climate remain highly uncertain due to the complexity of particles containing black carbon. Quantitative measurement of BC is challenging because BC often occurs in highly non-spherical soot particles of complex morphology. Freshly emitted soot particles are typically fractal hydrophobic aggregates. The aggregates consist of black carbon spherules with diameters typically in the range of about 15-40 nm, and they are usually coated by adsorbed polyaromatic hydrocarbons (PAHs) produced during combustion. Diesel-generated soot particles are often emitted with an organic coating composed primarily of lubricating oil and unburned fuel, as well as well as PAH compounds. Sulfuric acid has also been detected in diesel and aircraft-emitted soot particles. In the course of aging, these particle coatings may be substantially altered by chemical reactions and/or the deposition of other materials. Such processes transform the optical and CCN properties of the soot aerosols in ways that are not yet well understood. Our work over the past seven years consisted of laboratory research, instrument development and characterization, and field studies with the central focus of improving our understanding of the black carbon aerosol climate impacts. During the sixth year as well as during this seventh year (no-cost extension period) of our grant, we extended our studies to perform experiments on the controlled production and characterization of secondary organic aerosol.

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

    SciTech Connect (OSTI)

    Mazzoleni, Claudio [Michigan Technological University; Kumar, Sumit [Michigan Technological University; Wright, Kendra [Michigan Technological University; Kramer, Louisa [Michigan Technological University; Mazzoleni, Lynn [Michigan Technological University; Owen, Robert [Michigan Technological University; Helmig, Detlev [University of Colorado at Boulder

    2014-12-09T23:59:59.000Z

    The scientific scope of the project was to exploit the unique location of the Pico Mountain Observatory (PMO) located in the summit caldera of the Pico Volcano in Pico Island in the Azores, for atmospheric studies. The observatory, located at 2225m a.s.l., typically samples free tropospheric aerosols laying above the marine low-level clouds and long-range transported from North America. The broad purpose of this research was to provide the scientific community with a better understanding of fundamental physical processes governing the effects of aerosols on radiative forcing and climate; with the ultimate goal of improving our abilities to understand past climate and to predict future changes through numerical models. The project was 'exploratory' in nature, with the plan to demonstrate the feasibility of deploying for the first time, an extensive aerosol research package at PMO. One of the primary activities was to test the deployment of these instruments at the site, to collect data during the 2012 summer season, and to further develop the infrastructure and the knowledge for performing novel research at PMO in follow-up longer-term aerosol-cloud studies. In the future, PMO could provide an elevated research outpost to support the renewed DOE effort in the Azores that was intensified in 2013 with the opening of the new sea-level ARM-DOE Eastern North Atlantic permanent facility at Graciosa Island. During the project period, extensive new data sets were collected for the planned 2012 season. Thanks to other synergistic activities and opportunities, data collection was then successfully extended to 2013 and 2014. Highlights of the scientific findings during this project include: a) biomass burning contribute significantly to the aerosol loading in the North Atlantic free troposphere; however, long-range transported black carbon concentrations decreased substantially in the last decade. b) Single black carbon particles – analyzed off-line at the electron microscope – were often very compacted, suggesting cloud processing and exhibiting different optical properties from fresh emissions. In addition, black carbon was found to be sometimes mixed with mineral dust, affecting its optical properties and potential forcing. c) Some aerosols collected at PMO acted as ice nuclei, potentially contributing to cirrus cloud formation during their transport in the upper free troposphere. Identified good ice nuclei were often mineral dust particles. d) The free tropospheric aerosols studied at PMO have relevance to low level marine clouds due, for example, to synoptic subsidence entraining free tropospheric aerosols into the marine boundary layer. This has potentially large consequences on cloud condensation nuclei concentrations and compositions in the marine boundary layer; therefore, having an effect on the marine stratus clouds, with potentially important repercussions on the radiative forcing. The scientific products of this project currently include contributions to two papers published in the Nature Publishing group (Nature Communications and Scientific Reports), one paper under revision for Atmospheric Chemistry and Physics, one in review in Geophysical Research Letters and one recently submitted to Atmospheric Chemistry and Physics Discussion. In addition, four manuscripts are in advanced state of preparation. Finally, twenty-eight presentations were given at international conferences, workshops and seminars.

  19. Skin thickness effects on in vivo LXRF

    SciTech Connect (OSTI)

    Preiss, I.L.; Washington, W. II [Rensselaer Polytechnic Inst., Troy, NY (United States)

    1995-12-31T23:59:59.000Z

    The analysis of lead concentration in bone utilizing LXRF can be adversely effected by overlying issue. A quantitative measure of the attenuation of the 10.5 keV Pb L a x-ray signal by skin and skin equivalent plastic has been conducted. Concentration ranges in plaster of Paris and goat bone from 7 to 90 ppm with attenuators of Lucite{reg_sign} and pig skin were examined. It is concluded that no quantitative or semi quantitative analysis can be achieved if overlying sue thickness exceeds 3 mm for Ph concentrations of less than 30 porn Ph in bone.

  20. Intercomparison and Evaluation of Global Aerosol Microphysical Properties among AeroCom Models of a Range of Complexity

    SciTech Connect (OSTI)

    Mann, G. W.; Carslaw, K. S.; Reddington, C. L.; Pringle, K. J.; Schulz, M.; Asmi, A.; Spracklen, D. V.; Ridley, D. A.; Woodhouse, M. T.; Lee, L. A.; Zhang, Kai; Ghan, Steven J.; Easter, Richard C.; Liu, Xiaohong; Stier, P.; Lee, Y. H.; Adams, P. J.; Tost, H.; Lelieveld, J.; Bauer, S.; Tsigaridis, Kostas; van Noije, T.; Strunk, A.; Vignati, E.; Bellouin, N.; Dalvi, M.; Johnson, C. E.; Bergman, T.; Kokkola, H.; Von Salzen, Knut; Yu, Fangqun; Luo, Gan; Petzold, A.; Heintzenberg, J.; Clarke, A. D.; Ogren, J. A.; Gras, J.; Baltensperger, Urs; Kaminski, U.; Jennings, S. G.; O'Dowd, C. D.; Harrison, R. M.; Beddows, D. C.; Kulmala, M.; Viisanen, Y.; Ulevicius, V.; Mihalopoulos, Nikos; Zdimal, V.; Fiebig, M.; Hansson, H. C.; Swietlicki, E.; Henzing, J. S.

    2014-05-13T23:59:59.000Z

    Many of the next generation of global climate models will include aerosol schemes which explicitly simulate the microphysical processes that determine the particle size distribution. These models enable aerosol optical properties and cloud condensation nuclei (CCN) concentrations to be determined by fundamental aerosol processes, which should lead to a more physically based simulation of aerosol direct and indirect radiative forcings. This study examines the global variation in particle size distribution simulated by twelve global aerosol microphysics models to quantify model diversity and to identify any common biases against observations. Evaluation against size distribution measurements from a new European network of aerosol supersites shows that the mean model agrees quite well with the observations at many sites on the annual mean, but there are some seasonal biases common to many sites. In particular, at many of these European sites, the accumulation mode number concentration is biased low during winter and Aitken mode concentrations tend to be overestimated in winter and underestimated in summer. At high northern latitudes, the models strongly underpredict Aitken and accumulation particle concentrations compared to the measurements, consistent with previous studies that have highlighted the poor performance of global aerosol models in the Arctic. In the marine boundary layer, the models capture the observed meridional variation in the size distribution, which is dominated by the Aitken mode at high latitudes, with an increasing concentration of accumulation particles with decreasing latitude. Considering vertical profiles, the models reproduce the observed peak in total particle concentrations in the upper troposphere due to new particle formation, although modelled peak concentrations tend to be biased high over Europe. Overall, the results suggest that most global aerosol microphysics models simulate the global variation of the particle size distribution with a good degree of skill, but some models are in poor agreement with the observations. Further work is required to better constrain size-resolved primary and secondary particle number sources, and an improved understanding of nucleation and growth (e.g. the role of nitrate and secondary organics) will improve the fidelity of simulated particle size distributions.

  1. Real-time detection of ambient aerosols using photothermal interferometry: Folded Jamin interferometer

    E-Print Network [OSTI]

    Real-time detection of ambient aerosols using photothermal interferometry: Folded Jamin of instrumentation that can directly measure ambient aerosol absorption through photothermal interferometry. The hallmark of this approach is its ability to directly measure aerosol absorption without interference from

  2. The impact of meteorological conditions and variation in chemical composition of aerosols on regional cloud formation

    E-Print Network [OSTI]

    Creamean, Jessie Marie

    2012-01-01T23:59:59.000Z

    MISSION A Global 3D View of Aerosols and Clouds, Bulletin ofJ.H. Seinfeld, Secondary aerosol formation from atmosphericJ.H. Seinfeld, Secondary aerosol formation from atmospheric

  3. Local Environmental Pollution Strongly Influences Culturable Bacterial Aerosols at an Urban Aquatic Superfund Site

    E-Print Network [OSTI]

    Uriarte, Maria

    Local Environmental Pollution Strongly Influences Culturable Bacterial Aerosols at an Urban Aquatic Information ABSTRACT: In polluted environments, when microbial aerosols originate locally, species composition of the aerosols should reflect the polluted source. To test the connection between local environmental pollution

  4. FOSSIL ENERGY, CO2, CLIMATE CHANGE, AND THE AEROSOL PROBLEM Stephen E. Schwartz

    E-Print Network [OSTI]

    been masked by the aerosol cooling forcing. Allowable future CO2 emissions so as not to commit of the greenhouse gas forcing due to cooling forcing by tropospheric aerosols; as aerosols, unlike CO2, are short

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

    E-Print Network [OSTI]

    Lee, Keun-Hee

    2012-02-14T23:59:59.000Z

    precipitation even in the weakest hurricane. When comparing the model performance between aerosol indirect and direct effect by ensemble experiments, the adjustment time of the circulation due to modification of the aerosol radiative forcing by aerosol layers...

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

    E-Print Network [OSTI]

    Quaas, Johannes

    2010-01-01T23:59:59.000Z

    such as cloud contamination or 3D radiation effects (Loebeffect relationship behind the aerosol – cloud/radiationradiation resulting in the “aerosol direct effect”. Hy- drophilic aerosols can serve as cloud

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

    E-Print Network [OSTI]

    Quaas, Johannes

    2010-01-01T23:59:59.000Z

    such as cloud contamination or 3D radiation effects (Loebeffect relationship behind the aerosol – cloud/radiationradiation resulting in the “aerosol direct effect”. Hy- drophilic aerosols can serve as cloud

  8. Hybrid Optical Pumping of Optically Dense Alkali-Metal Vapor without Quenching Gas

    SciTech Connect (OSTI)

    Romalis, M. V. [Department of Physics, Princeton University, Princeton, New Jersey 08544 (United States)

    2010-12-10T23:59:59.000Z

    Optical pumping of an optically thick atomic vapor typically requires a quenching buffer gas, such as N{sub 2}, to prevent radiation trapping of unpolarized photons which would depolarize the atoms. We show that optical pumping of a trace contamination of Rb present in K metal results in a 4.5 times higher polarization of K than direct optical pumping of K in the absence of N{sub 2}. Such spin-exchange polarization transfer from optically thin species is useful in a variety of areas, including spin-polarized nuclear scattering targets and electron beams, quantum-nondemolition spin measurements, and ultrasensitive magnetometry.

  9. MELCOR aerosol transport module modification for NSSR-1

    SciTech Connect (OSTI)

    Merrill, B.J.; Hagrman, D.L.

    1996-03-01T23:59:59.000Z

    This report describes modifications of the MELCOR computer code aerosol transport module that will increase the accuracy of calculations for safety analysis of the International Thermonuclear Experimental Reactor (ITER). The modifications generalize aerosol deposition models to consider gases other than air, add specialized models for aerosol deposition during high speed gas flows in ducts, and add models for resuspension of aerosols that are entrained in coolants when these coolants flash. Particular attention has been paid to the adhesion of aerosol particles once they are transported to duct walls. The results of calculations with the modified models have been successfully compared to data from Light Water Reactor Aerosol Containment Experiments (LACE) conducted by an international consortium at Hanford, Washington.

  10. Climate Engineering with Stratospheric Aerosols and Associated Engineering Parameters

    SciTech Connect (OSTI)

    Kravitz, Benjamin S.

    2013-02-12T23:59:59.000Z

    Climate engineering with stratospheric aerosols, an idea inspired by large volcaniceruptions, could cool the Earth’s surface and thus alleviate some of the predicted dangerous impacts of anthropogenic climate change. However, the effectiveness of climate engineering to achieve a particular climate goal, and any associated side effects, depend on certain aerosol parameters and how the aerosols are deployed in the stratosphere. Through the examples of sulfate and black carbon aerosols, this paper examines "engineering" parameters-aerosol composition, aerosol size, and spatial and temporal variations in deployment-for stratospheric climate engineering. The effects of climate engineering are sensitive to these parameters, suggesting that a particle could be found ordesigned to achieve specific desired climate outcomes. This prospect opens the possibility for discussion of societal goals for climate engineering.

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

    SciTech Connect (OSTI)

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

    2009-09-25T23:59:59.000Z

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

  12. Light Trapping Textures Designed by Electromagnetic Optimization for Sub-Wavelength Thick Solar Cells

    E-Print Network [OSTI]

    Ganapati, Vidya; Yablonovitch, Eli

    2013-01-01T23:59:59.000Z

    Light trapping in solar cells allows for increased current and voltage, as well as reduced materials cost. It is known that in geometrical optics, a maximum 4n^2 absorption enhancement factor can be achieved by randomly texturing the surface of the solar cell, where n is the material refractive index. This ray-optics absorption enhancement limit only holds when the thickness of the solar cell is much greater than the optical wavelength. In sub-wavelength thin films, the fundamental questions remain unanswered: (1) what is the sub-wavelength absorption enhancement limit and (2) what surface texture realizes this optimal absorption enhancement? We turn to computational electromagnetic optimization in order to design nanoscale textures for light trapping in sub-wavelength thin films. For high-index thin films, in the weakly absorbing limit, our optimized surface textures yield an angle- and frequency-averaged enhancement factor ~39. They perform roughly 30% better than randomly textured structures, but they fall...

  13. Stackable differential mobility analyzer for aerosol measurement

    DOE Patents [OSTI]

    Cheng, Meng-Dawn (Oak Ridge, TN); Chen, Da-Ren (Creve Coeur, MO)

    2007-05-08T23:59:59.000Z

    A multi-stage differential mobility analyzer (MDMA) for aerosol measurements includes a first electrode or grid including at least one inlet or injection slit for receiving an aerosol including charged particles for analysis. A second electrode or grid is spaced apart from the first electrode. The second electrode has at least one sampling outlet disposed at a plurality different distances along its length. A volume between the first and the second electrode or grid between the inlet or injection slit and a distal one of the plurality of sampling outlets forms a classifying region, the first and second electrodes for charging to suitable potentials to create an electric field within the classifying region. At least one inlet or injection slit in the second electrode receives a sheath gas flow into an upstream end of the classifying region, wherein each sampling outlet functions as an independent DMA stage and classifies different size ranges of charged particles based on electric mobility simultaneously.

  14. 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.

  15. aerosols influencing atmospheric: Topics by E-print Network

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

    and other anthropogenic influences have substantially altered the composition and size-distribution of atmospheric aerosol particles over the last century. This, in turn,...

  16. aerodyne aerosol mass: Topics by E-print Network

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

    independent measurements of fine particle volume or particle-into-liquid sampler (PILS) ion chromatography measurements for 3 field campaigns with different dominant aerosol...

  17. aerosol particle concentration: Topics by E-print Network

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

    the chemical and physical characterization of aerosols using a single particle mass spectrometry based technique University of California eScholarship Repository Summary: Real-...

  18. aerosol particle charger: Topics by E-print Network

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

    Introduction The Universal Serial Bus (USB) port Allen, Jont 9 New approaches for the chemical and physical characterization of aerosols using a single particle mass spectrometry...

  19. aerosol mass spectrometer: Topics by E-print Network

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

    2004. The concentration of a species Zhang, Qi 8 Development of a thermal desorption chemical ionization mobility mass spectrometer for the speciation of ultrafine aerosols. Open...

  20. aerosol particles generated: Topics by E-print Network

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

    the chemical and physical characterization of aerosols using a single particle mass spectrometry based technique University of California eScholarship Repository Summary: Real-...

  1. 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...

  2. aerosol detection equipment: Topics by E-print Network

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

    Daniel, Rosenfeld 464 Mixtures of pollution, dust, sea salt, and volcanic aerosol during ACE-Asia: Radiative properties Energy Storage, Conversion and Utilization Websites...

  3. Atmospheric Aerosol Chemistry, Climate Change, and Air Quality

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

    aerosols, or OA, containing nitrogen- containing organic compounds (NOC) and only carbon, hydrogen, and oxygen (CHO). They uncovered a new method for investigating OA that may lead...

  4. The Time Evolution of Aerosol Size Distribution Over the Mexico...

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

    Size Distribution Over the Mexico City Plateau. The Time Evolution of Aerosol Size Distribution Over the Mexico City Plateau. Abstract: As part of the MILAGRO field campaign, the...

  5. aerosol mass spectrometry: Topics by E-print Network

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

    analysis of aerosol organic nitrates with electron ionization high-resolution mass spectrometry MIT - DSpace Summary: Four hydroxynitrates (R(OH)R'ONO2) representative of...

  6. aerosol assisted chemical: 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 5 Simulating Aerosols Using a Chemical Transport Model with Assimilation of...

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

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

    1. Introduction 2 Current models tend to under-predict secondary organic aerosol (SOA Weber, Rodney 3 Modeling particle formation during low-pressure silane oxidation: Detailed...

  8. 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...

  9. ambient fine 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 Chemical characterization of the ambient organic aerosol soluble in water:...

  10. aerosol chemical characteristion: 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 5 Simulating Aerosols Using a Chemical Transport Model with Assimilation of...

  11. aerosol characterization experiment: 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 8 Desert dust aerosol age characterized by massage tracking of tracers...

  12. aerosol generation characterization: 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 5 Desert dust aerosol age characterized by massage tracking of tracers...

  13. aerosol monitor development: Topics by E-print Network

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

    Paris May 2003John Matthews Monitoring the Aerosol Phase Function University of New Mexico 12;AstroParticles & Atmosphere, Paris May 2003John Matthews 12;AstroParticles &...

  14. aerosol characteristic researching: Topics by E-print Network

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

    as they have significant impacts both on localregional air pollution and global climate. Recent for Aerosol and Cloud Chemistry, Aerodyne Research, Incorporated, Billerica,...

  15. aerosol challenge model: Topics by E-print Network

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

    climate change is important because of its strong capability in causing extinction of solar radiation. A three-dimensional interactive aerosol-climate model has been used to...

  16. aircraft exhaust aerosol: Topics by E-print Network

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

    Window Location on a King Air 200 Aircraft:aerosol.atmos.und.edu) Objective A Raytheon Beechcraft King Air 200 aircraft has been used to obtain Condensation Particle...

  17. Behavior of aerosols in a steam-air environment

    SciTech Connect (OSTI)

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

    1985-01-01T23:59:59.000Z

    The behavior of aerosols assumed to be characteristic of those generated during light water reactor (LWR) accident sequences and released into containment is being studied in the Nuclear Safety Pilot Plant (NSPP) which is located at the Oak Ridge National Laboratory (ORNL). The program plan for the NSPP aerosol project provides for the study of the behavior, within containment, of simulated LWR accident aerosols emanating from fuel, reactor core structural materials, and from concrete-molten core materials interactions. The aerodynamic behavior of each of these aerosols was studied individually to establish its characteristics; current experiments involve mixtures of these aerosols to establish their interaction and collective behavior within containment. Tests have been conducted with U/sub 3/O/sub 8/ aerosols, Fe/sub 2/O/sub 3/ aerosols, and concrete aerosols in an environment of either dry air (relative humidity (RH) less than 20%) or steam-air (relative humidity (RH) approximately 100%) with aerosol mass concentration being the primary experimental variable.

  18. 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.

  19. LWR aerosol containment experiments (LACE) program and initial test results

    SciTech Connect (OSTI)

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

    1983-11-01T23:59:59.000Z

    Objectives of the test program are to demonstrate, at large-scale, inherent radioactive aerosol retention behavior for postulated high consequence LWR accident situations, and to provide a data base to be used for aerosol behavior and thermal hydraulic computer code validation. The LACE program is being performed in two phases. The first phase is scoping studies of aerosol retention for a containment by pass sequence (Event V). The second phase considers three accident situations where significant inherent aerosol retention could considerably reduce the calculated consequences of the postulated accidents.

  20. 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.

  1. Iron Speciation and Mixing in Single Aerosol Particles from the...

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

    iron from atmospheric aerosol is an essential nutrient that can control oceanic productivity, thereby impacting the global carbon budget and climate. Particles collected on...

  2. 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...

  3. aerosol main physical: Topics by E-print Network

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

    Mass light-scattering efficiencies were calculated from both an averaged aerosol size distribution and from distributions modified to reflect the effects of cloud. These...

  4. aerosols nanometriques application: Topics by E-print Network

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

    Mass light-scattering efficiencies were calculated from both an averaged aerosol size distribution and from distributions modified to reflect the effects of cloud. These...

  5. aerosols teresa application: Topics by E-print Network

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

    Mass light-scattering efficiencies were calculated from both an averaged aerosol size distribution and from distributions modified to reflect the effects of cloud. These...

  6. aerosol cfd model: Topics by E-print Network

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

    of aerosol dynamics in the atmosphere. The approach taken represents the particle size distribution as the superposition of three lognormal subdistributions, called modes....

  7. 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...

  8. aerosol bolus dispersion: Topics by E-print Network

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

    a significant scientific risk. Even the optimal altitude of injection and aerosol size distribution are poorly known. Past attention focused on guns and airplanes as means...

  9. aerosol particles originating: Topics by E-print Network

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

    of aerosol dynamics in the atmosphere. The approach taken represents the particle size distribution as the superposition of three lognormal subdistributions, called modes....

  10. 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...

  11. aerosol spray method: Topics by E-print Network

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

    Weber, Rodney 24 Use of in situ cloud condensation nuclei, extinction, and aerosol size distribution measurements to test a method for retrieving cloud Environmental...

  12. aerosol infection model: Topics by E-print Network

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

    of aerosol dynamics in the atmosphere. The approach taken represents the particle size distribution as the superposition of three lognormal subdistributions, called modes....

  13. atmospheric aerosol emissions: Topics by E-print Network

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

    gases, and sulfate aerosols are predicted to raise global temperatures via the "greenhouse effect" (IPCC, 1996), growing emissions of SO2Interactions Among Emissions, Atmospheric...

  14. atmospheric aerosols basic: Topics by E-print Network

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

    of atmospheric aerosol. Aplin, KL 2012-01-01 13 1. Introduction The atmospheric greenhouse effect is the basic mechanism Environmental Sciences and Ecology Websites Summary: 1....

  15. Aerosols, Clouds, and Climate Change Stephen E. Schwartz

    E-Print Network [OSTI]

    Schwartz, Stephen E.

    in atmospheric carbon dioxide associated with fossil fuel combustion. Briefly the options are mitigation work has shown instances of large magnitude of aerosol indirect forcing, with local instantaneous

  16. Atmospheric pressure flow reactor / aerosol mass spectrometer studies of tropospheric aerosol nucleat and growth kinetics. Final report, June, 2001

    SciTech Connect (OSTI)

    Worsnop, Douglas R.

    2001-06-01T23:59:59.000Z

    The objective of this program was to determine the mechanisms and rates of growth and transformation and growth processes that control secondary aerosol particles in both the clear and polluted troposphere. The experimental plan coupled an aerosol mass spectrometer (AMS) with a chemical ionization mass spectrometer to provide simultaneous measurement of condensed and particle phases. The first task investigated the kinetics of tropospheric particle growth and transformation by measuring vapor accretion to particles (uptake coefficients, including mass accommodation coefficients and heterogeneous reaction rate coefficients). Other work initiated investigation of aerosol nucleation processes by monitoring the appearance of submicron particles with the AMS as a function of precursor gas concentrations. Three projects were investigated during the program: (1) Ozonolysis of oleic acid aerosols as model of chemical reactivity of secondary organic aerosol; (2) Activation of soot particles by measurement deliquescence in the presence of sulfuric acid and water vapor; (3) Controlled nucleation and growth of sulfuric acid aerosols.

  17. Mapping crustal thickness using marine gravity data: Methods and uncertainties

    E-Print Network [OSTI]

    Müller, Dietmar

    of petroleum systems within passive margins. However, direct measurements of crustal thickness are sparse geophysical data, to estimate crustal thickness. We evaluated alternative gravity inversion methodol- ogies, but economic considerations make gravity modeling a more practical approach for mapping crustal thickness over

  18. SciTech Connect: Results and code predictions for ABCOVE aerosol...

    Office of Scientific and Technical Information (OSTI)

    Results and code predictions for ABCOVE aerosol code validation - Test AB5 Citation Details In-Document Search Title: Results and code predictions for ABCOVE aerosol code...

  19. E-Print Network 3.0 - aerosol load study Sample Search Results

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

    conditions... reserved. Keywords: India; Aerosol loading; Aerosol forcing; MODIS; TOMS; Remote sensing 1. Introduction... heating effect on the earth surface and in turn...

  20. E-Print Network 3.0 - aerosol robotic network Sample Search Results

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

    ), AERONET--A federated instrument network and data archive for aerosol characterization, Remote Sens... Period examining aerosol properties and radiative ... Source: Brookhaven...

  1. aerosol source-receptor relationships: 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. Characterization of ambient aerosol composition and formation mechanisms and development of quantification methodologies utilizing ATOFMS

    E-Print Network [OSTI]

    Qin, Xueying

    2007-01-01T23:59:59.000Z

    cloud coverage as a consequence of aerosol heating effect after absorbing solar radiation.effects of aerosols can cause cooling since clouds reflect the incoming solar radiation

  3. Clustering of Aerosols in Atmospheric Turbulent Flow

    E-Print Network [OSTI]

    T. Elperin; N. Kleeorin; M. A. Liberman; V. L'vov; I. Rogachevskii

    2007-02-15T23:59:59.000Z

    A mechanism of formation of small-scale inhomogeneities in spatial distributions of aerosols and droplets associated with clustering instability in the atmospheric turbulent flow is discussed. The particle clustering is a consequence of a spontaneous breakdown of their homogeneous space distribution due to the clustering instability, and is caused by a combined effect of the particle inertia and a finite correlation time of the turbulent velocity field. In this paper a theoretical approach proposed in Phys. Rev. E 66, 036302 (2002) is further developed and applied to investigate the mechanisms of formation of small-scale aerosol inhomogeneities in the atmospheric turbulent flow. The theory of the particle clustering instability is extended to the case when the particle Stokes time is larger than the Kolmogorov time scale, but is much smaller than the correlation time at the integral scale of turbulence. We determined the criterion of the clustering instability for the Stokes number larger than 1. We discussed applications of the analyzed effects to the dynamics of aerosols and droplets in the atmospheric turbulent flow.

  4. TROPOSPHERIC AEROSOL PROGRAM, PROGRAM PLAN, MARCH 2001

    SciTech Connect (OSTI)

    SCHWARTZ,S.E.; LUNN,P.

    2001-03-01T23:59:59.000Z

    The goal of Tropospheric Aerosol Program (TAP) will be to develop the fundamental scientific understanding required to construct tools for simulating the life cycle of tropospheric aerosols--the processes controlling their mass loading, composition, and microphysical properties, all as a function of time, location, and altitude. The TAP approach to achieving this goal will be by conducting closely linked field, modeling, laboratory, and theoretical studies focused on the processes controlling formation, growth, transport, and deposition of tropospheric aerosols. This understanding will be represented in models suitable for describing these processes on a variety of geographical scales; evaluation of these models will be a key component of TAP field activities. In carrying out these tasks TAP will work closely with other programs in DOE and in other Federal and state agencies, and with the private sector. A forum to directly work with our counterparts in industry to ensure that the results of this research are translated into products that are useful to that community will be provided by NARSTO (formerly the North American Research Strategy on Tropospheric Ozone), a public/private partnership, whose membership spans government, the utilities, industry, and university researchers in Mexico, the US, and Canada.

  5. Radioactive waste disposal in thick unsaturated zones

    SciTech Connect (OSTI)

    Winograd, I.J.

    1981-06-26T23:59:59.000Z

    Portions of the Great Basin are undergoing crustal extension and have unsaturated zones as much as 600 meters thick. These areas contain multiple natural barriers capable of isolating solidified toxic wastes from the biosphere for tens of thousands to perhaps hundreds of thousands of years. An example of the potential utilization of such arid zone environments for toxic waste isolation is the burial of transuranic radioactive wastes at relatively shallow depths (15 to 100 meters) in Sedan Crater, Yucca Flat, Nevada. The volume of this man-made crater is several times that of the projected volume of such wastes to the year 2000. Disposal in Sedan Crater could be accomplished at a savings on the order of $0.5 billion, in comparison with current schemes for burial of such wastes in mined repositories at depths of 600 to 900 meters, and with an apparently equal likelihood of waste isolation from the biosphere. 4 figures.

  6. Investigation of Thin Cirrus Cloud Optical and Microphysical Properties on the Basis of Satellite Observations and Fast Radiative Transfer Models

    E-Print Network [OSTI]

    Wang, Chenxi

    2013-07-25T23:59:59.000Z

    This dissertation focuses on the global investigation of optically thin cirrus cloud optical thickness (tau) and microphysical properties, such as, effective particle size (D_(eff)) and ice crystal habits (shapes), based on the global satellite...

  7. Electro-optic device with gap-coupled electrode

    DOE Patents [OSTI]

    Deri, Robert J.; Rhodes, Mark A.; Bayramian, Andrew J.; Caird, John A.; Henesian, Mark A.; Ebbers, Christopher A.

    2013-08-20T23:59:59.000Z

    An electro-optic device includes an electro-optic crystal having a predetermined thickness, a first face and a second face. The electro-optic device also includes a first electrode substrate disposed opposing the first face. The first electrode substrate includes a first substrate material having a first thickness and a first electrode coating coupled to the first substrate material. The electro-optic device further includes a second electrode substrate disposed opposing the second face. The second electrode substrate includes a second substrate material having a second thickness and a second electrode coating coupled to the second substrate material. The electro-optic device additionally includes a voltage source electrically coupled to the first electrode coating and the second electrode coating.

  8. Ultrasonic thickness measuring and imaging system and method

    DOE Patents [OSTI]

    Bylenok, Paul J.; Patmos, William M.; Wagner, Thomas A.; Martin, Francis H.

    1992-08-04T23:59:59.000Z

    An ultrasonic thickness measuring and imaging system uses an ultrasonic fsed beam probe for measuring thickness of an object, such as a wall of a tube, a computer for controlling movement of the probe in a scanning pattern within the tube and processing an analog signal produced by the probe which is proportional to the tube wall thickness in the scanning pattern, and a line scan recorder for producing a record of the tube wall thicknesses measured by the probe in the scanning pattern. The probe is moved in the scanning pattern to sequentially scan circumferentially the interior tube wall at spaced apart adjacent axial locations. The computer processes the analog signal by converting it to a digital signal and then quantifies the digital signal into a multiplicity of thickness points with each falling in one of a plurality of thickness ranges corresponding to one of a plurality of shades of grey. From the multiplicity of quantified thickness points, a line scan recorder connected to the computer generates a pictorial map of tube wall thicknesses with each quantified thickness point thus being obtained from a minute area, e.g. 0.010 inch by 0.010 inch, of tube wall and representing one pixel of the pictorial map. In the pictorial map of tube wall thicknesses, the pixels represent different wall thicknesses having different shades of grey.

  9. Ultrasonic thickness measuring and imaging system and method

    DOE Patents [OSTI]

    Bylenok, Paul J. (Clifton Park, NY); Patmos, William M. (Schenectady, NY); Wagner, Thomas A. (Bronswick, NY); Martin, Francis H. (Melrose, NY)

    1992-01-01T23:59:59.000Z

    An ultrasonic thickness measuring and imaging system uses an ultrasonic fsed beam probe for measuring thickness of an object, such as a wall of a tube, a computer for controlling movement of the probe in a scanning pattern within the tube and processing an analog signal produced by the probe which is proportional to the tube wall thickness in the scanning pattern, and a line scan recorder for producing a record of the tube wall thicknesses measured by the probe in the scanning pattern. The probe is moved in the scanning pattern to sequentially scan circumferentially the interior tube wall at spaced apart adjacent axial locations. The computer processes the analog signal by converting it to a digital signal and then quantifies the digital signal into a multiplicity of thickness points with each falling in one of a plurality of thickness ranges corresponding to one of a plurality of shades of grey. From the multiplicity of quantified thickness points, a line scan recorder connected to the computer generates a pictorial map of tube wall thicknesses with each quantified thickness point thus being obtained from a minute area, e.g. 0.010 inch by 0.010 inch, of tube wall and representing one pixel of the pictorial map. In the pictorial map of tube wall thicknesses, the pixels represent different wall thicknesses having different shades of grey.

  10. A Generic Model for the Resuspension of Multilayer Aerosol Deposits by Turbulent Flow

    SciTech Connect (OSTI)

    Friess, H.; Yadigaroglu, G. [Swiss Federal Institute of Technology (Switzerland)

    2001-06-15T23:59:59.000Z

    An idealized lattice structure is considered of multilayer aerosol deposits, where every particle at the deposit surface is associated with a resuspension rate constant depending on a statistically distributed particle parameter and on flow conditions. The response of this generic model is represented by a set of integrodifferential equations. As a first application of the general formalism, the behavior of Fromentin's multilayer model is analyzed, and the model parameters are adapted to experimental data. In addition, improved relations between model parameters and physical input parameters are proposed. As a second application, a method is proposed for building multilayer models by using resuspension rate constants of existing monolayer models. The method is illustrated by a sample of monolayer data resulting from the model of Reeks, Reed, and Hall. Also discussed is the error to be expected if a monolayer resuspension model, which works well for thin aerosol deposits, is applied to thick deposits under the classical monolayer assumption that all deposited particles interact with the fluid at all times.

  11. aerosol ratio test: Topics by E-print Network

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

    aerosol ratio test 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 23 24 25 Next Page Last Page Topic Index 1 Effect of mineral dust aerosol...

  12. Organic Aerosol Formation Downwind from the Deepwater Horizon Oil Spill

    E-Print Network [OSTI]

    Toohey, Darin W.

    Organic Aerosol Formation Downwind from the Deepwater Horizon Oil Spill Nicole ONeill - ATOC 3500 and aerosol composition of air over the Deepwater Horizon oil spill in the Gulf of Mexico. · The lightest chemicals in the oil evaporated within hours, as scientists expected them to do. What they didn't expect

  13. Research Unit on Biosphere -Aerosol -Cloud -Climate Interactions

    E-Print Network [OSTI]

    the emissions of monoterpenes and the oxidation and gas-particle partitioning of their products. Here we into the aerosol phase. · Concentrations of individual products which partition between the gas and aerosol phases-limonene which is emitted in large quantities from a range of vegetation types e.g. d-limonene is the major

  14. The effect of roughness on aerosol deposition in tubes

    E-Print Network [OSTI]

    Chavez, Mario Cesar

    1997-01-01T23:59:59.000Z

    Experimental measurements of simulated roughness within tubes and the subsequent aerosol penetration performance through these tubes were conducted for a aerosol particle size range of 5 nm to 20 nm and a flow rate range of 28 L/min to 169.9 L...

  15. Effects of operating conditions on a heat transfer fluid aerosol

    E-Print Network [OSTI]

    Sukmarg, Passaporn

    2000-01-01T23:59:59.000Z

    fluids are used as hot liquids at elevated pressures. If loss of containment does occur, the liquid will leak under pressure and may disperse as a fine aerosol mist. Though it has been recognized that aerosol mists can explode, very little is known about...

  16. Carbonaceous aerosol particles from common vegetation in the Grand Canyon

    SciTech Connect (OSTI)

    Hallock, K.A.; Mazurek, M.A. (Brookhaven National Lab., Upton, NY (United States)); Cass, G.R. (California Inst. of Tech., Pasadena, CA (United States). Dept. of Environmental Engineering Science)

    1992-05-01T23:59:59.000Z

    The problem of visibility reduction in the Grand Canyon due to fine organic aerosol particles in the atmosphere has become an area of increased environmental concern. Aerosol particles can be derived from many emission sources. In this report, we focus on identifying organic aerosols derived from common vegetation in the Grand Canyon. These aerosols are expected to be significant contributors to the total atmospheric organic aerosol content. Aerosol samples from living vegetation were collected by resuspension of surface wax and resin components liberated from the leaves of vegetation common to areas of the Grand Canyon. The samples were analyzed using high-resolution gas chromatography/mass spectrometry (GC/MS). Probable identification of compounds was made by comparison of sample spectra with National Institute of Standards and Technology (NIST) mass spectral references and positive identification of compounds was made when possible by comparison with authentic standards as well as NIST references. Using these references, we have been able to positively identify the presence of n-alkane and n-alkanoic acid homolog series in the surface waxes of the vegetation sampled. Several monoterpenes, sesquiterpenes, and diterpenes were identified also as possible biogenic aerosols which may contribute to the total organic aerosol abundance leading to visibility reduction in the Grand Canyon.

  17. 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

  18. CLOUD PHYSICS From aerosol-limited to invigoration

    E-Print Network [OSTI]

    Napp, Nils

    CLOUD PHYSICS From aerosol-limited to invigoration of warm convective clouds Ilan Koren,1 * Guy Dagan,1 Orit Altaratz1 Among all cloud-aerosol interactions, the invigoration effect is the most elusive. Most of the studies that do suggest this effect link it to deep convective clouds with a warm base

  19. Absorption cross-section 139 Accumulation mode, of aerosol 146

    E-Print Network [OSTI]

    Jacob, Daniel J.

    133, 151 residence times 153 size distributions 144 Air composition 2 molecular weight 4, 6 Albedo 122 dioxide Coagulation (aerosol) 146 Column model 32 Conditional unstability 56 Continuity equation 75261 INDEX A Absorption cross-section 139 Accumulation mode, of aerosol 146 Acetaldehyde (CH3CHO

  20. Laboratory Measurements of Sea Salt Aerosol Refractive Index

    E-Print Network [OSTI]

    Oxford, University of

    . . . . . . . . . . . . . . . . . . . . . . 6 1.2.3 Complex Refractive Index . . . . . . . . . . . . . . . . . . . . 6 1.2.4 Size Distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 1.3.5 Coagulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 1.4 Sea Salt AerosolsLaboratory Measurements of Sea Salt Aerosol Refractive Index Thesis submitted for the degree

  1. AT631, Spring 2011 Introduction to Atmospheric Aerosols

    E-Print Network [OSTI]

    species partitioning between gas/aerosol phases 30 R LAB 10: Cloud condensation nuclei measurements April and their relationship to visibility and climate; · aerosol hygroscopicity and relationship to cloud formation; · gas of pertinent data and analysis and interpretation of these data. Each student will be asked to complete

  2. Cloud Condensation Nuclei (CCN) Analysis of Biogenic Secondary Organic Aerosol

    E-Print Network [OSTI]

    Collins, Gary S.

    Cloud Condensation Nuclei (CCN) Analysis of Biogenic Secondary Organic Aerosol Rachel L. Atlas1' gas-phase emissions and the aerosols they form (figure 6), including a cloud condensation nuclei Cloud condensation nuclei (CCN) are particles which water vapor condenses onto to form cloud droplets

  3. CLOUD DROPLET NUCLEATION AND ITS CONNECTION TO AEROSOL PROPERTIES

    E-Print Network [OSTI]

    of the uncertainty of the indirect effect arises from incomplete ability to describe changes in cloud properties. Keywords - Climate. aerosols. clouds, radiation INTRODUcnON In recent years awareness has increased of enhancement of scanering of radiation by aerosols in clear (cloud-free) air; a portion of the scattered

  4. Aerosol Science and Technology, 47:818830, 2013 Copyright C American Association for Aerosol Research

    E-Print Network [OSTI]

    chemical components are affected by in-canopy chemistry, vertical gradients in gas-particle Received 17 secondary organic aerosol (SOA) emitted. During BEARPEX-07, rapid in- canopy oxidation caused rapid SOA, and thermal shifts in gas-particle partitioning. Wet deposition was estimated to be an order of magnitude

  5. Cloud cover increase with increasing aerosol absorptivity: A counterexample to the conventional semidirect aerosol effect

    E-Print Network [OSTI]

    humidity. The net effect is more low cloud cover with increasing aerosol absorption. The higher specific by dust radiative heating. Although in some areas our model exhibits a reduction of low cloud cover due are expected to have a similar effect. Citation: Perlwitz, J., and R. L. Miller (2010), Cloud cover increase

  6. Transport of anthropogenic and biomass burning aerosols from Europe to the Arctic during spring 2008

    SciTech Connect (OSTI)

    Marelle, L.; Raut, Jean-Christophe; Thomas, J. L.; Law, K. S.; Quennehen, Boris; Ancellet, G.; Pelon, J.; Schwarzenboeck, A.; Fast, Jerome D.

    2015-01-01T23:59:59.000Z

    During the POLARCAT-France airborne campaign in April 2008, pollution originating from anthropogenic and biomass burning emissions was measured in the European Arctic. We compare these aircraft measurements with simulations using the WRF-Chem model to investigate model representation of aerosols transported from Europe to the Arctic. Modeled PM2.5 is evaluated using EMEP measurements in source regions and POLARCAT aircraft measurements in the Scandinavian Arctic, showing a good agreement, although the model overestimates nitrate and underestimates organic carbon in source regions. Using WRF-Chem in combination with the Lagrangian model FLEXPART-WRF, we find that during the campaign the research aircraft sampled two different types of European plumes: mixed anthropogenic and fire plumes from eastern Europe and Russia transported below 2 km, and anthropogenic plumes from central Europe uplifted by warm conveyor belt circulations to 5–6 km. Both modeled plume types had significant wet scavenging (> 50% PM10) during transport. Modeled aerosol vertical distributions and optical properties below the aircraft are evaluated in the Arctic using airborne LIDAR measurements. Evaluating the regional impacts in the Arctic of this event in terms of aerosol vertical structure, we find that during the 4 day presence of these aerosols in the lower European Arctic (< 75° N), biomass burning emissions have the strongest influence on concentrations between 2.5 and 3 km altitudes, while European anthropogenic emissions influence aerosols at both lower (~1.5 km) and higher altitudes (~4.5 km). As a proportion of PM2.5, modeled black carbon and SO4= concentrations are more enhanced near the surface. The European plumes sampled during POLARCAT-France were transported over the region of springtime snow cover in Northern Scandinavia, where they had a significant local atmospheric warming effect. We find that, during this transport event, the average modeled top of atmosphere (TOA) shortwave direct and semi-direct radiative effect (DSRE) north of 60° N over snow and ice-covered surfaces reaches +0.58 W m?², peaking at +3.3 W m?² at noon over Scandinavia and Finland.

  7. Experiments related to the resuspension of aerosols during hydrogen burns

    SciTech Connect (OSTI)

    Nelson, L.S.; Guay, K.P.

    1987-01-01T23:59:59.000Z

    We have performed seven ''add-on'' experiments in two large combustion facilities to investigate the capability of hydrogen burns to remove simulated structural and fission product aerosols previously deposited on small metal discs that have surfaces prototypical of those found in nuclear reactor containments. Our results suggest that hydrogen combustion provides an especially effective mechanism for removal (and, presumably, resuspension) of sedimented aerosols produced in a hypothetical nuclear reactor core-degradation or core-melting accident. The presence of condensing steam does not seem to assure adhesion of sedimented aerosols during hydrogen burns. Differences are exhibited between different surfaces as well as between types of aerosol. In-depth studies will be required to assess the impact exposure of sedimented aerosols to hydrogen burns might have on the radiological source term.

  8. Cladding Attachment Over Thick Exterior Insulating Sheathing

    SciTech Connect (OSTI)

    Baker, P.; Eng, P.; Lepage, R.

    2014-01-01T23:59:59.000Z

    The addition of insulation to the exterior of buildings is an effective means of increasing the thermal resistance of both wood framed walls as well as mass masonry wall assemblies. For thick layers of exterior insulation (levels greater than 1.5 inches), the use of wood furring strips attached through the insulation back to the structure has been used by many contractors and designers as a means to provide a convenient cladding attachment location (Straube and Smegal 2009, Pettit 2009, Joyce 2009, Ueno 2010). The research presented in this report is intended to help develop a better understanding of the system mechanics involved and the potential for environmental exposure induced movement between the furring strip and the framing. BSC sought to address the following research questions: 1. What are the relative roles of the mechanisms and the magnitudes of the force that influence the vertical displacement resistance of the system? 2. Can the capacity at a specified deflection be reliably calculated using mechanics based equations? 3. What are the impacts of environmental exposure on the vertical displacement of furring strips attached directly through insulation back to a wood structure?

  9. Optical keyboard

    DOE Patents [OSTI]

    Veligdan, James T. (Manorville, NY); Feichtner, John D. (Fiddletown, CA); Phillips, Thomas E. (San Diego, CA)

    2001-01-01T23:59:59.000Z

    An optical keyboard includes an optical panel having optical waveguides stacked together. First ends of the waveguides define an inlet face, and opposite ends thereof define a screen. A projector transmits a light beam outbound through the waveguides for display on the screen as a keyboard image. A light sensor is optically aligned with the inlet face for sensing an inbound light beam channeled through the waveguides from the screen upon covering one key of the keyboard image.

  10. 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.

  11. Method of dispersing particulate aerosol tracer

    DOE Patents [OSTI]

    O'Holleran, Thomas P. (Belleville, MI)

    1988-01-01T23:59:59.000Z

    A particulate aerosol tracer which comprises a particulate carrier of sheet silicate composition having a particle size up to one micron, and a cationic dopant chemically absorbed in solid solution in the carrier. The carrier is preferably selected from the group consisting of natural mineral clays such as bentonite, and the dopant is selected from the group consisting of rare earth elements and transition elements. The tracers are dispersed by forming an aqueous salt solution with the dopant present as cations, dispersing the carriers in the solution, and then atomizing the solution under heat sufficient to superheat the solution droplets at a level sufficient to prevent reagglomeration of the carrier particles.

  12. Study of Aerosol Indirect Effects in China

    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'sis Taking Over Our InstagramStructure of All-Polymer. . ~0s ALAMOS SCIENTIFIC LABORATORY ofAerosol

  13. 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

  14. 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.

  15. Evaluation of thickness and strain of thin planar layers of InAs on GaAs(001) using spectroscopic ellipsometry

    SciTech Connect (OSTI)

    Eyink, K. G.; Szmulowicz, F.; Esposito, D.; Grazulis, L.; Hill, M.; Mahalingam, K.; Aronow, A. J. [Nano Electronic Materials Branch (RXAN), Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433-7707 (United States)

    2014-07-21T23:59:59.000Z

    We develop a technique for accurately measuring thickness of planar InAs films grown on (001) GaAs by spectroscopic ellipsometry, using bulk optical constants. We observe that the critical point structure for the E{sub 1} and E{sub 1}?+??{sub 1} transitions extracted from the measured dielectric properties varies with strain in the layer. Transmission electron microscopy confirms the extracted thickness and measures the residual strain based on the dislocation spacing in the film. At small thickness, the E{sub 1} critical point is seen to markedly deviate from the dependence predicted by deformation potential theory and appears to be consistent with additional quantum confinement effects.

  16. Turbulent diffusion and turbulent thermal diffusion of aerosols in stratified atmospheric flows

    E-Print Network [OSTI]

    Elperin, Tov

    Turbulent diffusion and turbulent thermal diffusion of aerosols in stratified atmospheric flows M to the turbulent diffusion, and its potential impact on aerosol distribution. This phenomenon was predicted a nondiffusive flux of aerosols in the direction of the heat flux and results in formation of long-living aerosol

  17. Sensitivity study of the residue method for the detection of aerosols from space-borne sensors

    E-Print Network [OSTI]

    Stoffelen, Ad

    Sensitivity study of the residue method for the detection of aerosols from space-borne sensors Martin de Graaf April 2002 #12;Sensitivity study of the residue method for the detection of aerosols from of aerosol parameters on residue 3 2.1 Standard aerosol and atmosphere parameters

  18. 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

  19. 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

  20. Assessment of the Upper Particle Size Limit for Quantitative Analysis of Aerosols Using

    E-Print Network [OSTI]

    Hahn, David W.

    the vaporization dynamics of individual aerosol particles, such as thermophoretic forces and vapor expulsion. Since