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1

A New Assessment of the Aerosol First Indirect Effect  

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

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

2

Parameterizations of Cloud Microphysics and Indirect Aerosol Effects  

SciTech Connect (OSTI)

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

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

2014-05-19T23:59:59.000Z

3

Observations of the first aerosol indirect effect in shallow cumuli  

SciTech Connect (OSTI)

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.

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

2011-02-08T23:59:59.000Z

4

Quantifying the Aerosol Indirect Effect Using Ground-Based Remote Sensors and Models  

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

Quantifying the Aerosol Indirect Effect Quantifying the Aerosol Indirect Effect Using Ground-Based Remote Sensors and Models G. Feingold National Oceanic and Atmospheric Administration Environmental Technology Laboratory Boulder, Colorado D. E. Lane Rutgers University Camden, New Jersey Q.-L. Min Atmospheric Sciences Research Center State University of New York Albany, New York Introduction The effect of aerosols on cloud microphysical and radiative properties (the "indirect effect") has the greatest uncertainty of all known climate-forcing mechanisms. Increases in aerosol concentrations result in higher concentrations of cloud condensation nuclei (CCN), increased cloud droplet concentrations, and smaller droplet sizes (Twomey 1974). A possible secondary effect is the suppression of rainfall.

5

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

SciTech Connect (OSTI)

The global and annual mean aerosol direct and indirect effects estimated from Community Earth System Model (CESM) simulations are -0.06 W m-2 and -1.39 W m-2, respectively.

Koch, D

2011-06-22T23:59:59.000Z

6

Analysis of Aerosol Indirect Effects in California Coastal Stratus and Fog  

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

Analysis of Aerosol Indirect Effects in California Coastal Stratus and Fog Analysis of Aerosol Indirect Effects in California Coastal Stratus and Fog Miller, Mark Brookhaven National Laboratory Kollias, Pavlos Brookhaven National Laboratory Bartholomew, Mary Jane Brookhaven National Laboratory Daum, Peter Brookhaven National Laboratory Dunn, Maureen Brookhaven National Laboratory Jensen, Michael Brookhaven National Laboratory Liu, Yangang Brookhaven National Laboratory Vogelmann, Andrew Brookhaven National Laboratory Andrews, Betsy NOAA/CMDL Ogren, John NOAA/CMDL Turner, David University of Wisconsin-Madison Category: Field Campaigns Impacts of aerosol indirect effects are considered too uncertain for inclusion in reports issued by the Intergovernmental Panel on Climate Change. A major reason for this uncertainty is an insufficient physical

7

Surface-Based Remote Sensing of the Aerosol Indirect Effect at Southern Great Plains  

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

Surface-Based Remote Sensing of the Surface-Based Remote Sensing of the Aerosol Indirect Effect at Southern Great Plains G. Feingold and W. L. Eberhard National Oceanic and Atmospheric Administration Environmental Technology Laboratory Boulder, Colorado D. E. Vernon and M. Previdi Rutgers University New Brunswick, New Jersey Abstract We have demonstrated first measurements of the aerosol indirect effect using ground-based remote sensors at the Southern Great Plains (SGP) site. The response of non-precipitating, ice-free clouds to changes in aerosol loading is quantified in terms of a relative change in cloud-drop effective radius (r e ) for a relative change in aerosol extinction under conditions of equivalent cloud liquid water path (LWP). This is done in a single column of air at a temporal resolution of 20 s (spatial resolution of ~100 m).

8

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

E-Print Network [OSTI]

reflectivities. #12;3 In recent years, simulations of the aerosol indirect effect in general circulation models in satellite imagery data. Images at 3.7 µm are used in a semi-automated procedure for identifying polluted concentrations of cloud condensation nuclei (CCN) and more cloud droplets. Because droplet formation is rapid

9

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

SciTech Connect (OSTI)

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.

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

10

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

SciTech Connect (OSTI)

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

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

2012-03-30T23:59:59.000Z

11

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

SciTech Connect (OSTI)

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

Phillips, Vaughan T. J.

2013-10-18T23:59:59.000Z

12

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

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

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

13

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.

14

Investigation of Aerosol Indirect Effects using a Cumulus Microphysics Parameterization in a Regional Climate Model  

SciTech Connect (OSTI)

A new Zhang and McFarlane (ZM) cumulus scheme includes a two-moment cloud microphysics parameterization for convective clouds. This allows aerosol effects to be investigated more comprehensively by linking aerosols with microphysical processes in both stratiform clouds that are explicitly resolved and convective clouds that are parameterized in climate models. This new scheme is implemented in the Weather Research and Forecasting (WRF) model, which is coupled with the physics and aerosol packages from the Community Atmospheric Model version 5 (CAM5). A test case of July 2008 during the East Asian summer monsoon is selected to evaluate the performance of the new ZM scheme and to investigate aerosol effects on monsoon precipitation. The precipitation and radiative fluxes simulated by the new ZM scheme show a better agreement with observations compared to simulations with the original ZM scheme that does not include convective cloud microphysics and aerosol convective cloud interactions. Detailed analysis suggests that an increase in detrained cloud water and ice mass by the new ZM scheme is responsible for this improvement. To investigate precipitation response to increased anthropogenic aerosols, a sensitivity experiment is performed that mimics a clean environment by reducing the primary aerosols and anthropogenic emissions to 30% of that used in the control simulation of a polluted environment. The simulated surface precipitation is reduced by 9.8% from clean to polluted environment and the reduction is less significant when microphysics processes are excluded from the cumulus clouds. Ensemble experiments with ten members under each condition (i.e., clean and polluted) indicate similar response of the monsoon precipitation to increasing aerosols.

Lim, Kyo-Sun; Fan, Jiwen; Leung, Lai-Yung R.; Ma, Po-Lun; Singh, Balwinder; Zhao, Chun; Zhang, Yang; Zhang, Guang; Song, Xiaoliang

2014-01-29T23:59:59.000Z

15

The Indirect and Semi-Direct Aerosol Campaign  

SciTech Connect (OSTI)

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

Ghan, Steve

2014-03-24T23:59:59.000Z

16

Toward a Minimal Representation of Aerosols in Climate Models: Comparative Decomposition of Aerosol Direct, Semidirect, and Indirect Radiative Forcing  

Science Journals Connector (OSTI)

The authors have decomposed the anthropogenic aerosol radiative forcing into direct contributions from each aerosol species to the planetary energy balance through absorption and scattering of solar radiation, indirect effects of anthropogenic ...

S. J. Ghan; X. Liu; R. C. Easter; R. Zaveri; P. J. Rasch; J.-H. Yoon; B. Eaton

2012-10-01T23:59:59.000Z

17

Indirect and Semi-Direct Aerosol Campaign  

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

Campaign Campaign For the month of April, researchers are descending on and above Barrow, Alaska, to obtain data from the atmosphere that will help them understand the impacts that aerosols have on Arctic clouds and climate. Scientists sponsored by the U.S. Department of Energy's Atmospheric Radiation Measurement (ARM) Climate Research Facility are using a heavily instrumented aircraft to collect data from the sky, while instruments based at surface sites in Barrow and Atqasuk, Alaska, are obtaining measurements from the ground. Information obtained during the Indirect and Semi-Direct Aerosol Campaign, or ISDAC, will help scientists analyze the role of aerosols in climate, and represents a key contribution to Arctic climate research during International Polar Year.

18

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

Science Journals Connector (OSTI)

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

James A. Coakley Jr.; Christopher D. Walsh

2002-02-01T23:59:59.000Z

19

Quantifying the Uncertainties of Aerosol Indirect Effects and Impacts on Decadal-Scale Climate Variability in NCAR CAM5 and CESM1  

SciTech Connect (OSTI)

The main goal of this project is to systematically quantify the major uncertainties of aerosol indirect effects due to the treatment of moist turbulent processes that drive aerosol activation, cloud macrophysics and microphysics in response to anthropogenic aerosol perturbations using the CAM5/CESM1. To achieve this goal, the P.I. hired a postdoctoral research scientist (Dr. Anna Fitch) who started her work from the Nov.1st.2012. In order to achieve the project goal, the first task that the Postdoc. and the P.I. did was to quantify the role of subgrid vertical velocity variance on the activation and nucleation of cloud liquid droplets and ice crystals and its impact on the aerosol indirect effect in CAM5. First, we analyzed various LES cases (from dry stable to cloud-topped PBL) to check whether this isotropic turbulence assumption used in CAM5 is really valid. It turned out that this isotropic turbulence assumption is not universally valid. Consequently, from the analysis of LES, we derived an empirical formulation relaxing the isotropic turbulence assumption used for the CAM5 aerosol activation and ice nucleation, and implemented the empirical formulation into CAM5/CESM1, and tested in the single-column and global simulation modes, and examined how it changed aerosol indirect effects in the CAM5/CESM1. These results were reported in the poster section in the 18th Annual CESM workshop held in Breckenridge, CO during Jun.17-20.2013. While we derived an empirical formulation from the analysis of couple of LES from the first task, the general applicability of that empirical formulation was questionable, because it was obtained from the limited number of LES simulations. The second task we did was to derive a more fundamental analytical formulation relating vertical velocity variance to TKE using other information starting from basic physical principles. This was a somewhat challenging subject, but if this could be done in a successful way, it could be directly implemented into the CAM5 as a practical parameterization, and substantially contributes to achieving the project goal. Through an intensive research for about one year, we found appropriate mathematical formulation and tried to implement it into the CAM5 PBL and activation routine as a practical parameterized numerical code. During these processes, however, the Postdoc applied for another position in Sweden, Europe, and accepted a job offer there, and left NCAR in August 2014. In Sweden, Dr. Anna Fitch is still working on this subject in a part time, planning to finalize the research and to write the paper in a near future.

Park, Sungsu

2014-12-12T23:59:59.000Z

20

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

SciTech Connect (OSTI)

This study implemented first, second and glaciations aerosol indirect effects (AIE) on resolved clouds in the two-way coupled WRF-CMAQ modeling system by including parameterizations for both cloud drop and ice number concentrations on the basis of CMAQpredicted aerosol distributions and WRF meteorological conditions. The performance of the newly-developed WRF-CMAQ model, with alternate CAM and RRTMG radiation schemes, was evaluated with the observations from the CERES satellite and surface monitoring networks (AQS, IMPROVE, CASTNet, STN, and PRISM) over the continental U.S. (CONUS) (12-km resolution) and eastern Texas (4-km resolution) during August and September of 2006. The results at the AQS surface sites show that in August, the NMB values for PM2.5 over the eastern/western U.S (EUS/WUS) and western U.S. (WUS) are 5.3% (?0.1%) and 0.4% (-5.2%) for WRF-CMAQ/CAM (WRF-CMAQ/RRTMG), respectively. The evaluation of PM2.5 chemical composition reveals that in August, WRF-CMAQ/CAM (WRF-CMAQ/RRTMG) consistently underestimated the observed SO4 2? by -23.0% (-27.7%), -12.5% (-18.9%) and -7.9% (-14.8%) over the EUS at the CASTNet, IMPROVE and STN sites, respectively. Both models (WRF-CMAQ/CAM, WRF-CMAQ/RRTMG) overestimated the observed mean OC, EC and TC concentrations over the EUS in August at the IMPROVE sites. Both models generally underestimated the cloud field (SWCF) over the CONUS in August due to the fact that the AIE on the subgrid convective clouds was not considered when the model simulations were run at the 12 km resolution. This is in agreement with the fact that both models captured SWCF and LWCF very well for the 4-km simulation over the eastern Texas when all clouds were resolved by the finer domain. Both models generally overestimated the observed precipitation by more than 40% mainly because of significant overestimation in the southern part of the CONUS in August. The simulations of WRF-CMAQ/CAM and WRF-CMAQ/RRTMG show dramatic improvements for SWCF, LWCF, COD, cloud fractions and precipitation over the ocean relative to those of WRF default cases in August. The model performance in September is similar to that in August except for greater overestimation of PM2.5 due to the overestimations of SO4 2-, NH4 +, NO3 -, and TC over the EUS, less underestimation of clouds (SWCF) over the land areas due to about 10% lower SWCF values and less convective clouds in September.

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

2014-10-24T23:59:59.000Z

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


21

CARES: Carbonaceous Aerosol and Radiative Effects Study Science Plan  

SciTech Connect (OSTI)

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.

Zaveri, RA; Shaw, WJ; Cziczo, DJ

2010-05-27T23:59:59.000Z

22

Indirect radiative forcing by ion-mediated nucleation of aerosol  

SciTech Connect (OSTI)

A clear understanding of particle formation mechanisms is critical for assessing aerosol indirect radiative forcing and associated climate feedback processes. Recent studies reveal the importance of ion-mediated nucleation (IMN) in generating new particles and cloud condensation nuclei (CCN) in the atmosphere. Here we implement for the first time a physically based treatment of IMN into the Community Atmosphere Model version 5. Our simulations show that, compared to globally averaged results based on binary homogeneous nucleation (BHN), the presence of ionization (i.e., IMN) halves H2SO4 column burden, but increases the column integrated nucleation rate by around one order of magnitude, total particle number burden by a factor of ~ 3, CCN burden by ~ 10% (at 0.2% supersaturation) to 65% (at 1.0% supersaturation), and cloud droplet number burden by ~ 18%. Compared to BHN, IMN increases cloud liquid water path by 7.5%, decreases precipitation by 1.1%, and increases total cloud cover by 1.9%. This leads to an increase of total shortwave cloud radiative forcing by 3.67 W/m2 (more negative) and longwave cloud forcing by 1.78 W/m2 (more positive), resulting in a -1.9 W/m2 net change in cloud radiative forcing associated with IMN. The significant impacts of ionization on global aerosol formation, CCN abundance, and cloud radiative forcing may provide an important physical mechanism linking the global energy balance to various processes affecting atmospheric ionization, which should be properly represented in climate models.

Yu, Fangqun; Luo, Gan; Liu, Xiaohong; Easter, Richard C.; Ma, Xiaoyan; Ghan, Steven J.

2012-12-03T23:59:59.000Z

23

Constraining the influence of natural variability to improve estimates of global aerosol indirect effects in a nudged version of the Community Atmosphere Model 5  

E-Print Network [OSTI]

Zhao (2006), A simulated climatology of Asian dust aerosolN) PI (F) ? PI (F) ? X ? 2000 (PD Climatology) ? ? 2000 (PD Climatology) ? PD (F) X a All simulations used the same

Kooperman, Gabriel J; Pritchard, Michael S; Ghan, Steven J; Wang, Minghuai; Somerville, Richard C. J; Russell, Lynn M

2012-01-01T23:59:59.000Z

24

ARM - Field Campaign - Indirect and Semi-Direct Aerosol Campaign (ISDAC)  

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

govCampaignsIndirect and Semi-Direct Aerosol Campaign (ISDAC) govCampaignsIndirect and Semi-Direct Aerosol Campaign (ISDAC) Campaign Links ISDAC Website Related Campaigns Parameterization of Extinction Coefficient in Ice and Mixed-Phase Arctic Clouds During ISDAC 2010.10.01, Korolev, AAF ISDAC - Second Year Supplemental Surface Spectral Irradiance Measurements 2009.04.07, Lubin, NSA ISDAC - NASA ARCTAS Coordination with ARM 2008.04.01, Ferrare, NSA ISDAC / RISCAM - Humidified Tandem Differential Mobility Analyzer (HTDMA) 2008.04.01, Collins, NSA ISDAC - Hemispheric Flux Spectroradiometer 2008.03.31, Lubin, NSA Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Indirect and Semi-Direct Aerosol Campaign (ISDAC) 2008.04.01 - 2008.04.30 Website : http://acrf-campaign.arm.gov/isdac/

25

Indirect and Semi-Direct Aerosol Campaign: The Impact of Arctic...  

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

Aerosol Campaign: The Impact of Arctic Aerosols on Clouds . Abstract: A comprehensive dataset of microphysical and radiative properties of aerosols and clouds in the arctic...

26

Reflective Aerosols and the Greenhouse Effect  

Science Journals Connector (OSTI)

The contributions of atmospheric aerosols to add to either a climate-warming effect or climate-cooling effect depend on the chemical composition of the aerosol and the local environment. The best estimation is...

Kathryn E. Kautzman

2014-07-01T23:59:59.000Z

27

A numerical study of the effect of different aerosol types on East Asian summer clouds and precipitation  

SciTech Connect (OSTI)

The impact of anthropogenic aerosol on the East Asian summer monsoon (EASM) is investigated with NCAR CAM5, a state-of-the-art climate model with aerosols direct and indirect effects. Results indicate that anthropogenic aerosol tends to cause a weakened EASM with a southward shift of precipitation in East Asia mostly by its radiative effect. Anthropogenic aerosol induced surface cooling stabilizes the boundary layer, suppresses the convection and latent heat release in northern China, and reduces the tropospheric temperature over land and land-sea thermal contrast, thus leading to a weakened EASM. Meanwhile, acting as cloud condensation nuclei (CCN), anthropogenic aerosol can significantly increase the cloud droplet number concentration but decrease the cloud droplet effective radius over Indochina and Indian Peninsulas as well as over southwestern and northern China, inhibiting the precipitation in these regions. Thus, anthropogenic aerosol tends to reduce Southeast and South Asian summer monsoon precipitation by its indirect effect.

Jiang, Yiquan; Liu, Xiaohong; Yang, Xiuqun; Wang, Minghuai

2013-05-01T23:59:59.000Z

28

Effective Radius of Cloud Droplets by Ground-Based Remote Sensing: Relationships to Aerosol?  

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

Effective Radius of Cloud Droplets by Ground-Based Effective Radius of Cloud Droplets by Ground-Based Remote Sensing: Relationships to Aerosol? B.-G. Kim, S. E. Schwartz, and M. A. Miller Environmental Sciences Department Brookhaven National Laboratory Upton, New York Q.-L. Min Atmospheric Science Research Center State University of New York Albany, New York Introduction Aerosol Indirect Effect Increases in anthropogenic sources of cloud condensation nuclei can increase cloud albedo by increasing the concentration and reducing the size of cloud droplets, usually referred to as the indirect effect of aerosol on climate (Twomey 1977). However, the magnitudes of the various kinds of indirect forcing are particularly uncertain, because they involve subtle changes in cloud radiative properties and lifetimes

29

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

E-Print Network [OSTI]

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

Wood, Robert

30

ASIA-PACIFIC JOURNAL OF ATMOSPHERIC SCIENCES, 44, 1, 2008, p. 1-9 Ship tracks have been considered the Rosetta Stone demonstrating the effects of anthropogenic aerosols on cloud radia-  

E-Print Network [OSTI]

the signatures of indirect aerosol effects (e.g. enhanced droplet concentration) caused by ship emissions. Key words:Ship tracks, cloud parameterization, indirect aerosol effect, effective radius, mean in preexisting marine stratiform clouds, and argued that ship tracks served as good examples of the Twomey effect

31

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

SciTech Connect (OSTI)

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

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

2012-08-15T23:59:59.000Z

32

Assessing the effects of anthropogenic aerosols on Pacific storm track using a multiscale global  

E-Print Network [OSTI]

, the aerosols have an indirect effect by serving as cloud condensation nuclei, and their interaction latent heating (6), leading to an enhanced pre- cipitation efficiency (7­12), invigorated convection Satellite Cloud Climatology Project and high-resolution infrared sounder. In addition, a trend of increasing

33

BNL | Aerosol, Cloud, Precipitation Interactions  

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

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

34

Direct and semidirect aerosol effects of southern African biomass burning aerosol  

E-Print Network [OSTI]

Direct and semidirect aerosol effects of southern African biomass burning aerosol Naoko Sakaeda,1 2011; published 21 June 2011. [1] Direct and semidirect radiative effects of biomass burning aerosols static stability. Over the entire region the overall TOA radiative effect from the biomass burning

Wood, Robert

35

Distinguishing Aerosol Impacts on Climate over the Past Century  

Science Journals Connector (OSTI)

Aerosol direct (DE), indirect (IE), and black carbonsnow albedo (BAE) effects on climate between 1890 and 1995 are compared using equilibrium aerosolclimate simulations in the Goddard Institute for Space Studies General Circulation Model ...

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

2009-05-01T23:59:59.000Z

36

ARM - Field Campaign - Carbonaceous Aerosol and Radiative Effects Study  

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

govCampaignsCarbonaceous Aerosol and Radiative Effects Study (CARES) govCampaignsCarbonaceous Aerosol and Radiative Effects Study (CARES) Campaign Links CARES Website Related Campaigns Carbonaceous Aerosol and Radiation Effects Study (CARES) - Surface Meteorological Sounding 2010.05.26, Zaveri, OSC Carbonaceous Aerosol and Radiation Effects Study (CARES) Photo-Acoustic Aerosol Light Absorption and Scattering 2010.05.26, Arnott, OSC Carbonaceous Aerosol and Radiative Effects Study (CARES): SMPS & CCN counter deployment during CARES/Cal-NEx 2010.05.04, Wang, OSC Carbonaceous Aerosol and Radiative Effects Study (CARES) Ground Based Instruments 2010.04.01, Cziczo, OSC Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Carbonaceous Aerosol and Radiative Effects Study (CARES)

37

ARM - Publications: Science Team Meeting Documents: A decade long aerosol  

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

A decade long aerosol and cloud statistics and aerosol indirect effect at A decade long aerosol and cloud statistics and aerosol indirect effect at the ARM SGP site Min, Qilong State University of New York at Albany Duan, Minzheng State University of New York at Albany Harrison, Lee State University of New York Joseph, Everette Howard University Twelve-year data of MFRSR and MWR have been used to derive aerosol and cloud optical properties at the ARM SGP. Diurnal, monthly, seasonal and interannual variability of aerosol (optical depth and Angstrom coefficient) and cloud (optical depth and effective radius) have been analyzed. We specially focused on aerosol-cloud interactions. We found a signature of indirect aerosol effect for summer data: increased aerosol index has a statistically-significant anti-correlation with mean effective radius. No

38

Technical Note: Estimating Aerosol Effects on Cloud Radiative Forcing  

SciTech Connect (OSTI)

Estimating anthropogenic aerosol effects on the planetary energy balance through the aerosol influence on clouds using the difference in cloud radiative forcing from simulations with and without anthropogenic emissions produces estimates that are positively biased. A more representative method is suggested using the difference in cloud radiative forcing calculated with aerosol radiative effects neglected. The method also yields an aerosol radiative forcing decomposition that includes a term quantifying the impact of changes in surface albedo. The method requires only two additional diagnostic calculations: the whole-sky and clear-sky top-of-atmosphere radiative flux with aerosol radiative effects neglected.

Ghan, Steven J.

2013-10-09T23:59:59.000Z

39

Improving Bulk Microphysics Parameterizations in Simulations of Aerosol Effects  

SciTech Connect (OSTI)

To improve the microphysical parameterizations for simulations of the aerosol indirect effect (AIE) in regional and global climate models, a double-moment bulk microphysical scheme presently implemented in the Weather Research and Forecasting (WRF) model is modified and the results are compared against atmospheric observations and simulations produced by a spectral bin microphysical scheme (SBM). Rather than using prescribed aerosols as in the original bulk scheme (Bulk-OR), a prognostic doublemoment aerosol representation is introduced to predict both the aerosol number concentration and mass mixing ratio (Bulk-2M). The impacts of the parameterizations of diffusional growth and autoconversion and the selection of the embryonic raindrop radius on the performance of the bulk microphysical scheme are also evaluated. Sensitivity modeling experiments are performed for two distinct cloud regimes, maritime warm stratocumulus clouds (SC) over southeast Pacific Ocean from the VOCALS project and continental deep convective clouds (DCC) in the southeast of China from the Department of Energy/ARM Mobile Facility (DOE/AMF) - China field campaign. The results from Bulk-2M exhibit a much better agreement in the cloud number concentration and effective droplet radius in both the SC and DCC cases with those from SBM and field measurements than those from Bulk-OR. In the SC case particularly, Bulk-2M reproduces the observed drizzle precipitation, which is largely inhibited in Bulk-OR. Bulk-2M predicts enhanced precipitation and invigorated convection with increased aerosol loading in the DCC case, consistent with the SBM simulation, while Bulk-OR predicts the opposite behaviors. Sensitivity experiments using four different types of autoconversion schemes reveal that the autoconversion parameterization is crucial in determining the raindrop number, mass concentration, and drizzle formation for warm 2 stratocumulus clouds. An embryonic raindrop size of 40 ?m is determined as a more realistic setting in the autoconversion parameterization. The saturation adjustment employed in calculating condensation/evaporation in the bulk scheme is identified as the main factor responsible for the large discrepancies in predicting cloud water in the SC case, suggesting that an explicit calculation of diffusion growth with predicted supersaturation is necessary for further improvements of the bulk microphysics scheme. Lastly, a larger rain evaporation rate below cloud is found in the bulk scheme in comparison to the SBM simulation, which could contribute to a lower surface precipitation in the bulk scheme.

Wang, Yuan; Fan, Jiwen; Zhang, Renyi; Leung, Lai-Yung R.; Franklin, Charmaine N.

2013-06-05T23:59:59.000Z

40

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

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

govCampaignsBiogenic Aerosols - Effects on Clouds and Climate: govCampaignsBiogenic Aerosols - Effects on Clouds and Climate: FIGAERO-ToF-CIMS Instrument in Hyytiala with AMF-2 Related Campaigns Biogenic Aerosols- Effects on Clouds and Climate 2014.02.01, Petäjä, AMF Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Biogenic Aerosols - Effects on Clouds and Climate: FIGAERO-ToF-CIMS Instrument in Hyytiala with AMF-2 2014.04.01 - 2014.06.01 Lead Scientist : Joel Thornton Description The ultimate goal of this work is to connect field and laboratory observations of organic aerosol chemical and physical properties during the nascent growth stage to the diurnal and vertical distributions of aerosol abundance measured over the boreal forest by the ARM Mobile Facility 2

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


41

Direct and semidirect aerosol effects of Southern African biomass burning aerosol  

SciTech Connect (OSTI)

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

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

2011-06-21T23:59:59.000Z

42

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

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

govCampaignsBiogenic Aerosols - Effects on Clouds and Climate: Snowfall govCampaignsBiogenic Aerosols - Effects on Clouds and Climate: Snowfall Experiment Related Campaigns Biogenic Aerosols- Effects on Clouds and Climate 2014.02.01, Petäjä, AMF Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Biogenic Aerosols - Effects on Clouds and Climate: Snowfall Experiment 2014.02.01 - 2014.04.30 Lead Scientist : Dmitri Moisseev Description The snowfall measurement campaign, which will take place during AMF2 deployment in Finland, will focus on understanding snowfall microphysics and characterizing performance of surface based snowfall measurement instruments. This will be achieved by combining triple frequency (X, Ka, W -band) radar observations of vertical structure of the precipitation,

43

Effects of aerosols on deep convective cumulus clouds  

E-Print Network [OSTI]

This work investigates the effects of anthropogenic aerosols on deep convective clouds and the associated radiative forcing in the Houston area. The Goddard Cumulus Ensemble model (GCE) coupled with a spectral-bin microphysics is employed...

Fan, Jiwen

2009-05-15T23:59:59.000Z

44

Conceptualizing and testing random indirect effects and moderated mediation in multilevel models: New procedures and recommendations  

E-Print Network [OSTI]

The authors propose new procedures for evaluating direct, indirect, and total effects in multilevel models when all relevant variables are measured at Level 1 and all effects are random. Formulas are provided for the mean ...

Bauer, D. J.; Preacher, K. J.; Gil, Karen M.

2006-01-01T23:59:59.000Z

45

ARM - Evaluation Product - Organic Aerosol Component VAP  

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

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

46

SPSS and SAS procedures for estimating indirect effects in simple mediation models  

E-Print Network [OSTI]

Researchers often conduct mediation analysis in order to indirectly assess the effect of a proposed cause on some outcome through a proposed mediator. The utility of mediation analysis stems from its ability to go beyond ...

Preacher, K. J.; Hayes, A. F.

2004-01-01T23:59:59.000Z

47

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

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

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

48

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

SciTech Connect (OSTI)

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.

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

2013-10-25T23:59:59.000Z

49

Aerosol Modeling at LLNL - Our capability, results, and perspective  

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

Aerosol Indirect Effects to Cloud Aerosol Indirect Effects to Cloud Parameterizations in Short-Range Weather Forecasts with CAM3 Over the Southern Great Plains during May 2003 IOP Lawrence Livermore National Laboratory This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344 Catherine Chuang, James Boyle Shaocheng Xie and James Kelly LLNL-POST-401948 March 11, 2008 Why are aerosol/cloud interactions important? The greatest uncertainty in the assessment of radiative forcing arises from the interactions of aerosols with clouds. Radiative forcing of climate between 1750 and 2005 (IPCC, 2007) Sources of uncertainty Emissions Gas to particle conversion Aerosol size distribution Linkage between aerosols

50

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

E-Print Network [OSTI]

of this research is to examine sea salt aerosols and their impact on polluted environments. Sea salt aerosols act as Cloud Condensation Nuclei (CCN) as well as providing a surface for heterogeneous reactions. Such reactions have implications for trace gases...

Benoit, Mark David

2013-02-06T23:59:59.000Z

51

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

SciTech Connect (OSTI)

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

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

2012-01-16T23:59:59.000Z

52

Importance of Iron Mineralogy to Aerosol Solubility: Potential Effects of  

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

Importance of Iron Mineralogy to Importance of Iron Mineralogy to Aerosol Solubility: Potential Effects of Aerosol Source on Ocean Photosynthesis figure 1 Figure 1. Dust storm blowing glacial dusts from the Copper River Basin of southeast Alaska into the North Pacific Ocean, which depends on this and other external iron sources to support its biological communities. (Image: NASA MODIS satellite image, Nov. 1, 2006. http://earthobservatory.nasa.gov/IOTD/view.php?id=7094) Iron is one of the most important elements to life. Despite its paramount importance and relative abundance, dissolved iron concentrations are often very low, in part due to the formation of very stable iron minerals in most oxidizing environments. Since soluble iron is available to living organisms, iron deficiencies are widespread, and the factors that influence

53

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

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

An Observed Signature of Aerosol Effect on Cloud Droplet Radii from a An Observed Signature of Aerosol Effect on Cloud Droplet Radii from a Decade of Observations at a Mid-Continental Site Min, Qilong State University of New York at Albany Duan, Minzheng State University of New York at Albany Harrison, Lee State University of New York Joseph, Everette Howard University Category: Aerosols Continuing observations of aerosol and cloud optical property have been made using MFRSR and MWR at the ARM SGP site since 1993. Diurnal, monthly, seasonal and interannual variability of aerosol (optical depth and Angstrom coefficient) and cloud (optical depth and effective radius) have been analyzed. We have correlated an "aerosol index" computed from clear-sky observations of MFRSR with cloud droplet mean effective radius to study the

54

Direct and semi-direct radiative effects of anthropogenic aerosols in the Western United States: Seasonal  

E-Print Network [OSTI]

a regional climate model (RCM) in conjunction with the aerosol fields from a GEOS-Chem chemical- transport emissions and the seasonal low-level winds. The RCM-simulated anthropogenic aerosol radiative effects vary, respectively, following the seasonal AOD. In Arizona-New Mexico (AZNM), the effect of anthropogenic sulfates

Liou, K. N.

55

Direct radiative effect of aerosols emitted by transport from road, shipping and  

E-Print Network [OSTI]

Direct radiative effect of aerosols emitted by transport from road, shipping and aviation 1234567.0 License. Atmospheric Chemistry and Physics Direct radiative effect of aerosols emitted by transport: from road, shipping and aviation Y. Balkanski1, G. Myhre2,3, M. Gauss2,*, G. R�adel4, E. J. Highwood4, and K

Wirosoetisno, Djoko

56

Processes limiting the emergence of detectable aerosol indirect effects on tropical warm clouds in global  

E-Print Network [OSTI]

and HARTMUT GRA?L2 , 1 ARC Centre of Excellence for Climate System Science, School of Mathematical Sciences oxidation pathways is very low and ii) a possible observational signal is blurred out by high variability of buffering mechanisms on micro- and macroscopic scales which limit the emergence of such climate forcings

Peters, Karsten

57

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

E-Print Network [OSTI]

Supercomputing through a grant of computer time. The GFDLand NASA grant NNX08AL83G and acknowledge computer time

Quaas, Johannes

2010-01-01T23:59:59.000Z

58

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

E-Print Network [OSTI]

Supercomputing through a grant of computer time. The GFDLand NASA grant NNX08AL83G and acknowledge computer time

Quaas, Johannes

2010-01-01T23:59:59.000Z

59

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

E-Print Network [OSTI]

Evaluation of HadGEM2 model, Hadley Centre Technical Noteclimate sensitivity in the Hadley Centre climate model, J.DFG). The Met Office Hadley Centre is funded by the Joint

Quaas, Johannes

2010-01-01T23:59:59.000Z

60

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

E-Print Network [OSTI]

Evaluation of HadGEM2 model, Hadley Centre Technical Noteclimate sensitivity in the Hadley Centre climate model, J.ETH Zurich, Switzerland 9 Hadley Centre for Climate Change /

Quaas, Johannes

2010-01-01T23:59:59.000Z

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


61

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

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

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.

Sedlacek, Art

62

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

SciTech Connect (OSTI)

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.

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

63

Direct and indirect effects of southern flounder predation on a spot population: Experimental and model analyses  

SciTech Connect (OSTI)

We have previously shown that southern flounder (Paralichthys lethostigma Jordan and Gilbert) influence the survival and size-distribution of spot (Leiostomus xanthurus Lafayette) and other small estuarine fishes in experimental ponds. In this paper, we seek to determine whether these of effects can be accounted for by direct size-dependent predation or if there is also evidence for indirect behavioral effects on spot foraging which might alter their survival or population size structure. In our experiment, spot were allowed to grow in the presence and absence of southern flounder in an experimental estuarine pond for 101 days. Each treatment was replicated three times. We also apply a recently published simulation model of the flounder-spot interaction to this experiment to independently test the model and to estimate the direct effects of flounder predation on spot survival and size structure.

Crowder, L.B.; Wright, R.A.; Martin, T.H.; Rice, J.A. (North Carolina State Univ., Raleigh, NC (United States). Dept. of Zoology); Rose, K.A. (Oak Ridge National Lab., TN (United States))

1992-01-01T23:59:59.000Z

64

Direct and indirect effects of southern flounder predation on a spot population: Experimental and model analyses  

SciTech Connect (OSTI)

We have previously shown that southern flounder (Paralichthys lethostigma Jordan and Gilbert) influence the survival and size-distribution of spot (Leiostomus xanthurus Lafayette) and other small estuarine fishes in experimental ponds. In this paper, we seek to determine whether these of effects can be accounted for by direct size-dependent predation or if there is also evidence for indirect behavioral effects on spot foraging which might alter their survival or population size structure. In our experiment, spot were allowed to grow in the presence and absence of southern flounder in an experimental estuarine pond for 101 days. Each treatment was replicated three times. We also apply a recently published simulation model of the flounder-spot interaction to this experiment to independently test the model and to estimate the direct effects of flounder predation on spot survival and size structure.

Crowder, L.B.; Wright, R.A.; Martin, T.H.; Rice, J.A. [North Carolina State Univ., Raleigh, NC (United States). Dept. of Zoology; Rose, K.A. [Oak Ridge National Lab., TN (United States)

1992-12-31T23:59:59.000Z

65

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

E-Print Network [OSTI]

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...

Yi, Bingqi

2013-07-09T23:59:59.000Z

66

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

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

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

67

COATING AND MANDREL EFFECTS ON FABRICATION OF GLOW DISCHARGE POLYMER NIF SCALE INDIRECT DRIVE CAPSULES  

SciTech Connect (OSTI)

OAK A271 COATING AND MANDREL EFFECTS ON FABRICATION OF GLOW DISCHARGE POLYMER NIF SCALE INDIRECT DRIVE CAPSULES. Targets for the National Ignition Facility (NIF) need to be about 200 {micro}m thick and 2 mm in diameter. These dimensions are well beyond those currently fabricated on a routine basis. They have investigated fabrication of near NIF scale targets using the depolymerizable mandrel technique. Poly-alpha-methylstyrene (PAMS) mandrels, about 2 mm in diameter, of varying qualities were coated with as much as 125 {micro}m of glow discharge polymer (GDP). The surface finish of the final shells was examined using a variety of techniques. A clear dependence of the modal spectrum of final GDP shell on the quality of the initial PAMS mandrels was observed. isolated features were found to be the greatest cause for a shell not meeting the NIF standard.

NIKROO,A; PONTELANDOLFO,JM; CASTILLO,ER

2002-04-01T23:59:59.000Z

68

Contrasting the direct radiative effect and direct radiative forcing of aerosols  

E-Print Network [OSTI]

The direct radiative effect (DRE) of aerosols, which is the instantaneous radiative impact of all atmospheric particles on the Earth's energy balance, is sometimes confused with the direct radiative forcing (DRF), which ...

Heald, Colette L.

69

Effects of operating conditions on a heat transfer fluid aerosol  

E-Print Network [OSTI]

are made over ranges of temperature, pressure and orifice diameters. Aerosol drop size distributions of a HTF are measured by a non-intrusive method of analysis using a Malvern Laser Diffraction Particle Analyzer (Malvern laser). The Malvern laser employs...

Sukmarg, Passaporn

2012-06-07T23:59:59.000Z

70

About EffectiveŽ Height of the Aerosol Atmosphere in Visible and IR Wavelength Range  

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

"Effective" Height of the Aerosol Atmosphere in "Effective" Height of the Aerosol Atmosphere in Visible and IR Wavelength Range V. N. Uzhegov, D. M. Kabanov, M. V. Panchenko, Yu. A. Pkhalagov, and S. M. Sakerin Institute of Atmospheric Optics Tomsk, Russia Introduction Aerosol component of the atmosphere is one of the important factors affecting the radiation budget of the space - atmosphere - underlying surface system in visible and infrared (IR) wavelength ranges. It is extremely important to take into account the contribution of this component into the extinction of solar radiation under cloudless sky conditions. Sometimes it is important to know not only the total value of the aerosol component of extinction, but also to have the possibility to estimate the "effective" height of

71

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

SciTech Connect (OSTI)

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

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

2012-07-25T23:59:59.000Z

72

CARES: Carbonaceous Aerosol and Radiative Effects Study Operations Plan  

SciTech Connect (OSTI)

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.

Zaveri, RA; Shaw, WJ; Cziczo, DJ

2010-07-12T23:59:59.000Z

73

Overview of the 2010 Carbonaceous Aerosols and Radiative Effects Study (CARES)  

SciTech Connect (OSTI)

Substantial uncertainties still exist in the scientific understanding of the possible interactions between urban and natural (biogenic) emissions in the production and transformation of atmospheric aerosol and the resulting impact on climate change. The U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) program's Carbonaceous Aerosol and Radiative Effects Study (CARES) carried out in June 2010 in Central Valley, California, was a comprehensive effort designed to improve this understanding. The primary objective of the field study was to investigate the evolution of secondary organic and black carbon aerosols and their climate-related properties in the Sacramento urban plume as it was routinely transported into the forested Sierra Nevada foothills area. Urban aerosols and trace gases experienced significant physical and chemical transformations as they mixed with the reactive biogenic hydrocarbons emitted from the forest. Two heavily-instrumented ground sites - one within the Sacramento urban area and another about 40 km to the northeast in the foothills area - were set up to characterize the evolution of meteorological variables, trace gases, aerosol precursors, aerosol size, composition, and climate-related properties in freshly polluted and 'aged' urban air. On selected days, the DOE G-1 aircraft was deployed to make similar measurements upwind and across the evolving Sacramento plume in the morning and again in the afternoon. The NASA B-200 aircraft, carrying remote sensing instruments, was also deployed to characterize the vertical and horizontal distribution of aerosols and aerosol optical properties within and around the plume. This overview provides: a) the scientific background and motivation for the study, b) the operational and logistical information pertinent to the execution of the study, c) an overview of key observations and initial results from the aircraft and ground-based sampling platforms, and d) a roadmap of planned data analyses and focused modeling efforts that will facilitate the integration of new knowledge into improved representations of key aerosol processes in climate models.

Zaveri, Rahul A.; Shaw, William J.; Cziczo, D. J.; Schmid, Beat; Ferrare, R.; Alexander, M. L.; Alexandrov, Mikhail; Alvarez, R. J.; Arnott, W. P.; Atkinson, D.; Baidar, Sunil; Banta, Robert M.; Barnard, James C.; Beranek, Josef; Berg, Larry K.; Brechtel, Fred J.; Brewer, W. A.; Cahill, John F.; Cairns, Brian; Cappa, Christopher D.; Chand, Duli; China, Swarup; Comstock, Jennifer M.; Dubey, Manvendra K.; Easter, Richard C.; Erickson, Matthew H.; Fast, Jerome D.; Floerchinger, Cody; Flowers, B. A.; Fortner, Edward; Gaffney, Jeffrey S.; Gilles, Mary K.; Gorkowski, K.; Gustafson, William I.; Gyawali, Madhu S.; Hair, John; Hardesty, Michael; Harworth, J. W.; Herndon, Scott C.; Hiranuma, Naruki; Hostetler, Chris A.; Hubbe, John M.; Jayne, J. T.; Jeong, H.; Jobson, Bertram T.; Kassianov, Evgueni I.; Kleinman, L. I.; Kluzek, Celine D.; Knighton, B.; Kolesar, K. R.; Kuang, Chongai; Kubatova, A.; Langford, A. O.; Laskin, Alexander; Laulainen, Nels S.; Marchbanks, R. D.; Mazzoleni, Claudio; Mei, F.; Moffet, Ryan C.; Nelson, Danny A.; Obland, Michael; Oetjen, Hilke; Onasch, Timothy B.; Ortega, Ivan; Ottaviani, M.; Pekour, Mikhail S.; Prather, Kimberly A.; Radney, J. G.; Rogers, Ray; Sandberg, S. P.; Sedlacek, Art; Senff, Christoph; Senum, Gunar; Setyan, Ari; Shilling, John E.; Shrivastava, ManishKumar B.; Song, Chen; Springston, S. R.; Subramanian, R.; Suski, Kaitlyn; Tomlinson, Jason M.; Volkamer, Rainer M.; Wallace, Hoyt A.; Wang, J.; Weickmann, A. M.; Worsnop, Douglas R.; Yu, Xiao-Ying; Zelenyuk, Alla; Zhang, Qi

2012-08-22T23:59:59.000Z

74

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

SciTech Connect (OSTI)

Cloud and aerosol data acquired by the National Research Council of Canada (NRC) Convair-580 aircraft in, above, and below single-layer arctic stratocumulus cloud during the Indirect and Semi-Direct Aerosol Campaign (ISDAC) in April 2008 were used to test three aerosol indirect effects hypothesized to act in mixed-phase clouds: the riming indirect effect, the glaciation indirect effect, and the cold second indirect effect. The data showed a correlation of R= 0.75 between liquid drop number concentration, Nliq, inside cloud and ambient aerosol number concentration NPCASP below cloud. This, combined with increasing liquid water content LWC with height above cloud base and the nearly constant profile of Nliq, suggested that liquid drops were nucleated from aerosol at cloud base. No strong evidence of a riming indirect effect was observed, but a strong correlation of R = 0.69 between ice crystal number concentration Ni and NPCASP above cloud was noted. Increases in ice nuclei (IN) concentration with NPCASP above cloud combined with the subadiabatic LWC profiles suggest possible mixing of IN from cloud top consistent with the glaciation indirect effect. The higher Nice and lower effective radius rel for the more polluted ISDAC cases compared to data collected in cleaner single-layer stratocumulus conditions during the Mixed-Phase Arctic Cloud Experiment is consistent with the operation of the cold second indirect effect. However, more data in a wider variety of meteorological and surface conditions, with greater variations in aerosol forcing, are required to identify the dominant aerosol forcing mechanisms in mixed-phase arctic clouds.

Jackson, Robert C.; McFarquhar, Greg; Korolev, Alexei; Earle, Michael; Liu, Peter S.; Lawson, R. P.; Brooks, Sarah D.; Wolde, Mengistu; Laskin, Alexander; Freer, Matthew

2012-08-14T23:59:59.000Z

75

Evaluate and characterize mechanisms controlling transport, fate, and effects of army smokes in the aerosol wind tunnel: Transport, transformations, fate, and terrestrial ecological effects of hexachloroethane obscurant smokes  

SciTech Connect (OSTI)

The terrestrial transport, chemical fate, and ecological effects of hexachloroethane (HC) smoke were evaluated under controlled wind tunnel conditions. The primary objectives of this research program are to characterize and assess the impacts of smoke and obscurants on: (1) natural vegetation characteristic of US Army training sites in the United States; (2) physical and chemical properties of soils representative of these training sites; and (3) soil microbiological and invertebrate communities. Impacts and dose/responses were evaluated based on exposure scenarios, including exposure duration, exposure rate, and sequential cumulative dosing. Key to understanding the environmental impacts of HC smoke/obscurants is establishing the importance of environmental parameters such as relative humidity and wind speed on airborne aerosol characteristics and deposition to receptor surfaces. Direct and indirect biotic effects were evaluated using five plant species and two soil types. HC aerosols were generated in a controlled atmosphere wind tunnel by combustion of hexachloroethane mixtures prepared to simulate normal pot burn rates and conditions. The aerosol was characterized and used to expose plant, soil, and other test systems. Particle sizes of airborne HC ranged from 1.3 to 2.1 {mu}m mass median aerodynamic diameter (MMAD), and particle size was affected by relative humidity over a range of 20% to 85%. Air concentrations employed ranged from 130 to 680 mg/m{sup 3}, depending on exposure scenario. Chlorocarbon concentrations within smokes, deposition rates for plant and soil surfaces, and persistence were determined. The fate of principal inorganic species (Zn, Al, and Cl) in a range of soils was assessed.

Cataldo, D.A.; Ligotke, M.W.; Bolton, H. Jr.; Fellows, R.J.; Van Voris, P.; McVeety, B.D.; Li, Shu-mei W.; McFadden, K.M.

1989-09-01T23:59:59.000Z

76

Enhancement factors for resuspended aerosol radioactivity: Effects of topsoil disturbance  

SciTech Connect (OSTI)

The enhancement factor for airborne radionuclides resuspended by wind is defined as the ratio of the activity density (Bq g{sup {minus}1}) in the aerosol to the activity density in the underlying surface of contaminated soil. Enhancement factors are useful for assessment of worst-case exposure scenarios and transport conditions, and are one of the criteria for setting environmental standards for radioactivity in soil. This paper presents results of experimental studies where resuspension of {sup 239}Pu was measured when air concentrations were equilibrated to the soil surface. Enhancement factors were observed for several types of man-made disturbances (bulldozer-blading, soil raking, vacuum-cleaning) and natural disturbances (springtime thaw, soil-drying, wildfire). For some cases, enhancement factors are compared over range of geographical locations (Bikini Atoll, California, Nevada, and South Carolina). The particle-size distributions of aerosol activity are compared to particle-size distributions of the underlying soil.

Shinn, J.H.

1991-11-01T23:59:59.000Z

77

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

SciTech Connect (OSTI)

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

Penner, Joyce

2012-06-30T23:59:59.000Z

78

The Relative Effects of Direct and Indirect Actions of Ionizing Radiations on Deoxyribonucleic Acid  

Science Journals Connector (OSTI)

...determined over a range of concentrations...means that over this range of concentration...independent of the dose rate and of the hardness of the radiations within the ranges used and identical...indirect actions of ionizing radiations on deoxyribonucleic...

1958-01-01T23:59:59.000Z

79

Net radiative effect of dust aerosols from satellite measurements over Sahara  

E-Print Network [OSTI]

's Radiant Energy System (CERES) to calculate the top-of-atmosphere SW and LW flux radiative effect due to oceans where the shortwave effect dominates. Citation: Yang, E.-S., P. Gupta, and S. A. Christopher (2009 of aerosols, space-borne sensors use information from the ultraviolet (UV) to the visible and thermal infrared

Christopher, Sundar A.

80

The Effect of Non-Lambertian Surface Reflectance on Aerosol Radiative Forcing  

SciTech Connect (OSTI)

Surface reflectance is an important factor in determining the strength of aerosol radiative forcing. Previous studies of radiative forcing assumed that the reflected surface radiance is isotropic and does not depend on incident illumination angle. This Lambertian reflection model is not a very good descriptor of reflectance from real land and ocean surfaces. In this study we present computational results for the seasonal average of short and long wave aerosol radiative forcing at the top of the atmosphere and at the surface. The effect of the Lambertian assumption is found through comparison with calculations using a more detailed bi-direction reflectance distribution function (BRDF).

Ricchiazzi, P.; O'Hirok, W.; Gautier, C.

2005-03-18T23:59:59.000Z

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


81

AEROSOL DIRECT RADIATIVE EFFECTS OVER THE NORTHWEST ATLANTIC, NORTHWEST PACIFIC, AND NORTH INDIAN OCEANS  

E-Print Network [OSTI]

AEROSOL DIRECT RADIATIVE EFFECTS OVER THE NORTHWEST ATLANTIC, NORTHWEST PACIFIC, AND NORTH INDIAN, NORTHWEST PACIFIC, AND NORTH INDIAN OCEANS: ESTIMATES BASED ON IN-SITU CHEMICAL AND OPTICAL MEASUREMENTS, Y.24 , Tang, Y.25 , Weber, R. J.26 , and Wu, Y.27 1 NOAA/PMEL, 7600 Sand Point Way NE, Seattle, WA

82

Representing Cloud Processing of Aerosol in Numerical Models  

SciTech Connect (OSTI)

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

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

2005-03-18T23:59:59.000Z

83

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

SciTech Connect (OSTI)

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.

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

84

Aerosol climate effects and air quality impacts from 1980 to 2030  

E-Print Network [OSTI]

Aerosol climate e?ects and air quality impacts from 1980 toAerosol climate e?ects and air quality impacts from 1980 toAerosol climate e?ects and air quality impacts from 1980 to

Menon, Surabi

2008-01-01T23:59:59.000Z

85

Nonlinear Effects of Coexisting Surface and Atmospheric Forcing of Anthropogenic Absorbing Aerosols: Impact on the South Asian Monsoon Onset  

E-Print Network [OSTI]

The direct radiative effect of absorbing aerosols consists of absorption-induced atmospheric heating together with scattering- and absorption-induced surface cooling. It is thus important to understand whether some of the ...

Lee, Shao-Yi

86

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

E-Print Network [OSTI]

The aerosol direct and indirect effects were investigated for three specific cases during the March 2000 Cloud IOP at the SGP site by using a modified WRF model. The WRF model was previously altered to include a two-moment bulk microphysical scheme...

Vogel, Jonathan 1988-

2012-08-21T23:59:59.000Z

87

The Two-Column Aerosol Project (TCAP) Science Plan  

SciTech Connect (OSTI)

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

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

2011-07-27T23:59:59.000Z

88

Evaluate and characterize mechanisms controlling transport, fate and effects of army smokes in an aerosol wind tunnel: Transport, transformations, fate and terrestrial ecological effects of fog oil obscurant smokes: Final report  

SciTech Connect (OSTI)

The terrestrial transport, chemical fate, and ecological effects of fog oil (FO) smoke obscurants were evaluated under controlled wind tunnel conditions. The primary objectives of this research program are to characterize and assess the impacts of smoke and obscurants on: (1) natural vegetation characteristic of US Army training sites in the United States; (2) physical and chemical properties of soils representative of these training sites; and (3) soil microbiological and invertebrate communities. Impacts and dose/responses were evaluated based on an exposure scenario, including exposure duration, exposure rate, and sequential cumulative dosing. Key to understanding the environmental impacts of fog oil smoke/obscurants is establishing the importance of environmental parameters, such as relative humidity and wind speed on airborne aerosol characteristics and deposition to receptor surfaces. Direct and indirect biotic effects were evaluated using five plant species and three soil types. 29 refs., 35 figs., 32 tabs.

Cataldo, D.A.; Van Voris, P.; Ligotke, M.W.; Fellows, R.J.; McVeety, B.D.; Li, Shu-mei W.; Bolton, H. Jr.; Fredrickson, J.K.

1989-01-01T23:59:59.000Z

89

ARM - Field Campaign - Biogenic Aerosols - Effects on Clouds...  

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

(pressure temperature and relative humidity (RH)) to be obtained cost-effectively. Sensors developed at Reading include a supercooled liquid water sensor, an active cloud...

90

Direct and Indirect Effects of Agrochemicals on Bacterial Pathogens and Fecal Indicator Bacteria.  

E-Print Network [OSTI]

??The presence of agrochemical residues in both urban and agricultural water bodies has become ubiquitous, often producing deleterious effects in the impacted watershed including reductions (more)

Staley, Zachery

2013-01-01T23:59:59.000Z

91

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

SciTech Connect (OSTI)

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

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

2009-03-05T23:59:59.000Z

92

Effects of aerosol and horizontal inhomogeneity on the broadband albedo of marine stratus: Numerical simulations  

SciTech Connect (OSTI)

Recent estimates of the effect of increasing of anthropogenic sulfate aerosol on the radiative forcing of the atmosphere have indicated that its impact may be comparable in magnitude to the effect from increases in CO{sub 2}. Much of this impact is expected from the effects of the aerosol on cloud microphysics and the subsequent impact on cloud albedo. A solar broadband version of a 2D radiative transfer model was used to quantify the impact of enhanced aerosol concentrations and horizontal inhomogeneity on the solar broadband albedo of marine stratus. The results of the radiative transfer calculations indicated that in unbroken marine stratus clouds the net horizontal transport of photons over a domain of a few kilometers was nearly zero, and the domain-average broadband albedo computed in a 2D cross section was nearly identical to the domain average calculated from a series of independent pixel approximation (IPA) calculations of the same cross section. However, the horizontal inhomogeneity does affect the cloud albedo compared to plane-parallel approximation (PPA) computations due to the nonlinear relationship between albedo and optical depth. The reduction in cloud albedo could be related to the variability of the distribution of log (cloud optical depth). These results extend the finding of Cahalan et al. to broadband solar albedos in a more realistic cloud model and suggest that accurate computation of domain-averaged broadband albedos in unbroken (or nearly unbroken) marine stratus can be made using IPA calculations with 1D radiative transfer models. Computations of the mean albedo over portions of the 3D RAMS domain show the relative increase in cloud albedo due to a 67% increase in the boundary-layer average CCN concentration was between 6% and 9%. The effects of cloud inhomogeneity on the broadband albedo as measured from the PPA bias ranged from 3% to 5%. 25 refs., 8 figs., 4 tabs.

Duda, D.P.; Stephens, G.L.; Stevens, B.; Cotton, W.R. [Colorado State Univ., Fort Collins, CO (United States)] [Colorado State Univ., Fort Collins, CO (United States)

1996-12-15T23:59:59.000Z

93

Transport and Mixing Patterns over Central California during the Carbonaceous Aerosol and Radiative Effects Study (CARES)  

SciTech Connect (OSTI)

We describe the synoptic and regional-scale meteorological conditions that affected the transport and mixing of trace gases and aerosols in the vicinity of Sacramento, California during June 2010 when the Carbonaceous Aerosol and Radiative Effects Study (CARES) was conducted. The meteorological measurements collected by various instruments deployed during the campaign and the performance of the chemistry version of the Weather Research and Forecasting model (WRF-Chem) are both discussed. WRF-Chem was run daily during the campaign to forecast the spatial and temporal variation of carbon monoxide emitted from 20 anthropogenic source regions in California to guide aircraft sampling. The model is shown to reproduce the overall circulations and boundary-layer characteristics in the region, although errors in the upslope wind speed and boundary-layer depth contribute to differences in the observed and simulated carbon monoxide. Thermally-driven upslope flows that transported pollutants from Sacramento over the foothills of the Sierra Nevada occurred every afternoon, except during three periods when the passage of mid-tropospheric troughs disrupted the regional-scales flow patterns. The meteorological conditions after the passage of the third trough were the most favorable for photochemistry and likely formation of secondary organic aerosols. Meteorological measurements and model forecasts indicate that the Sacramento pollutant plume was likely transported over a downwind site that collected trace gas and aerosol measurements during 23 periods; however, direct transport occurred during only eight of these periods. The model also showed that emissions from the San Francisco Bay area transported by intrusions of marine air contributed a large fraction of the carbon monoxide in the vicinity of Sacramento, suggesting that this source likely affects local chemistry. Contributions from other sources of pollutants, such as those in the Sacramento Valley and San Joaquin Valley, were relatively low. Aerosol layering in the free troposphere was observed during the morning by an airborne Lidar; WRF-Chem forecasts showed that mountain venting processes contributed to aged pollutants aloft in the valley atmosphere which then can be entrained into the growing boundary layer the subsequent day.

Fast, Jerome D.; Gustafson, William I.; Berg, Larry K.; Shaw, William J.; Pekour, Mikhail S.; Shrivastava, ManishKumar B.; Barnard, James C.; Ferrare, R.; Hostetler, Chris A.; Hair, John; Erickson, Matthew H.; Jobson, Tom; Flowers, Bradley; Dubey, Manvendra K.; Springston, Stephen R.; Pirce, Bradley R.; Dolislager, Leon; Pederson, J. R.; Zaveri, Rahul A.

2012-02-17T23:59:59.000Z

94

Transport and mixing patterns over Central California during the carbonaceous aerosol and radiative effects study (CARES)  

SciTech Connect (OSTI)

We describe the synoptic and regional-scale meteorological conditions that affected the transport and mixing of trace gases and aerosols in the vicinity of Sacramento, California during June 2010 when the Carbonaceous Aerosol and Radiative Effects Study (CARES) was conducted. The meteorological measurements collected by various instruments deployed during the campaign and the performance of the chemistry version of the Weather Research and Forecasting model (WRF-Chem) are both discussed. WRF-Chem was run daily during the campaign to forecast the spatial and temporal variation of carbon monoxide emitted from 20 anthropogenic source regions in California to guide aircraft sampling. The model is shown to reproduce the overall circulations and boundary-layer characteristics in the region, although errors in the upslope wind speed and boundary-layer depth contribute to differences in the observed and simulated carbon monoxide. Thermally-driven upslope flows that transported pollutants from Sacramento over the foothills of the Sierra Nevada occurred every afternoon, except during three periods when the passage of mid-tropospheric troughs disrupted the regional-scale flow patterns. The meteorological conditions after the passage of the third trough were the most favorable for photochemistry and likely formation of secondary organic aerosols. Meteorological measurements and model forecasts indicate that the Sacramento pollutant plume was likely transported over a downwind site that collected trace gas and aerosol measurements during 23 time periods; however, direct transport occurred during only eight of these periods. The model also showed that emissions from the San Francisco Bay area transported by intrusions of marine air contributed a large fraction of the carbon monoxide in the vicinity of Sacramento, suggesting that this source likely affects local chemistry. Contributions from other sources of pollutants, such as those in the Sacramento Valley and San Joaquin Valley, were relatively low. Aerosol layering in the free troposphere was observed during the morning by an airborne Lidar. WRF-Chem forecasts showed that mountain venting processes contributed to aged pollutants aloft in the valley atmosphere that are then entrained into the growing boundary layer the subsequent day.

Fast J. D.; Springston S.; GustafsonJr., W. I.; Berg, L. K.; Shaw, W. J.; Pekour, M.; Shrivastava, M.; Barnard, J. C.; Ferrare, R. A.; Hostetler, C. A.; Hair, J. A.; Erickson, M.; Jobson, B. T.; Flowers, B.; Dubey, M. K.; Pierce, R. B.; Dolislager, L.; Pederson, J.; Zaveri, R. A.

2012-02-17T23:59:59.000Z

95

3D EFFECTS ON SPECTRALLY INVARIANT BEHAVIOR NEAR CLOUD EDGES: IMPLICATIONS FOR RETRIEVING AEROSOL AND CLOUD PROPERTIES IN  

E-Print Network [OSTI]

3D EFFECTS ON SPECTRALLY INVARIANT BEHAVIOR NEAR CLOUD EDGES: IMPLICATIONS FOR RETRIEVING AEROSOL between cloudy and clear air is always ambiguous, and because effects of the 3D nature of clouds will demonstrate how 3D effects may modulate the spectrally invariant relationships. We will also show the extent

96

Climate effects of seasonally varying Biomass Burning emitted Carbonaceous Aerosols (BBCA)  

E-Print Network [OSTI]

The climate impact of the seasonality of Biomass Burning emitted Carbonaceous Aerosols (BBCA) is studied using an aerosol-climate model coupled with a slab ocean model in a set of 60-year long simulations, driven by BBCA ...

Jeong, Gill-Ran

97

CHASER: An Innovative Satellite Mission Concept to Measure the Effects of Aerosols on Clouds and Climate  

E-Print Network [OSTI]

The formation of cloud droplets on aerosol particles, technically known as the activation of cloud condensation nuclei (CCN), is the fundamental process driving the interactions of aerosols with clouds and precipitation. ...

Rosenfeld, Daniel

98

aerosols | EMSL  

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

aerosols aerosols Leads No leads are available at this time. Magnesium behavior and structural defects in Mg+ ion implanted silicon carbide. Abstract: As a candidate material for...

99

Final Report for LDRD Project ''A New Era of Research in Aerosol/Cloud/Climate Interactions at LLNL''  

SciTech Connect (OSTI)

Observations of global temperature records seem to show less warming than predictions of global warming brought on by increasing concentrations of CO{sub 2} and other greenhouse gases. One of the reasonable explanations for this apparent inconsistency is that the increasing concentrations of anthropogenic aerosols may be partially counteracting the effects of greenhouse gases. Aerosols can scatter or absorb the solar radiation, directly change the planetary albedo. Aerosols, unlike CO{sub 2}, may also have a significant indirect effect by serving as cloud condensation nuclei (CCN). Increases in CCN can result in clouds with more but smaller droplets, enhancing the reflection of solar radiation. Aerosol direct and indirect effects are a strong function of the distributions of all aerosol types and the size distribution of the aerosol in question. However, the large spatial and temporal variabilities in the concentration, chemical characteristics, and size distribution of aerosols have made it difficult to assess the magnitude of aerosol effects on atmospheric radiation. These variabilities in aerosol characteristics as well as their effects on clouds are the leading sources of uncertainty in predicting future climate variation. Inventory studies have shown that the present-day anthropogenic emissions contribute more than half of fine particle mass primarily due to sulfate and carbonaceous aerosols derived from fossil fuel combustion and biomass burning. Parts of our earlier studies have been focused on developing an understanding of global sulfate and carbonaceous aerosol abundances and investigating their climate effects [Chuang et al., 1997; Penner et al., 1998]. We have also modeled aerosol optical properties to account for changes in the refractive indices with relative humidity and dry aerosol composition [Grant et al., 1999]. Moreover, we have developed parameterizations of cloud response to aerosol abundance for use in global models to evaluate the importance of aerosol/cloud interactions on climate forcing [Chuang and Penner, 1995]. Our research has been recognized as one of a few studies attempting to quantify the effects of anthropogenic aerosols on climate in the IPCC Third Assessment Report [IPCC, 2001]. Our previous assessments of aerosol climate effects were based on a general circulation model (NCAR CCM1) fully coupled to a global tropospheric chemistry model (GRANTOUR). Both models, however, were developed more than a decade ago. The lack of advanced physics representation and techniques in our current models limits us from further exploring the interrelationship between aerosol, cloud, and climate variation. Our objective is to move to a new era of aerosol/cloud/climate modeling at LLNL by coupling the most advanced chemistry and climate models and by incorporating an aerosol microphysics module. This modeling capability will enable us to identify and analyze the responsible processes in aerosol/cloud/climate interactions and therefore, to improve the level of scientific understanding for aerosol climate effects. This state-of-the-art coupled models will also be used to address the relative importance of anthropogenic and natural emissions in the spatial pattern of aerosol climate forcing in order to assess the potential of human induced climate change.

Chuang, C; Bergman, D J; Dignon, J E; Connell, P S

2002-01-31T23:59:59.000Z

100

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

SciTech Connect (OSTI)

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 (1.490.02) and effective density (1.680.21), 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.

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

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


101

Direct/Indirect Costs  

Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

This chapter provides recommended categories for direct and indirect elements developed by the Committee for Cost Methods Development (CCMD) and describes various estimating techniques for direct and indirect costs.

1997-03-28T23:59:59.000Z

102

Aerosol Radiative Effects and Single-Scattering Properties in the Tropical Western Pacific  

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

Effects and Single-Scattering Properties Effects and Single-Scattering Properties in the Tropical Western Pacific A. M. Vogelmann and P. J. Flatau Center for Atmospheric Sciences Scripps Institution of Oceanography University of California San Diego, California M. A. Miller, M. J. Bartholomew, and R. M. Reynolds Brookhaven National Laboratory Upton, New York P. J. Flatau University Corporation for Atmospheric Research Naval Research Laboratory Monterey, California K. M. Markowicz Institute of Geophysics University of Warsaw Warsaw, Poland Introduction The Atmospheric Radiation Measurement (ARM) Tropical Western Pacific (TWP) sites are downwind from Southeast Asia where biomass burning occurs and can advect over the tropical warm pool. Previous research (Vogelmann 2001, 2002, 2003) indicates that aerosol forcing was particularly large

103

Luminescence of coupled quantum wells:?Effects of indirect excitons in high in-plane magnetic fields  

Science Journals Connector (OSTI)

Luminescence measurements of a Ga1?xAlxAs?GaAs double quantum well in in-plane magnetic fields up to 22T are reported. The properties of spatially direct and indirect excitons are studied. We show that the strong indirect exciton luminescence survives in samples with low nonradiative recombination up to high in-plane magnetic fields. This contrasts with previously published results, where its strong suppression, observed for magnetic fields as low as of 10T, was explained by the exciton center-of-mass momentum conservation. We attribute the discrepancy to a relatively low nonradiative recombination in the studied sample in comparison with the radiative recombination of localized indirect excitons.

M. Orlita, R. Grill, M. Zvra, G. H. Dhler, S. Malzer, M. Byszewski, and J. Soubusta

2004-08-20T23:59:59.000Z

104

Distinguishing Aerosol Impacts on Climate Over the Past Century  

SciTech Connect (OSTI)

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

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

2008-08-22T23:59:59.000Z

105

Satellite-based assessment of cloud-free net radiative effect of dust aerosols over the Atlantic Ocean  

E-Print Network [OSTI]

and the Earth's Radiant Energy System (CERES) data from the Terra satellite over the Atlantic Ocean [10W­60W, 0 Ocean Sundar A. Christopher1 and Thomas Jones1 Received 7 August 2006; revised 8 November 2006; accepted effect (+1.44 ± 0.57 Wm?2 ) indicating the importance of the dust aerosols in the thermal portion

Christopher, Sundar A.

106

The effect of marine isoprene emissions on secondary organic aerosol and ozone formation in the coastal United States  

E-Print Network [OSTI]

The effect of marine isoprene emissions on secondary organic aerosol and ozone formation) in the coastal areas of the continental United States is studied using the U.S. Environmental Protection Agency regional-scale Community Multiscale Air Quality (CMAQ) modeling system. Marine isoprene emission rates

Zhang, Yang

107

Ganges Valley Aerosol Experiment: Science and Operations Plan  

SciTech Connect (OSTI)

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

Kotamarthi, VR

2010-06-21T23:59:59.000Z

108

Climate response of the South Asian monsoon system to anthropogenic aerosols  

SciTech Connect (OSTI)

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

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

2012-07-13T23:59:59.000Z

109

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

E-Print Network [OSTI]

of scale, in Air Pollution and Health in Rapidly Developingfor particulate air pollution health standards, Aerosolfor particulate air pollution health standards, Aerosol

Shields, Laura Grace

2008-01-01T23:59:59.000Z

110

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

E-Print Network [OSTI]

of levoglucosan in biomass combustion aerosol by high-and differences in biomass combustion smoke under differentwere unique to biomass combustion. Finally, the relative

Shields, Laura Grace

2008-01-01T23:59:59.000Z

111

E-Print Network 3.0 - aerosol chemical vapor Sample Search Results  

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

chemical and microphysical properties influence aerosol optical properties and radiative effects... distribution of aerosol extensive and intensive properties will aid ......

112

Effective Henry's Law Partitioning and the Salting Constant of Glyoxal in Aerosols Containing Sulfate  

E-Print Network [OSTI]

-resolved measurements of gas-phase and particle-phase concentrations in sulfate- containing aerosols. Two complementary utilizing filter sampling of chamber aerosols followed by HPLC-MS/MS analysis and (2) positive matrix and irreversible condensed-phase reactions of these compounds yield products of lower volatility; e.g. acetal

113

Aerosol optical properties and their radiative effects in northern Zhanqing Li,1,2,3  

E-Print Network [OSTI]

and may also affect the hydrologic cycle. By scattering and absorbing solar radiative energy, aerosols regions. The East Asian Study of Tropospheric Aerosols: An International Regional Experiment (EAST-AIRE on climate over China. This study presents some preliminary results using continuous high-quality

Dickerson, Russell R.

114

Assessing the effects of anthropogenic aerosols on Pacific storm track using a multiscale global climate model  

Science Journals Connector (OSTI)

...The first MMF model was built at the Colorado State University, replacing the cloud...microphysics of clouds. As an extension to the Colorado State University MMF, an aerosol version...715 737 . 4 Rosenfeld D ( 2008 ) Flood or drought: How do aerosols affect precipitation...

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

2014-01-01T23:59:59.000Z

115

On surface temperature, greenhouse gases, and aerosols: models and observations  

SciTech Connect (OSTI)

The effect of changes in atmospheric carbon dioxide concentrations and sulphate aerosols on near-surface temperature is investigated using a version of the Hadley Centre atmospheric model coupled to a mixed layer ocean. The scattering of sunlight by sulphate aerosols is represented by appropriately enhancing the surface albedo. On doubling atmospheric carbon dioxide concentrations, the global mean temperature increases by 5.2 K. An integration with a 39% increase in CO{sub 2}, giving the estimated change in radiative heating due to increases in greenhouse gases since 1900, produced an equilibrium warming of 2.3 K, which, even allowing for oceanic inertia, is significantly higher than the observed warming over the same period. Furthermore, the simulation suggests a substantial warming everywhere, whereas the observations indicate isolated regions of cooling, including parts of the northern midlatitude continents. The addition of an estimate of the effect of scattering by current industrial aerosols (uncertain by a factor of at least 3) leads to improved agreement with the observed pattern of changes over the northern continents and reduces the global mean warming by about 30%. Doubling the aerosol forcing produces patterns that are still compatible with the observations, but further increase leads to unrealistically extensive cooling in the midlatitudes. The diurnal range of surface temperature decreases over most of the northern extratropics on increasing CO{sub 2}, in agreement with recent observations. The addition of the current industrial aerosol had little detectable effect on the diurnal range in the model because the direct effect of reduced solar heating at the surface is approximately balanced by the indirect effects of cooling. Thus, the ratio of the reduction in diurnal range to the mean warming is increased, in closer agreement with observations. Results from further sensitivity experiments with larger increases in aerosol and CO{sub 2} are presented.

Mitchell, J.F.B.; Davis, R.A.; Ingram, W.J.; Senior, C.A. [Hadley Centre for Climate Prediction and Research, Berkshire (United Kingdom)] [Hadley Centre for Climate Prediction and Research, Berkshire (United Kingdom)

1995-10-01T23:59:59.000Z

116

Biomass Indirect Liquefaction Workshop  

Broader source: Energy.gov [DOE]

To support research and development (R&D) planning efforts within the Thermochemical Conversion Program, the Bioenergy Technologies Office hosted the Biomass Indirect Liquefaction (IDL)...

117

Aerosols in a Changing Atmosphere: From Detailed Aerosol Microphysics to  

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

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

118

Studying the feedback effects of aerosols on ozone and temperatures in Los Angeles with an Eulerian air pollution model  

SciTech Connect (OSTI)

An Eulerian air pollution model (GATOR/MMTD) was used to study the effects of aerosols on surface solar radiation, surface air temperatures, and ozone mixing ratios. Model results were also compared to data from the Southern California Air Quality Study (SCAQS) period of August 27-29, 1987. Gross errors for sulfate, sodium, light absorption, temperature, surface solar radiation, sulfur dioxide gas, formaldehyde gas, and ozone were lowest among parameters compared (1-40%). Gross errors for elemental carbon, organic carbon, total particulate mass, ammonium, ammonia gas, nitric acid gas, and light scattering, were larger (40-61%). Gross errors for particulate nitrate were largest (65-70%). Doubling of the land-based particulate emissions inventory caused gross errors of total particulate mass and elemental carbon to increase by factors of more than two. Also, setting lateral boundary inflow concentrations of particles to zero caused slight (< 1%) erosion of results for most species, large erosion (10%) for sodium and chloride, but slight improvement (< 1%) for a few species. Spinning up the meteorological model 24 hours in advance caused most gross errors to increase. Finally, model predictions for several parameters, with and without the inclusion of aerosols, were compared to data. The presence of aerosols reduced peak daytime surface solar radiation by approximately 6.4% (55 W m-2), increased night-time temperatures by about 0.77 K, decreased daytime temperatures by about 0.08 K, and increased overall temperatures (day plus night during the two day simulation period) by 0.43 K. The relatively small cooling during the day was due to heat trapping by elemental carbon-containing aerosols. The presence of aerosols also caused ozone mixing ratios to decrease by 2%.

Jacobson, M. [Stanford Univ., CA (United States)

1996-12-31T23:59:59.000Z

119

Overview of the 2010 Carbonaceous Aerosols and Radiative Effects Study (CARES)  

E-Print Network [OSTI]

Substantial uncertainties still exist in the scientific understanding of the possible interactions between urban and natural (biogenic) emissions in the production and transformation of atmospheric aerosol and the resulting ...

Cziczo, Daniel James

120

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

E-Print Network [OSTI]

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

Leibensperger, Eric Michael

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


121

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

SciTech Connect (OSTI)

In this DOE project the improvements to parameterization of marine primary organic matter (POM) emissions, hygroscopic properties of marine POM, marine isoprene derived secondary organic aerosol (SOA) emissions, surfactant effects, new cloud droplet activation parameterization have been implemented into Community Atmosphere Model (CAM 5.0), with a seven mode aerosol module from the Pacific Northwest National Laboratory (PNNL)???¢????????s Modal Aerosol Model (MAM7). The effects of marine aerosols derived from sea spray and ocean emitted biogenic volatile organic compounds (BVOCs) on microphysical properties of clouds were explored by conducting 10 year CAM5.0-MAM7 model simulations at a grid resolution 1.9???????°????????2.5???????° with 30 vertical layers. Model-predicted relationship between ocean physical and biological systems and the abundance of CCN in remote marine atmosphere was compared to data from the A-Train satellites (MODIS, CALIPSO, AMSR-E). Model simulations show that on average, primary and secondary organic aerosol emissions from the ocean can yield up to 20% increase in Cloud Condensation Nuclei (CCN) at 0.2% Supersaturation, and up to 5% increases in droplet number concentration of global maritime shallow clouds. Marine organics were treated as internally or externally mixed with sea salt. Changes associated with cloud properties reduced (absolute value) the model-predicted short wave cloud forcing from -1.35 Wm-2 to -0.25 Wm-2. By using different emission scenarios, and droplet activation parameterizations, this study suggests that addition of marine primary aerosols and biologically generated reactive gases makes an important difference in radiative forcing assessments. All baseline and sensitivity simulations for 2001 and 2050 using global-through-urban WRF/Chem (GU-WRF) were completed. The main objective of these simulations was to evaluate the capability of GU-WRF for an accurate representation of the global atmosphere by exploring the most accurate configuration of physics options in GWRF for global scale modeling in 2001 at a horizontal grid resolution of 1???????° x 1???????°. GU-WRF model output was evaluated using observational datasets from a variety of sources including surface based observations (NCDC and BSRN), model reanalysis (NCEP/ NCAR Reanalysis and CMAP), and remotely-sensed data (TRMM) to evaluate the ability of GU-WRF to simulate atmospheric variables at the surface as well as aloft. Explicit treatment of nanoparticles produced from new particle formation in GU-WRF/Chem-MADRID was achieved by expanding particle size sections from 8 to 12 to cover particles with the size range of 1.16 nm to 11.6 ???????µm. Simulations with two different nucleation parameterizations were conducted for August 2002 over a global domain at a 4???????º by 5???????º horizontal resolution. The results are evaluated against field measurement data from the 2002 Aerosol Nucleation and Real Time Characterization Experiment (ANARChE) in Atlanta, Georgia, as well as satellite and reanalysis data. We have also explored the relationship between ???¢????????clean marine???¢??????? aerosol optical properties and ocean surface wind speed using remotely sensed data from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) on board the CALIPSO satellite and the Advanced Microwave Scanning Radiometer (AMSR-E) on board the AQUA satellite. Detailed data analyses

Meskhidze, Nicholas; Zhang, Yang; Kamykowski, Daniel

2012-03-28T23:59:59.000Z

122

ARM - Field Campaign - Fall 1997 Aerosol IOP  

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

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

123

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

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

govCampaignsTwo-Column Aerosol Project (TCAP) govCampaignsTwo-Column Aerosol Project (TCAP) Campaign Links TCAP website Related Campaigns Two-Column Aerosol Project (TCAP): Field Evaluation of Real-time Cloud OD Sensor TWST 2013.04.15, Scott, AMF Two-Column Aerosol Project (TCAP): Winter Aerosol Effects on Cloud Formation 2013.02.04, Cziczo, AMF Two-Column Aerosol Project (TCAP): CU GMAX-DOAS Deployment 2012.07.15, Volkamer, AMF Two-Column Aerosol Project (TCAP): Aerosol Light Extinction Measurements 2012.07.15, Dubey, AMF Two-Column Aerosol Project (TCAP): Aerial Campaign 2012.07.07, Berg, AAF Two-Column Aerosol Project (TCAP): Aerodynamic Particle Sizer 2012.07.01, Berg, AMF Two-Column Aerosol Project (TCAP): KASPRR Engineering Tests 2012.07.01, Mead, AMF Two-Column Aerosol Project (TCAP): Airborne HSRL and RSP Measurements

124

EMSL: Science: Atmospheric Aerosol Systems  

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

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

125

Microphysical effects determine macrophysical response for aerosol impacts on deep convective clouds  

Science Journals Connector (OSTI)

...cycle extremes like droughts and floods (19). The risk of droughts...the risk of both droughts and floods could be higher due...122 . 24 Rosenfeld D ( 2008 ) Flood or drought: How do aerosols...Natl. Cent. for Atmos. Res. Boulder, CO ). 28 Korolev AV Mazin...

Jiwen Fan; L. Ruby Leung; Daniel Rosenfeld; Qian Chen; Zhanqing Li; Jinqiang Zhang; Hongru Yan

2013-01-01T23:59:59.000Z

126

Constraining the influence of natural variability to improve estimates of global aerosol indirect effects in a nudged version of the Community Atmosphere Model 5  

E-Print Network [OSTI]

of Energys (DOE) Office of Science, Office of Biologicalsupported by the DOE Office of Science, Decadal and Regionaland the DOEs Office of Science (BER). MACM was developed at

Kooperman, Gabriel J; Pritchard, Michael S; Ghan, Steven J; Wang, Minghuai; Somerville, Richard C. J; Russell, Lynn M

2012-01-01T23:59:59.000Z

127

Atmospheric Radiation Measurement (ARM) Data from Cape Cod, Massachusetts for the Two-Column Aerosol Project (TCAP)  

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

The Two-Column Aerosol Project (TCAP) was designed to 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 ARM Mobile Facility and the Mobile Aerosol Observing System were deployed 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 were supplemented by two aircraft intensive observation periods, one in the summer and a second in the winter.

128

Aerosol delivery of beclin1 enhanced the anti-tumor effect of radiation in the lungs of K-rasLA1 mice  

Science Journals Connector (OSTI)

......similar effects to using mTOR inhibitors (Fig.-3b, c). Akt1...Urocanic acid-modified chitosan-mediated PTEN delivery via...aerosol-delivered folate-chitosan-graft-polyethylenimine...Z-VAD, a pan-caspase inhibitor. Mol Cancer Ther (2009......

Ji-Young Shin; Hwang-Tae Lim; Arash Minai-Tehrani; Mi-Suk Noh; Ji-Eun Kim; Ji-Hye Kim; Hu-Lin Jiang; Rohidas Arote; Doo-Yeol Kim; Chanhee Chae; Kee-Ho Lee; Mi-Sook Kim; Myung-Haing Cho

2012-07-01T23:59:59.000Z

129

Experimental Investigation of the Effect of M-Band Preheating in Indirectly-Driven Double-Shell Implosions  

SciTech Connect (OSTI)

Experimental results are presented from several series of experiments studying the effect of 2-4 keV M-shell radiation on the implosion of double-shell capsules on the Omega Laser at the Laboratory for Laser Energetics. In the First series of experiments, precision machined double-shell capsules implosions are performed. A discrepancy is observed between the experimentally measured M-band fraction and the simulated value. The application of a time-dependent multiplier to the simulated M-band level results in a decrease in predicted yield of 35% and a corresponding increase in the YoC to 20-35%. In order to further investigate this discrepancy, a series of ''M-Band driven'' targets has been designed. An oversized outer shell is used to preferentially allow the M-band radiation to drive the implosion of a CH-tamped glass inner shell. The inner shell radius-time history is measured and is shown to be consistent with the simulations using the time-dependent M-band multipliers. The spatial distribution of this M-band source is also varied using hohlraums of different length and adjusting the laser pointing accordingly. The resulting asymmetry of the inner shell implosion is diagnosed both by x-ray backlighting prior to shell collision and by core emission.

Robey, H F; Amendt, P A; Park, H-S; Landen, O L; Watt, R G; Varnum, W S

2003-08-22T23:59:59.000Z

130

AEROgui: A graphical user interface for the optical properties of aerosols  

Science Journals Connector (OSTI)

Atmospheric aerosols have an uncertain effect on climate, and serious impact on human health. The uncertainty in the aerosols role on climate has several sources. First, aerosols present a great spatial and temporal variability. The spatial variability ...

R. Pedrs; J.L. Gmez-Amo; C.R. Marcos; M.P. Utrillas; S. Ganda; F. Tena; J.A. Martinez Lozano

131

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

SciTech Connect (OSTI)

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

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

2011-11-04T23:59:59.000Z

132

Aerosol retention during SGTR meltdown sequences: Experimental insights of the effect of size and shape of the breach  

SciTech Connect (OSTI)

This paper summarizes the major insights gained from aerosol retention capability of a tube bundle that simulates the break stage of the secondary side of a failed steam generator under dry SGTR conditions. This scenario is highly relevant in nuclear safety since it affects the potential retention of radioactive particles in case of meltdown sequences with a SGTR. An 8-test experimental campaign has been carried out, extending the current database on the decontamination capability of the steam generator. The effects of the breach features (shape and size) and the particle nature (SiO{sub 2} and TiO{sub 2}) on the collection efficiency have been explored. The results confirmed the strong effect of the physical nature even when tube breaks in a fish-mouth mode. Loose aggregates (i.e. TiO{sub 2}) would be trapped to a limited extent (less than 25%); while single- or few-aggregates (i.e. SiO{sub 2}) would undergo a quite effective removal (i.e. over 75%). For fish-mouth breaches and SiO{sub 2} particles, the breach size has been found to moderately affect retention efficiency. Furthermore, the breach shape does not seem to have any effect on the net collection efficiency within the break stage, no matter the particle type. However, individual tube measurements indicate notably different deposition patterns, although an effect of the facility geometry cannot be disregarded as a key player in this observation. (authors)

Herranz, L. E.; Tardaguila, R. D.; Lopez, C. [Unit of Nuclear Safety Research, CIEMAT, Avd. Complutense, 22, 28040 Madrid (Spain)

2012-07-01T23:59:59.000Z

133

E-Print Network 3.0 - aerosol particles originating Sample Search...  

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

the U.S. Department of Energy under Contract No. DE-AC02-98CH10886. Summary: incoming solar radiation, either directly or indirectly as cloud particles, aerosols exert a cooling...

134

Indirect CP violation results and HFAG averages  

E-Print Network [OSTI]

The current status of the search for indirect CP violation in the neutral D meson system at the B-factories and at LHCb is reported. The indirect CP asymmetry search is performed by the measurement of the proper-time asymmetry ($A_{\\Gamma}$) in decays of $D^0-\\bar{D^0}$ mesons to CP eigenstates, $K^-K^+$ and $\\pi^- \\pi^+$, and by $y_{CP}$, the ratio between the effective lifetime measured in decay to a CP eigenstate and that to the mixed eigenstate $K \\pi$. All results are consistent with the no CP violation hypothesis. The latest world averages for mixing and CP asymmetry in the charm sector evaluated by the Heavy Flavour Averaging Group are presented. The no mixing hypothesis is excluded at more than 12 standard deviations. The search for direct and indirect CP violation in the charm sector is consistent with no CP violation at 2.0% confident level.

Silvia Borghi

2013-12-17T23:59:59.000Z

135

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

SciTech Connect (OSTI)

This project examined the potential large-scale influence of marine aerosol cycling on atmospheric chemistry, physics and radiative transfer. Measurements indicate that the size-dependent generation of marine aerosols by wind waves at the ocean surface and the subsequent production and cycling of halogen-radicals are important but poorly constrained processes that influence climate regionally and globally. A reliable capacity to examine the role of marine aerosol in the global-scale atmospheric system requires that the important size-resolved chemical processes be treated explicitly. But the treatment of multiphase chemistry across the breadth of chemical scenarios encountered throughout the atmosphere is sensitive to the initial conditions and the precision of the solution method. This study examined this sensitivity, constrained it using high-resolution laboratory and field measurements, and deployed it in a coupled chemical-microphysical 3-D atmosphere model. First, laboratory measurements of fresh, unreacted marine aerosol were used to formulate a sea-state based marine aerosol source parameterization that captured the initial organic, inorganic, and physical conditions of the aerosol population. Second, a multiphase chemical mechanism, solved using the Max Planck Institute for Chemistry??s MECCA (Module Efficiently Calculating the Chemistry of the Atmosphere) system, was benchmarked across a broad set of observed chemical and physical conditions in the marine atmosphere. Using these results, the mechanism was systematically reduced to maximize computational speed. Finally, the mechanism was coupled to the 3-mode modal aerosol version of the NCAR Community Atmosphere Model (CAM v3.6.33). Decadal-scale simulations with CAM v.3.6.33, were run both with and without reactive-halogen chemistry and with and without explicit treatment of particulate organic carbon in the marine aerosol source function. Simulated results were interpreted (1) to evaluate influences of marine aerosol production on the microphysical properties of aerosol populations and clouds over the ocean and the corresponding direct and indirect effects on radiative transfer; (2) atmospheric burdens of reactive halogen species and their impacts on O3, NOx, OH, DMS, and particulate non-sea-salt SO42-; and (3) the global production and influences of marine-derived particulate organic carbon. The model reproduced major characteristics of the marine aerosol system and demonstrated the potential sensitivity of global, decadal-scale climate metrics to multiphase marine-derived components of Earth??s troposphere. Due to the combined computational burden of the coupled system, the currently available computational resources were the limiting factor preventing the adequate statistical analysis of the overall impact that multiphase chemistry might have on climate-scale radiative transfer and climate.

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

2013-05-20T23:59:59.000Z

136

Organic Aerosols in the Earth's J O O S T D E G O U W *  

E-Print Network [OSTI]

, and indirectly through their role as cloud-condensation nuclei. A large fraction (50%) of the submicron aerosol(primaryorganicaerosolorPOA) are distinguished from secondary organic aerosol (SOA) formed in the atmosphere from gas-phase precursors. Both POA scales of minutes: particle-into-liquid sampling combined with total organic carbon analysis for measure

Jimenez, Jose-Luis

137

Ship-Track Clouds, Aerosol, and Ship Dynamic Effects; A Climate Perspective from Ship-Based Measurements  

SciTech Connect (OSTI)

Ship-track clouds are marine boundary layer clouds that form behind ocean ships and are observed from satellites in the visible and near infrared. Ship-track clouds provide a rare opportunity to connect aerosol cloud condensation nuclei (CCN) emissions and observable changes in marine stratiform clouds. A very small change in the reflectivity of these eastern Pacific and Atlantic clouds (about 4%) provides a climate feedback of similar magnitude to doubling CO{sub 2} (increasing cloud reflectivity corresponds to global cooling). The Department of Energy sponsored research from 1991 to 1995 to study ship-track clouds including two ocean-based experiments in the summers of 1991 and 1994. These experiments showed that ship-track cloud properties were often more complex those related to a reduction of droplet size with an increase in number associated with increasing CCN from the ship's plume. The clouds showed evidence of morphological changes more likely to be associated with cloud dynamic effects either initiated by the increased CCN or directly by the ship's heat output or turbulent air wake. The fact that marine stratiform clouds, that are susceptible to ship track formation, are starved for both CCN and convective turbulence complicates the separation of the two effects.

Porch, W.M.

1998-10-13T23:59:59.000Z

138

TENORM aerosols in the Florida phosphate industry?assessment of lung fluid solubility and annual effective dose to workers  

Science Journals Connector (OSTI)

......Inhalation studies of uranium trioxide. Health Phys. 23 , 273-280...simulant solution. Health Phys. 43 , 663-668...vitro solubility of depleted uranium (DU) in aerosols produced...on armored vehicles. Health Phys. 82 , S157 (2002......

Kwang Pyo Kim; Chang-Yu Wu; Brian K. Birky; Wesley E. Bolch

2007-01-01T23:59:59.000Z

139

Calculation of direct and indirect excitons in GaAs?Ga1?xAlxAs coupled double quantum wells: The effects of in-plane magnetic fields and growth-direction electric fields  

Science Journals Connector (OSTI)

The variational procedure, in the effective-mass and parabolic-band approximations, is used in order to investigate the effects of crossed electric and magnetic fields on the exciton states in GaAs?Ga1?xAlxAs coupled double quantum wells. Calculations are performed for double quantum wells under applied magnetic fields parallel to the layers and electric fields in the growth direction. The exciton envelope wave function is obtained through a variational procedure using a hydrogenic 1s-like wave function and an expansion in a complete set of trigonometric functions for the electron and hole wave functions. We take into account intersubband mixing brought about by the Coulomb interaction of electron-hole pairs in double quantum wells and present a detailed analysis of the properties of direct and indirect exciton states in these systems. The present study clearly reveals anticrossing effects on the dispersion with applied voltage (or growth-direction electric field) of the photoluminescence peaks associated with direct and indirect excitons. Calculated results are found in good agreement with available experimental measurements on the photoluminescence peak position associated with direct and indirect excitons in GaAs-Ga1?xAlxAs double quantum wells under growth-direction applied electric fields or under applied in-plane magnetic fields.

M. de Dios-Leyva, C. A. Duque, and L. E. Oliveira

2007-08-02T23:59:59.000Z

140

Separating Cloud Forming Nuclei from Interstitial Aerosol  

SciTech Connect (OSTI)

It has become important to characterize the physicochemical properties of aerosol that have initiated the warm and ice clouds. The data is urgently needed to better represent the aerosol-cloud interaction mechanisms in the climate models. The laboratory and in-situ techniques to separate precisely the aerosol particles that act as cloud condensation nuclei (CCN) and ice nuclei (IN), termed as cloud nuclei (CN) henceforth, have become imperative in studying aerosol effects on clouds and the environment. This review summarizes these techniques, design considerations, associated artifacts and challenges, and briefly discusses the need for improved designs to expand the CN measurement database.

Kulkarni, Gourihar R.

2012-09-12T23:59:59.000Z

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


141

E-Print Network 3.0 - aerosol trapping effect Sample Search Results  

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

of this infrared radiation is trapped... 'S TEMPERATURE IS RISING This is the greenhouse effect. Without it, the Earths climate would be ... Source: Brookhaven National...

142

CLOUD DROPLET NUCLEATION AND ITS CONNECTION TO AEROSOL PROPERTIES  

E-Print Network [OSTI]

CLOUD DROPLET NUCLEATION AND ITS CONNECTION TO AEROSOL PROPERTIES STEPHEN E. SCHWARTZ Environmental in cloud-free conditions and indirectly, by increasing concentratiol1S of cloud droplets thereby enhancing cloud shortwave reflectivity. These effecls are thought to be significant in the context of changes

143

Impact of natural and anthropogenic aerosols on stratocumulus and precipitation in the Southeast Pacific: A regional modeling study using WRF-Chem  

SciTech Connect (OSTI)

Cloud-system resolving simulations with the chemistry version of the Weather Research and Forecasting (WRF-Chem) model are used to quantify the impacts of regional anthropogenic and oceanic emissions on changes in aerosol properties, cloud macro- and microphysics, and cloud radiative forcing over the Southeast Pacific (SEP) during the VAMOS Ocean-Cloud-Atmosphere-Land Study Regional Experiment (VOCALS-REx) (15 OctNov 16, 2008). The effects of oceanic aerosols on cloud properties, precipitation, and the shortwave forcing counteract those of anthropogenic aerosols. Despite the relatively small changes in Na concentrations (2-12%) from regional oceanic emissions, their net effect (direct and indirect) on the surface shortwave forcing is opposite and comparable or even larger in magnitude compared to those of regional anthropogenic emissions over the SEP. Two distinct regions are identified in the VOCALS-REx domain. The near-coast polluted region is characterized with strong droplet activation suppression of small particles by sea-salt particles, the more important role of the first than the second indirect effect, low surface precipitation rate, and low aerosol-cloud interaction strength associated with anthropogenic emissions. The relatively clean remote region is characterized with large contributions of Cloud Condensation Nuclei (CCN, number concentration denoted by NCCN) and droplet number concentrations (Nd) from non-local sources (lateral boundaries), a significant amount of surface precipitation, and high aerosol-cloud interactions under a scenario of five-fold increase in anthropogenic emissions. In the clean region, cloud properties have high sensitivity (e.g., 13% increase in cloud-top height and a 9% surface albedo increase) to the moderate increase in CCN concentration (?Nccn = 13 cm-3; 25%) produced by a five-fold increase in regional anthropogenic emissions. The increased anthropogenic aerosols reduce the precipitation amount over the relatively clean remote ocean. The reduction of precipitation (as a cloud water sink) more than doubles the wet scavenging timescale, resulting in an increased aerosol lifetime in the marine boundary layer. Therefore, the aerosol impacts on precipitation are amplified by the positive feedback of precipitation on aerosol. The positive feedback ultimately alters the cloud micro- and macro-properties, leading to strong aerosol-cloud-precipitation interactions. The higher sensitivity of clouds to anthropogenic aerosols over this region is also related to a 16% entrainment rate increase due to anthropogenic aerosols. The simulated aerosol-cloud-precipitation interactions are stronger at night over the clean marine region, while during the day, solar heating results in more frequent decoupling, thinner clouds, reduced precipitation, and reduced sensitivity to anthropogenic emissions. The simulated high sensitivity to the increased anthropogenic emissions over the clean region suggests that the perturbation of the clean marine environment with anthropogenic aerosols may have a larger effect on climate than that of already polluted marine environments.

Yang, Qing; Gustafson, William I.; Fast, Jerome D.; Wang, Hailong; Easter, Richard C.; Wang, Minghuai; Ghan, Steven J.; Berg, Larry K.; Leung, Lai-Yung R.; Morrison, H.

2012-09-28T23:59:59.000Z

144

A study on the effect of inlet turbulence on gas mixing for single point aerosol sampling  

E-Print Network [OSTI]

not be effective for achieving a uniform velocity profile. Numerical computations are performed with commercially available computational fluid dynamics (CFD) software (FLUENT[], Version 5.4), and the performance of the turbulence and particle tracking models...

Mohan, Anand

2012-06-07T23:59:59.000Z

145

Biomass Indirect Liquefaction Presentation | Department of Energy  

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

Biomass Indirect Liquefaction Presentation Biomass Indirect Liquefaction Presentation TRI Technology Update & IDL R&D Needs burciagatri.pdf More Documents & Publications...

146

The effect of preceding elbows on aerosol deposition in subsequent flow elements  

E-Print Network [OSTI]

of penetration and L/D[t] were used to compare the straight tube deposition with and without an upstream bend in the transport system. Deposition velocities were calculated from the penetration values and were used to develop a correlation. The effect...

Ramakrishna, Nagaraj

2012-06-07T23:59:59.000Z

147

Quantification of the Aerosol Direct Radiative Effect from Smoke over Clouds Using Passive Space-borne Spectrometry  

E-Print Network [OSTI]

, Wilhelminalaan 30, 3732 GK, De Bilt, The Netherlands email: graafdem@knmi.nl Abstract. The solar radiative the South Atlantic Ocean west of Africa on 13 August 2006, when a huge plume of smoke was present over: 92.70.Cp, 92.60.Mt, 92.60.Nv INTRODUCTION Aerosols play an important role in the global energy

Tilstra, Gijsbert

148

Effects of Black Carbon Aerosols on the Indian Monsoon GERALD A. MEEHL, JULIE M. ARBLASTER,* AND WILLIAM D. COLLINS  

E-Print Network [OSTI]

of the ABC on longwave radiation are contributed primarily by natural aerosols and are not appreciable combine with naturally occurring dust loading over the Tibetan Plateau to ac- centuate the elevated heat radiation reaching the surface during the dry season, as noted in previous studies. The increased meridional

Meehl, Gerald A.

149

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

SciTech Connect (OSTI)

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

Lynn M. Russell; Richard C.J. Somerville

2012-11-05T23:59:59.000Z

150

Understanding Brown Carbon Aerosols and Their Role in Climate Change  

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

Brown Carbon Aerosols Brown Carbon Aerosols Tiny aerosol particles in the atmosphere are a possible cause of climate change. Among the many contributors to climate change are aerosols in the atmosphere. These tiny particles suspended in the air come from many sources, some natural and some man-made. Some aerosols are organic (containing carbon), while others are inorganic (such as sea salt and sulfates). Most aerosols reflect sunlight, and some also absorb it. Many of these nanoparticles have severe health effects in addition to climate effects. Human activities that produce aerosols include transportation, industry, and agriculture. Black carbon particles (a component of soot) originating from combustion processes have been known for some time to absorb sunlight and warm the

151

Near real time vapor detection and enhancement using aerosol adsorption  

SciTech Connect (OSTI)

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.

Novick, Vincent J.; Johnson, Stanley A.

1997-12-01T23:59:59.000Z

152

Near real time vapor detection and enhancement using aerosol adsorption  

DOE Patents [OSTI]

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.

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

1999-08-03T23:59:59.000Z

153

Near real time vapor detection and enhancement using aerosol adsorption  

DOE Patents [OSTI]

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.

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

1999-01-01T23:59:59.000Z

154

Improved solid aerosol generator  

DOE Patents [OSTI]

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

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

1988-07-19T23:59:59.000Z

155

Interannual Tropospheric Aerosol Variability in the Late Twentieth Century and Its Impact on Tropical Atlantic and West African Climate by Direct and Semidirect Effects  

Science Journals Connector (OSTI)

A new high-resolution global tropospheric aerosol dataset with monthly resolution is generated using version 4 of the Community Atmosphere Model (CAM4) coupled to a bulk aerosol model and forced with recent estimates of surface emissions for the ...

Salil Mahajan; Katherine J. Evans; John E. Truesdale; James J. Hack; Jean-Franois Lamarque

2012-12-01T23:59:59.000Z

156

Spatially indirect excitons in coupled quantum wells  

SciTech Connect (OSTI)

Microscopic quantum phenomena such as interference or phase coherence between different quantum states are rarely manifest in macroscopic systems due to a lack of significant correlation between different states. An exciton system is one candidate for observation of possible quantum collective effects. In the dilute limit, excitons in semiconductors behave as bosons and are expected to undergo Bose-Einstein condensation (BEC) at a temperature several orders of magnitude higher than for atomic BEC because of their light mass. Furthermore, well-developed modern semiconductor technologies offer flexible manipulations of an exciton system. Realization of BEC in solid-state systems can thus provide new opportunities for macroscopic quantum coherence research. In semiconductor coupled quantum wells (CQW) under across-well static electric field, excitons exist as separately confined electron-hole pairs. These spatially indirect excitons exhibit a radiative recombination time much longer than their thermal relaxation time a unique feature in direct band gap semiconductor based structures. Their mutual repulsive dipole interaction further stabilizes the exciton system at low temperature and screens in-plane disorder more effectively. All these features make indirect excitons in CQW a promising system to search for quantum collective effects. Properties of indirect excitons in CQW have been analyzed and investigated extensively. The experimental results based on time-integrated or time-resolved spatially-resolved photoluminescence (PL) spectroscopy and imaging are reported in two categories. (i) Generic indirect exciton systems: general properties of indirect excitons such as the dependence of exciton energy and lifetime on electric fields and densities were examined. (ii) Quasi-two-dimensional confined exciton systems: highly statistically degenerate exciton systems containing more than tens of thousands of excitons within areas as small as (10 micrometer){sup 2} were observed. The spatial and energy distributions of optically active excitons were used as thermodynamic quantities to construct a phase diagram of the exciton system, demonstrating the existence of distinct phases. Optical and electrical properties of the CQW sample were examined thoroughly to provide deeper understanding of the formation mechanisms of these cold exciton systems. These insights offer new strategies for producing cold exciton systems, which may lead to opportunities for the realization of BEC in solid-state systems.

Lai, Chih-Wei Eddy

2004-03-01T23:59:59.000Z

157

ERROR ESTIMATIONS FOR INDIRECT MEASUREMENTS  

E-Print Network [OSTI]

Chapter 1 ERROR ESTIMATIONS FOR INDIRECT MEASUREMENTS: RANDOMIZED VS. DETERMINISTIC ALGORITHMS difficult or even impossible to directly measure the quantity in which we are interested: e.g., we cannot directly measure a distance to a distant galaxy or the amount of oil in a given well. Since we cannot

Kreinovich, Vladik

158

Performance improvement of direct- and indirect-fired heaters  

SciTech Connect (OSTI)

The operating performance of direct and indirect heaters is discussed, and principles and guidelines that can be applied to effect improvements in efficiency are presented. This paper also discusses the associated heater efficiencies and several useful operating techniques to approach the maximum, steady-state heater efficiency. The techniques presented apply to all types of direct-and indirect-fired heaters: salt bath heaters, propane vaporizers, heater/treaters, production heaters, and glycol and amine regenerators.

Sams, G.W.; Hunter, J.D.

1988-08-01T23:59:59.000Z

159

Heavy Duty Diesel Engine Exhaust Aerosol Particle and Ion Measurements  

Science Journals Connector (OSTI)

Heavy Duty Diesel Engine Exhaust Aerosol Particle and Ion Measurements ... diesel engines have received increasing attention due to their potential health effects. ...

Tero Lhde; Topi Rnkk; Annele Virtanen; Tanja J. Schuck; Liisa Pirjola; Kaarle Hmeri; Markku Kulmala; Frank Arnold; Dieter Rothe; Jorma Keskinen

2008-12-09T23:59:59.000Z

160

Raman Lidar Measurements of Aerosols and Water Vapor During the...  

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

modifications reduced but could not eliminate these adverse effects. The Raman lidar water vapor (aerosol extinction) measurements produced by these modified algorithms were,...

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


161

Capstone Depleted Uranium Aerosols: Generation and Characterization  

SciTech Connect (OSTI)

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.

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

162

Indirect liquefaction processes. Technical report  

SciTech Connect (OSTI)

This report examines the technology feasibility of the various coal gasification and indirect liquefaction technologies. Also included is the best-estimate costs for methanol and gasoline using the various technologies with three different coal/feedstocks by critically analyzing publicly available design studies and placing them on a common technical/financial basis. The following conclusion is that methanol from coal is cheaper than gasoline via either the Mobile MTG process or the Fisher/Tropsch process.

McGuckin, J.

1982-02-01T23:59:59.000Z

163

Effects of anthropogenic activities on the molecular composition of urban organic aerosols: an ultrahigh resolution mass spectrometry study  

E-Print Network [OSTI]

of Chemistry, Aarhus University, Aarhus, DK-8000, Denmark 11 4Department of Analytical Chemistry, Ghent University, Krijgslaan 281, S12, BE-9000 12 Ghent, Belgium 13 5Department of Pharmaceutical Sciences, University of Antwerp, Universiteitsplein 1, BE-14... ). 95 The objective of the current study is to apply nanoESI UHRMS to determine the molecular 96 composition of urban PM2.5 (particles with ?2.5m). Aerosol samples were collected at the 97 industrial site in Cork Ireland during summer with the aim...

Kourtchev, I.; O'Connor, I. P.; Giorio, C.; Fuller, S.; Kristenen, K.; Maenhaut, W.; Wenger, J. C.; Sodeau, J. R.; Glasius, M.; Kalberer, M.

2014-02-23T23:59:59.000Z

164

ARM - Measurement - Aerosol absorption  

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

absorption absorption ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Aerosol absorption The process in which radiation energy is retained by aerosols. Categories Aerosols Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments AOS : Aerosol Observing System CSPHOT : Cimel Sunphotometer IAP : In-situ Aerosol Profiles (Cessna Aerosol Flights) PSAP : Particle Soot Absorption Photometer PASS : Photoacoustic Soot Spectrometer External Instruments OMI : Ozone Monitoring Instrument

165

ARM - Measurement - Aerosol concentration  

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

concentration concentration ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Aerosol concentration A measure of the amount of aerosol particles (e.g. number, mass, volume) per unit volume of air. Categories Aerosols Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments AOS : Aerosol Observing System CSPHOT : Cimel Sunphotometer CPC : Condensation Particle Counter IAP : In-situ Aerosol Profiles (Cessna Aerosol Flights) TDMA : Tandem Differential Mobility Analyzer

166

Indirect Cost Sharing Policies and Guidelines  

E-Print Network [OSTI]

Indirect Cost Sharing Policies and Guidelines University at Albany In the 1997 Fall semester% of the University's indirect cost return to the schools or colleges, departments, and centers. The allocations are determined in direct proportion to the units' contribution toward the total indirect cost recovery pool

Kidd, William S. F.

167

Carbonaceous Aerosols and Radiative...  

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

and absorption of light by aerosols. At the ground sites, a new Humidigraph, a Cloud Condensation Nuclei Counter, a Scanning Mobility Particle Sizer, and an upgraded 915-MHz...

168

Investigation of the aerosol-cloud interaction using the WRF framework  

E-Print Network [OSTI]

In this dissertation, a two-moment bulk microphysical scheme with aerosol effects is developed and implemented into the Weather Research and Forecasting (WRF) model to investigate the aerosol-cloud interaction. Sensitivities of cloud properties...

Li, Guohui

2009-05-15T23:59:59.000Z

169

Composition and Reactions of Atmospheric Aerosol Particles  

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

Composition and Reactions of Composition and Reactions of Atmospheric Aerosol Particles Composition and Reactions of Atmospheric Aerosol Particles Print Wednesday, 29 June 2005 00:00 Microscopic aerosol particles in the atmosphere contain carbonaceous components from mineral dust and combustion emissions released from around the world. How long these tiny particles remain in the atmosphere can have a huge impact on the global climate. Measurements based on high-resolution scanning transmission x-ray images obtained at the ALS have revealed chemical reactions on and in atmospheric aerosol particles that caused particle growth while changing organic composition by 13 to 24% per day, an oxidation rate significantly slower than is currently used in atmospheric models. Since oxidation has a strong effect on particle lifetime in the atmosphere, these results will help climate scientists refine the computer models used to predict climate change.

170

Composition and Reactions of Atmospheric Aerosol Particles  

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

Composition and Reactions of Atmospheric Aerosol Particles Print Composition and Reactions of Atmospheric Aerosol Particles Print Microscopic aerosol particles in the atmosphere contain carbonaceous components from mineral dust and combustion emissions released from around the world. How long these tiny particles remain in the atmosphere can have a huge impact on the global climate. Measurements based on high-resolution scanning transmission x-ray images obtained at the ALS have revealed chemical reactions on and in atmospheric aerosol particles that caused particle growth while changing organic composition by 13 to 24% per day, an oxidation rate significantly slower than is currently used in atmospheric models. Since oxidation has a strong effect on particle lifetime in the atmosphere, these results will help climate scientists refine the computer models used to predict climate change.

171

Composition and Reactions of Atmospheric Aerosol Particles  

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

Composition and Reactions of Atmospheric Aerosol Particles Print Composition and Reactions of Atmospheric Aerosol Particles Print Microscopic aerosol particles in the atmosphere contain carbonaceous components from mineral dust and combustion emissions released from around the world. How long these tiny particles remain in the atmosphere can have a huge impact on the global climate. Measurements based on high-resolution scanning transmission x-ray images obtained at the ALS have revealed chemical reactions on and in atmospheric aerosol particles that caused particle growth while changing organic composition by 13 to 24% per day, an oxidation rate significantly slower than is currently used in atmospheric models. Since oxidation has a strong effect on particle lifetime in the atmosphere, these results will help climate scientists refine the computer models used to predict climate change.

172

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

SciTech Connect (OSTI)

We proposed a variety of tasks centered on the following question: what can we learn about 3D cloud-radiation processes and aerosol-cloud interaction from rapid-sampling ARM measurements of spectral zenith radiance? These ARM measurements offer spectacular new and largely unexploited capabilities in both the temporal and spectral domains. Unlike most other ARM instruments, which average over many seconds or take samples many seconds apart, the new spectral zenith radiance measurements are fast enough to resolve natural time scales of cloud change and cloud boundaries as well as the transition zone between cloudy and clear areas. In the case of the shortwave spectrometer, the measurements offer high time resolution and high spectral resolution, allowing new discovery-oriented science which we intend to pursue vigorously. Research objectives are, for convenience, grouped under three themes: ? Understand radiative signature of the transition zone between cloud-free and cloudy areas using data from ARM shortwave radiometers, which has major climatic consequences in both aerosol direct and indirect effect studies. ? Provide cloud property retrievals from the ARM sites and the ARM Mobile Facility for studies of aerosol-cloud interactions. ? Assess impact of 3D cloud structures on aerosol properties using passive and active remote sensing techniques from both ARM and satellite measurements.

Alexander Marshak; Warren Wiscombe; Yuri Knyazikhin; Christine Chiu

2011-05-24T23:59:59.000Z

173

CLOUD PHYSICS From aerosol-limited to invigoration  

E-Print Network [OSTI]

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

Napp, Nils

174

Climate impacts of carbonaceous and other non-sulfate aerosols: A proposed study  

SciTech Connect (OSTI)

In addition to sulfate aerosols, carbonaceous and other non-sulfate aerosols are potentially significant contributors to global climate change. We present evidence that strongly suggests that current assessments of the effects of aerosols on climate may be inadequate because major aerosol components, especially carbonaceous aerosols, are not included in these assessments. Although data on the properties and distributions of anthropogenic carbonaceous aerosols are insufficient to allow quantification of their climate impacts, the existing information suggests that climate forcing by this aerosol component may be significant and comparable to that by sulfate aerosols. We propose that a research program be undertaken to support a quantitative assessment of the role in climate forcing of non-sulfate, particularly carbonaceous, aerosols.

Andreae, M.O.; Crutzen, P.J. [Max Planck Institute for Chemistry, Mainz (Germany); Cofer, W.R. III; Hollande, J.M. [NASA Langley Research Center, Hampton, VA (United States). Atmospheric Sciences Division] [and others

1995-06-01T23:59:59.000Z

175

Direct Aerosol Forcing Uncertainty  

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

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.

Mccomiskey, Allison

176

BNL | Aerosol Lifecycle IOP  

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

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

177

Response of the NCAR Community Climate Model to the Radiative Forcing by the Naturally Occurring Tropospheric Aerosol  

Science Journals Connector (OSTI)

We insert the effect of naturally occurring tropospheric aerosols on solar radiation into the NCAR Community Climate Model (CCM). The effect of the aerosol depends on concentration and type (continental, maritime), surface albedo, solar zenith ...

James A. Coakley Jr.; Robert D. Cess

1985-08-01T23:59:59.000Z

178

Biomass Indirect Liquefaction Strategy Workshop: Summary Report...  

Broader source: Energy.gov (indexed) [DOE]

Strategy Workshop: Summary Report Biomass Indirect Liquefaction Strategy Workshop: Summary Report This report is based on the proceedings of the U.S. DOE's Bioenergy Technologies...

179

Biomass Indirect Liquefaction Strategy Workshop: Summary Report  

Broader source: Energy.gov [DOE]

This report is based on the proceedings of the U.S. DOEs Bioenergy Technologies Office Biomass Indirect Liquefaction Strategy Workshop.

180

Aerosol Cans? -Aerosol cans use a pressurized  

E-Print Network [OSTI]

? - The waste generated in the processing of images/photos contains silver. Silver is a toxic heavy metal the product. Propellants are often flammable and/or toxic. Therefore, never store aerosol cans near ignition of this pamphlet. -Carefully transfer the old paint thinner from the one gallon closable can to the 30 gallon metal

Jia, Songtao

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


181

ARM - Measurement - Aerosol particle size  

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

particle size particle size ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Aerosol particle size Linear size (e.g. radius or diameter) of an aerosol particle. Categories Aerosols Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. Field Campaign Instruments AEROSMASSSPEC : Aerosol Mass Spectrometer CPI : Cloud Particle Imager DRI-GND : Desert Research Institute Ground-Based Aerosol Instruments DRUM-AEROSOL : Drum Aerosol Sampler AEROSOL-TOWER-EML : EML Tower based Aerosol Measurements

182

Indirect Estimation of Radioactivity in Containerized Cargo  

SciTech Connect (OSTI)

Detecting illicit nuclear and radiological material in containerized cargo challenges the state of the art in detection systems. Current systems are being evaluated and new systems envisioned to address the need for the high probability of detection and extremely low false alarm rates necessary to thwart potential threats and extremely low nuisance and false alarm rates while maintaining necessary to maintain the flow of commerce impacted by the enormous volume of commodities imported in shipping containers. Maintaining flow of commerce also means that primary inspection must be rapid, requiring relatively indirect measurements of cargo from outside the containers. With increasing information content in such indirect measurements, it is natural to ask how the information might be combined to improved detection. Toward this end, we present an approach to estimating isotopic activity of naturally occurring radioactive material in cargo grouped by commodity type, combining container manifest data with radiography and gamma spectroscopy aligned to location along the container. The heart of this approach is our statistical model of gamma counts within peak regions of interest, which captures the effects of background suppression, counting noise, convolution of neighboring cargo contributions, and down-scattered photons to provide physically constrained estimates of counts due to decay of specific radioisotopes in cargo alone. Coupled to that model, we use a mechanistic model of self-attenuated radiation flux to estimate the isotopic activity within cargo, segmented by location within each container, that produces those counts. We demonstrate our approach by applying it to a set of measurements taken at the Port of Seattle in 2006. This approach to synthesizing disparate available data streams and extraction of cargo characteristics holds the potential to improve primary inspection using current detection capabilities and to enable simulation-based evaluation of new candidate detection systems.

Jarman, Kenneth D.; Scherrer, Chad; Smith, Eric L.; Chilton, Lawrence; Anderson, K. K.; Ressler, Jennifer J.; Trease, Lynn L.

2011-01-01T23:59:59.000Z

183

A World-wide Stratospheric Aerosol Layer  

Science Journals Connector (OSTI)

...Massachusetts An aerosol layer has been identified by a stratospheric balloon and aircraft aerosol collection program. Measurements...Abstract. An aerosol layer has been identified by a stratospheric balloon and aircraft aerosol collection program. Meas-urements...

Christian E. Junge; Charles W. Chagnon; James E. Manson

1961-05-12T23:59:59.000Z

184

Biofuels and indirect land use change  

E-Print Network [OSTI]

Biofuels and indirect land use change The case for mitigation October 2011 #12;About this study), Malaysian Palm Oil Board, National Farmers Union, Novozymes, Northeast Biofuels Collaborative, Patagonia Bio contributed views on a confidential basis. #12;1Biofuels and indirect land use change The case for mitigation

185

Inter-annual Tropospheric Aerosol Variability in Late Twentieth Century and its Impact on Tropical Atlantic and West African Climate by Direct and Semi-direct Effects  

SciTech Connect (OSTI)

A new high-resolution (0.9$^{\\circ}$x1.25$^{\\circ}$ in the horizontal) global tropospheric aerosol dataset with monthly resolution is generated using the finite-volume configuration of Community Atmosphere Model (CAM4) coupled to a bulk aerosol model and forced with recent estimates of surface emissions for the latter part of twentieth century. The surface emissions dataset is constructed from Coupled Model Inter-comparison Project (CMIP5) decadal-resolution surface emissions dataset to include REanalysis of TROpospheric chemical composition (RETRO) wildfire monthly emissions dataset. Experiments forced with the new tropospheric aerosol dataset and conducted using the spectral configuration of CAM4 with a T85 truncation (1.4$^{\\circ}$x1.4$^{\\circ}$) with prescribed twentieth century observed sea surface temperature, sea-ice and greenhouse gases reveal that variations in tropospheric aerosol levels can induce significant regional climate variability on the inter-annual timescales. Regression analyses over tropical Atlantic and Africa reveal that increasing dust aerosols can cool the North African landmass and shift convection southwards from West Africa into the Gulf of Guinea in the spring season in the simulations. Further, we find that increasing carbonaceous aerosols emanating from the southwestern African savannas can cool the region significantly and increase the marine stratocumulus cloud cover over the southeast tropical Atlantic ocean by aerosol-induced diabatic heating of the free troposphere above the low clouds. Experiments conducted with CAM4 coupled to a slab ocean model suggest that present day aerosols can shift the ITCZ southwards over the tropical Atlantic and can reduce the ocean mixed layer temperature beneath the increased marine stratocumulus clouds in the southeastern tropical Atlantic.

Evans, Katherine J [ORNL; Hack, James J [ORNL; Truesdale, John [National Center for Atmospheric Research (NCAR); Mahajan, Salil [ORNL; Lamarque, J-F [University Center for Atmospheric Research

2012-01-01T23:59:59.000Z

186

Development and Characterization of a Thermodenuder for Aerosol Volatility Measurements  

SciTech Connect (OSTI)

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

Dr. Timothy Onasch

2009-09-09T23:59:59.000Z

187

College of Engineering Request for Institutional Waiver of Indirect Cost  

E-Print Network [OSTI]

PAF Number College of Engineering Request for Institutional Waiver of Indirect Cost Principal Investigator Sponsor Project Title Total Direct Costs Total Modified Direct Costs Full Indirect Costs Rate Full Indirect Costs Amount Total Project Costs (with Full IDC) Requested Indirect Costs Rate Requested Indirect

Kamat, Vineet R.

188

Researchers Model Impact of Aerosols Over California  

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

Researchers Model Researchers Model Impact of Aerosols Over California Researchers Model Impact of Aerosols Over California Research may clarify the effectiveness of regional pollution controls May 28, 2013 | Tags: Climate Research, Hopper Contact: Linda Vu, lvu@lbl.gov, (510) 495-2404 LosAngelesSmogv1.jpg Smog over downtown Los Angeles. Aerosols are microscopic particles-like dust, pollen and soot-that ubiquitously float around in our atmosphere. Despite their tiny stature, these particles can have a huge impact on human health, climate and the environment. So scientists from the Pacific Northwest National Laboratory (PNNL), Colorado State University and the California Air Resources Board have set out to characterize the roles of various particles as atmospheric change agents on a regional scale.

189

Experiments related to the resuspension of aerosols during hydrogen burns  

SciTech Connect (OSTI)

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.

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

1987-01-01T23:59:59.000Z

190

Characterizing the formation of secondary organic aerosols  

SciTech Connect (OSTI)

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

Lunden, Melissa; Black, Douglas; Brown, Nancy

2004-02-01T23:59:59.000Z

191

Estimating diesel engine performance by indirect methods  

E-Print Network [OSTI]

was under taken with an instrumented John Deere 4440 tractor to investigate the feasibility of using indirect methods to measure engine power output and fuel consumption. Two indirectly related variables studied were exhaust gas temperature and injector... and assistance in the performance of research tasks. Steve Bandy and Costas Kotzabassis are also thanked for their contributions. The financial support of Deere 5 Company, the Center for Energy and Mineral Resources and the Texas Agricultural Experiment...

McKiernan, Michael

2012-06-07T23:59:59.000Z

192

Computational Fluid Dynamics Study of Aerosol Transport and Deposition Mechanisms  

E-Print Network [OSTI]

In this work, various aerosol particle transport and deposition mechanisms were studied through the computational fluid dynamics (CFD) modeling, including inertial impaction, gravitational effect, lift force, interception, and turbophoresis, within...

Tang, Yingjie

2012-07-16T23:59:59.000Z

193

Geometrical Optics of Dense Aerosols  

SciTech Connect (OSTI)

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

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

2013-04-24T23:59:59.000Z

194

Jankovic Aerosol Characterization.ppt  

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

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

195

Thermochemical Ethanol via Indirect Gasification and Mixed Alcohol...  

Energy Savers [EERE]

Ethanol via Indirect Gasification and Mixed Alcohol Synthesis of Lignocellulosic Biomass Thermochemical Ethanol via Indirect Gasification and Mixed Alcohol Synthesis of...

196

E-Print Network 3.0 - aerosol mass spectrometry Sample Search...  

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

used in health effects studies by aerosol mass spectrometry Wingen, L... and heats of sublimation using atmospheric solids analysis probe mass spectrometry (ASAP-MS) Bruns E......

197

E-Print Network 3.0 - atmospheric aerosol processes Sample Search...  

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

of Applied Science Collection: Environmental Sciences and Ecology 3 Arctic-Winter Climatology and Radiative Effects of Clouds and Aerosols Based on Lidar and Radar Measurements...

198

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

199

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

SciTech Connect (OSTI)

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

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

2009-02-01T23:59:59.000Z

200

THE EFFECTS OF FLAME TEMPERATURE, PARTICLE SIZE AND EUROPIUM DOPING CONCENTRATION ON THE PROPERTIES OF Y2O3:EU PARTICLES FORMED IN A FLAME AEROSOL PROCESS  

E-Print Network [OSTI]

ix LIST OF FIGURES FIGURE Page 1 Schematic of flame spray pyrolysis apparatus... 2 O 3 :Eu 9, 10 . A number of methods may be used to synthesize Y 2 O 3 :Eu particles, including colloidal methods 11-13 , combustion in fuel-oxidizer mixture 14 , evaporation? condensation 15, 16 , furnace spray pyrolysis 17 . Flame aerosol...

Yim, Hoon

2010-07-14T23:59:59.000Z

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


201

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

SciTech Connect (OSTI)

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

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

1993-03-01T23:59:59.000Z

202

A comprehensive techno-economical review of indirect solar desalination  

Science Journals Connector (OSTI)

Solar powered desalination has been the focus of great interest recently worldwide. In the past, majority of the experimental investigations focused on solar coupled thermally driven conventional desalination technologies such as Multi-Stage Flash (MSF) and Multi-Effect Distillation (MED). With the advancement in membrane technology and its advantages such as high Recovery Ratios (RR) and low specific energy requirements Reverse Osmosis (RO) desalination has gained popularity. Currently, 52% of the indirect solar desalination plants are RO based with MED and MSF having a 13% and 9% share respectively. Membrane Distillation (MD) based plants represent 16% of the total and have been a focus of recent research efforts. This paper aims to provide a comprehensive review of all the indirect solar desalination technologies along with plant specific technical details. Efforts assessing the economic feasibility and cost affecting parameters for each desalination technology are also reviewed.

Muhammad Tauha Ali; Hassan E.S. Fath; Peter R. Armstrong

2011-01-01T23:59:59.000Z

203

Theory of indirect exciton photoluminescence in elevated quantum trap  

Science Journals Connector (OSTI)

Abstract Inspired by an experiment of indirect excitons photoluminescence (PL) in elevated quantum trap (High et al., 2009), we theoretically investigate the energy relaxation and nonlinear interactions of indirect excitons in coupled quantum wells. It is shown that, when increasing the laser power, the intensity reversion of two PL peaks is due to the phonon necklace effect. In addition, we use a nonlinear Schrdinger equation including attractive two-body, repulsive three-body interactions and the excitation power dependence of energy distribution to understand the exciton states. This model gives a natural account for the PL blue shift with the increase of the excitation power. This study thus provides an alternative way to understand the underlying physics of the exciton dynamics in coupled potential wells.

C.S. Liu; T.F. Xu; Y.H. Liu; X.L. Jing

2014-01-01T23:59:59.000Z

204

MELCOR 1. 8. 1 assessment: LACE aerosol experiment LA4  

SciTech Connect (OSTI)

The MELCOR code has been used to simulate LACE aerosol experiment LA4. In this test, the behavior of single- and double-component, hygroscopic and nonhygroscopic, aerosols in a condensing environment was monitored. Results are compared to experimental data, and to CONTAIN calculations. Sensitivity studies have been done on time step effects and machine dependencies; thermal/hydraulic parameters such as condensation on heat structures and on pool surface, and radiation heat transfer; and aerosol parameters such as number of MAEROS components and sections assumed, the degree to which plated aerosols are washed off heat structures by condensate film draining, and the effect of non-default values for shape factors and diameter limits. 9 refs., 50 figs., 13 tabs.

Kmetyk, L.N.

1991-09-01T23:59:59.000Z

205

ADEPT. aerosol deposition in cylindrical pipes  

SciTech Connect (OSTI)

ADEPT calculates the deposition of aerosols in straight cylindrical pipes during turbulent air flow. Aerosol deposition is calculated in a time-dependent manner based on empirical correlations for turbulent flow in pipes. The calculated deposition during a single time interval is cumulative with that of previous time intervals and results in a decreasing inner diameter of the pipe. The calculated deposition is assumed uniform over the length of the pipe. The entering aerosol distribution is specified by the user in the form of a log-normal distribution of accumulated mass versus particle size and may be time dependent. Entering flow conditions are also specified by the user and may also be time dependent. For simplicity and generality, the geometry implicit in the program is that of a cylindrical pipe with no bends or fittings. The flow is turbulent and monodirectional; only one set of inlet conditions may be applied at a given time. The flow parameters are not calculated along the length of pipe; therefore, the dynamic behavior of the aerosol within the pipe as well as the effects of reentrainment cannot be determined explicitly. A typical problem requires 2 minutes of CPU time.

Fazekas, P.; Tewarson, S.C (Burns and Roe, Oradell, NJ (United States))

1985-01-01T23:59:59.000Z

206

ADEPT. Aerosol Deposition in Cylindrical Pipes  

SciTech Connect (OSTI)

ADEPT calculates the deposition of aerosols in straight cylindrical pipes during turbulent air flow. Aerosol deposition is calculated in a time-dependent manner based on empirical correlations for turbulent flow in pipes. The calculated deposition during a single time interval is cumulative with that of previous time intervals and results in a decreasing inner diameter of the pipe. The calculated deposition is assumed uniform over the length of the pipe. The entering aerosol distribution is specified by the user in the form of a log-normal distribution of accumulated mass versus particle size and may be time dependent. Entering flow conditions are also specified by the user and may also be time dependent. For simplicity and generality, the geometry implicit in the program is that of a cylindrical pipe with no bends or fittings. The flow is turbulent and monodirectional; only one set of inlet conditions may be applied at a given time. The flow parameters are not calculated along the length of pipe; therefore, the dynamic behavior of the aerosol within the pipe as well as the effects of reentrainment cannot be determined explicitly. A typical problem requires 2 minutes of CPU time.

Fazekas, P.; Tewarson, S.C [Burns and Roe, Oradell, NJ (United States)

1985-01-01T23:59:59.000Z

207

ARM - Mobile Aerosol Observing System  

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

FacilitiesMobile Aerosol Observing System FacilitiesMobile Aerosol Observing System AMF Information Science Architecture Baseline Instruments AMF1 AMF2 AMF3 Data Operations AMF Fact Sheet Images Contacts AMF Deployments Hyytiälä, Finland, 2014 Manacapuru, Brazil, 2014 Oliktok Point, Alaska, 2013 Los Angeles, California, to Honolulu, Hawaii, 2012 Cape Cod, Massachusetts, 2012 Gan Island, Maldives, 2011 Ganges Valley, India, 2011 Steamboat Springs, Colorado, 2010 Graciosa Island, Azores, 2009-2010 Shouxian, China, 2008 Black Forest, Germany, 2007 Niamey, Niger, 2006 Point Reyes, California, 2005 Mobile Aerosol Observing System Intensive aerosol observations conducted on the campus of Brookhaven National Laboratory on Long Island, New York, using the ARM Mobile Aerosol Observing System. Intensive aerosol observations conducted on the campus of Brookhaven

208

Aerosol Observing System (AOS) Handbook  

SciTech Connect (OSTI)

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

Jefferson, A

2011-01-17T23:59:59.000Z

209

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

E-Print Network [OSTI]

, New Mexico, USA Michael Mishchenko Goddard Institute for Space Studies, NASA, New York, New York, USA between t = 0.1 and t = 0.8. The Department of Energy research satellite instrument, the Multispectral [Hobbs et al., 1997]. The aerosols' direct effect involves their interaction with solar and terrestrial

210

Experimental study of nuclear workplace aerosol samplers  

E-Print Network [OSTI]

LITERATURE REVIEW Aerosol Losses in an Inlet . Aerosol Losses in a Transport System Aerosol Losses in CAMs Critical Flow Venturi 8 13 15 16 EXPERIMENT PROCEDURE 18 CAM Evaluation Consideration FAS Evaluation Consideration Test Protocol Mixing... Chamber Setup High Speed Aerosol Wind Tunnel Setup Low Speed Aerosol Wind Tunnel Setup Critical Flow Venturi 18 19 21 22 24 25 27 RESULTS AND DISCUSSION Page 28 Aerosol Penetration through Transport Systems and CAM Areal Uniformity Deposits...

Parulian, Antony

2012-06-07T23:59:59.000Z

211

Two-Column Aerosol Project  

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

help find the answer, the Department of Energy's Atmospheric Radiation Measurement (ARM) Climate Research Facility is conducting the Two-Column Aerosol Project (TCAP) at Cape Cod...

212

ARM Cloud Aerosol Precipitation Experiment  

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

Satellite Observation CAS Cloud Aerosol Spectrometer CCN Cloud Condensation Nuclei CIP Cloud Imaging Probe CPC Condensation Particle Counter CSPHOT Cimel sunphotometer CVI...

213

Indirect Utilization of Solar Energy [and Discussion  

Science Journals Connector (OSTI)

...research-article Indirect Utilization of Solar Energy [and Discussion] Hermann...a heat engine converting solar heat into the mechanical energy of wind, which in turn generates...readily be traced back to the solar input. Wind energy used to be a major source...

1980-01-01T23:59:59.000Z

214

Indirect costs of federally supported research  

Science Journals Connector (OSTI)

...research support that is largely for the financial advantage of the university. Third...present. An important basis for the cur-rent large differences between indirect cost...research program were provided through the assistance of W. F. Raub, associate director...

KT Brown

1981-04-24T23:59:59.000Z

215

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...

216

From spatially indirect excitons to momentum-space indirect excitons by an in-plane magnetic field  

Science Journals Connector (OSTI)

An in-plane magnetic field is found to change drastically the photoluminescence spectra and kinetics of interwell excitons in GaAs/AlxGa1-xAs coupled quantum wells. This effect is due to the in-plane magnetic-field-induced displacement of the interwell exciton dispersion in momentum space, which results in the transition from the momentum-space direct exciton ground state to the momentum-space indirect exciton ground state. An in-plane magnetic field is, therefore, an effective tool for exciton dispersion engineering.

L. V. Butov, A. V. Mintsev, Yu. E. Lozovik, K. L. Campman, and A. C. Gossard

2000-07-15T23:59:59.000Z

217

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

E-Print Network [OSTI]

quantity, but a radiation difference in the UV. Its main advantages are its insensitivity to scattering in climate physics today is the effect of aerosols on the global energy budget. The amount and sign of the effect of aerosols on the incoming solar radiation are unknown and produce a large uncertainty

Graaf, Martin de

218

Will black carbon mitigation dampen aerosol indirect forcing?1 W.-T. Chen1  

E-Print Network [OSTI]

.J. Adams3 , A. Nenes4 , and J.H. Seinfeld5,* 2 1 Jet Propulsion Laboratory, Pasadena, CA, USA3 2 Department carbonaceous sources (fossil fuel, domestic biofuel, and20 biomass burning) (termed HC). Radiative forcing

Nenes, Athanasios

219

Toward a new chemical mechanism in WRF/Chem for direct and indirect aerosol  

E-Print Network [OSTI]

, University of Colorado at Boulder, Boulder, Colorado, USA. 3 Earth System Research Laboratory, National Oceanic and Atmospheric administration, Boulder, Colorado, USA. e-mail: paolo to the coarse resolution of the inventory and by the missing of wildfire emissions. The modeled concentration

Curci, Gabriele

220

4, 58315854, 2004 Fluorescing aerosol  

E-Print Network [OSTI]

released by combustion into the atmosphere absorbs radiation and therefore heats the climate counteracting such as polycyclic aromatic hydrocarbons sticking to the aerosol particles, or bioaerosol such as bacteria, spores) or by combustion processes (soot), or they form in situ by gas to particle conversion, like sulphate aerosol. While

Paris-Sud XI, Université de

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


221

On modification of global warming by sulfate aerosols  

SciTech Connect (OSTI)

There is increasing evidence that the response of climate to increasing greenhouse gases may be modified by accompanying increases in sulfate aerosols. In this study, the patterns of response in the surface climatology of a coupled ocean-atmosphere general circulation model forced by increases in carbon dioxide alone is compared with those obtained by increasing carbon dioxide and aerosol forcing. The simulations are run from early industrial times using the estimated historical forcing and continued to the end of the twenty-first century assuming a nonintervention emissions scenario for greenhouse gases and aerosols. The comparison is made for the period 2030-2050 when the aerosol forcing is a maximum. In winter, the cooling due to aerosols merely tends to reduce the response to carbon dioxide, whereas in summer, it weakens the monsoon circulations and reverses some of the changes in the hydrological cycle on increasing carbon dioxide. This response is in some respects similar to that found in simulations with changed orbital parameters, as between today and the middle Holocene. The hydrological response in the palaeosimulations is supported by palaeoclimatic reconstructions. The results of changes in aerosol concentrations of the magnetic projected in the scenarios would have a major effect on regional climate, especially over Europe and Southeast Asia. 74 refs., 12 figs., 6 tabs.

Mitchell, J.F.B.; Johns, T.C. [Hadley Centre for Climate Prediction and Research, Berkshire (United Kingdom)] [Hadley Centre for Climate Prediction and Research, Berkshire (United Kingdom)

1997-02-01T23:59:59.000Z

222

Priorities for In-situ Aerosol Measurements  

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

Priorities for In-situ Priorities for In-situ Aerosol Measurements Parameters * Aerosol light absorption coefficient - spectral, including UV, vis, and IR - as f(RH), and at ambient RH * Phase function - or relevant integral properties (how many?) * Ice nuclei * Scattering vs. RH, for RH>90% * CCN, as f(S, D p ) * Size distribution * Chemical composition - for determining climate forcing, vs. radiative effect Calibration * Number concentration * Size and shape * Light absorption reference method Characterization * Accuracy and precision - need well-understood error bars * Algorithm comparisons * Closure studies * Facilities for method testing - aircraft time Methods * Inlets - shattering/splashing - location on airplane - passing efficiency - inletless analyzers/samplers * Packaging - modular/portable "pods" for multiple a/c

223

Aerosol Laboratory - Nuclear Engineering Division (Argonne)  

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

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

224

Association of asthma symptoms with peak particulate air pollution and effect modification by anti-inflammatory medication use.  

E-Print Network [OSTI]

respirable aerosol. Health Effects Institute Research Report38. Cambridge, MA:Health Effects Institute, 1990. Spektor

Delfino, Ralph J; Zeiger, Robert S; Seltzer, James M; Street, Donald H; McLaren, Christine E

2002-01-01T23:59:59.000Z

225

Research foundations: US private funder on indirect costs  

Science Journals Connector (OSTI)

... The JSMF, like many private foundations, considers it inappropriate for institutions to request indirect costs from ... foundations, considers it inappropriate for institutions to request indirect costs from private funders. In the United States, recovery of indirect costs by universities is negotiated with ...

Susan M. Fitzpatrick

2011-09-07T23:59:59.000Z

226

REQUEST FOR INDIRECT COST WAIVER I. Project Director  

E-Print Network [OSTI]

REQUEST FOR INDIRECT COST WAIVER I. Project Director: Department: Project Title: Project Sponsor without fully recovering the institutional indirect costs which will be incurred in conducting the project COSTS 1. FULL: OF I. A. C. 2. PARTIAL: OF H. B. K. TOTAL PROJECT COSTS L. INDIRECT COSTS TO BE WAIVED, J

Krovi, Venkat

227

SAGE II long-term measurements of stratospheric and upper tropospheric aerosols  

SciTech Connect (OSTI)

The Stratospheric Aerosol and Gas Experiment (SAGE) II solar occultation instrument has been making measurements on stratospheric aerosols and gases continually since October 1984. Observations from the SAGE II instrument provide a valuable long-term data set for study of the aerosol in the stratosphere and aerosol and cloud in the upper troposphere. The period of observation covers the decay phase of material injected by the El Chichon volcanic eruption in 1982, the years 1988--1990 when stratospheric aerosol levels approached background levels, and the period after the eruption of Mount Pinatubo in 1991. The Mount Pinatubo eruption caused the largest perturbation in stratospheric aerosol loading in this century, with effects on stratospheric dynamics and chemistry. The SAGE II data sequence shows the global dispersion of aerosols following the Mount Pinatubo eruption, as well as the changes occurring in stratospheric aerosol mass and surface area. The downward transfer of stratospheric aerosols into the upper troposphere following the earlier eruption of El Chichon is clearly visible. Estimates have been made of the amount of volcanic material lying in the upper troposphere and the way in which this varies with latitude and season.

Wang, P.H.; Kent, G.S. [Science and Technology Corp., Hampton, VA (United States); McCormick, M.P.; Thomason, L.W. [NASA Langley Research Center, Hampton, VA (United States). Atmospheric Sciences Div.

1995-12-31T23:59:59.000Z

228

ARM - Surface Aerosol Observing System  

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

FacilitiesSurface Aerosol Observing System FacilitiesSurface Aerosol Observing System AMF Information Science Architecture Baseline Instruments AMF1 AMF2 AMF3 Data Operations AMF Fact Sheet Images Contacts AMF Deployments Hyytiälä, Finland, 2014 Manacapuru, Brazil, 2014 Oliktok Point, Alaska, 2013 Los Angeles, California, to Honolulu, Hawaii, 2012 Cape Cod, Massachusetts, 2012 Gan Island, Maldives, 2011 Ganges Valley, India, 2011 Steamboat Springs, Colorado, 2010 Graciosa Island, Azores, 2009-2010 Shouxian, China, 2008 Black Forest, Germany, 2007 Niamey, Niger, 2006 Point Reyes, California, 2005 Surface Aerosol Observing System The ARM Mobile Facility (AMF) is equipped to quantify the interaction between clouds and aerosol particles. A counter-flow virtual impactor (CVI) is used to selectively sample cloud drops. The CVI takes advantage of the

229

Tankless Coil and Indirect Water Heaters | Department of Energy  

Broader source: Energy.gov (indexed) [DOE]

Tankless Coil and Indirect Water Heaters Tankless Coil and Indirect Water Heaters Tankless Coil and Indirect Water Heaters May 16, 2013 - 7:21pm Addthis An indirect water heater. An indirect water heater. How does it work? Tankless coil and indirect water heaters use your home's heating system to heat water. Tankless coil and indirect water heaters use a home's space heating system to heat water. They're part of what's called integrated or combination water and space heating systems. How They Work A tankless coil water heater provides hot water on demand without a tank. When a hot water faucet is turned on, water is heated as it flows through a heating coil or heat exchanger installed in a main furnace or boiler. Tankless coil water heaters are most efficient during cold months when the heating system is used regularly but can be an inefficient choice for many

230

Surface based remote sensing of aerosol-cloud interactions  

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

Surface based remote sensing of aerosol-cloud interactions Surface based remote sensing of aerosol-cloud interactions Feingold, Graham NOAA/Environmental Technology Laboratory Frisch, Shelby NOAA/Environmental Technology Laboratory Min, Qilong State University of New York at Albany Category: Cloud Properties We will present an analysis of the effect of aerosol on clouds at the Southern Great Plains ARM site. New methods for retrieving cloud droplet effective radius with radar (MMCR), multifilter rotating shadowband radiometer (MFRSR), and microwave radiometer (MWR) will be discussed. Relationships based on adiabatic clouds will be used to constrain retrievals. We will investigate the use of a range of proxies for cloud condensation nuclei, ranging from surface measurements of light scattering and accumulation mode number concentration, to lidar-measured extinction or

231

Strategies for advanced research in indirect liquefaction  

SciTech Connect (OSTI)

The 1992 Energy Policy Act laid the foundation for a more efficient, less vulnerable, and environmentally sustainable energy future for the United States. The goals of the Act include developing economically advanced technologies both for oil substitution through coal liquefaction and for production of chemicals and chemical intermediates from coal-derived synthesis gas. The development of alternative fuels from coal will provide the U.S. with improved long-term energy security and economic competitiveness. The Department of Energy (DOE), through its Liquid Fuels Program, has actively supported the development of alternative fuels and chemicals from domestic coal resources. Within the Liquid Fuels Program, the primary technologies being investigated are the direct and indirect liquefaction of coal. Indirect liquefaction technologies offer an alternative for converting coal to hydrocarbons and oxygenates that are environmentally acceptable in the transportation fuel market. Engineering analyses indicate that it may be possible to produce liquid products from coal at a cost competitive with crude oil in the near future.

Stiegel, G.J.; McGurl, G.V. [Pittsburgh Energy Technology Center, PA (United States); Srivastava, R.D.; Zhou, P. [Burns and Roe Services Corp., Pittsburgh, PA (United States)

1993-12-31T23:59:59.000Z

232

Nonlinear dynamics and inner-ring photoluminescence pattern of indirect excitons  

Science Journals Connector (OSTI)

We study the photoluminescence dynamics of ultracold indirect excitons optically created in a double-quantum-well heterostructure in the regime in which the inner photoluminescence ring is formed. We show that the spectrally resolved dynamics is in agreement with an excitonic origin for the inner ring which appears due to the local heating of indirect excitons by laser excitation. To confirm this interpretation and exclude the ionization of indirect excitons, we evaluate the excitonic density that is extracted from the energy of the photoluminescence emission. It is shown that optically injected carriers play a crucial role in that context as these are trapped in our field-effect device and then vary the electrostatic potential controlling the confinement of indirect excitons. This disruptive effect blurs the estimation of the exciton concentration. However, it is suppressed by placing the double quantum well behind a superlattice where a fraction of photoinjected carriers remains trapped and then screens fluctuations of the electrostatic potential at the gate electrodes. In this improved geometry, we then estimate that the exciton density remains one order of magnitude smaller than the critical density for the ionization of indirect excitons (or Mott transition) in the regime where the inner ring is formed.

Mathieu Alloing, Aristide Lematre, Elisabeth Galopin, and Franois Dubin

2012-06-07T23:59:59.000Z

233

Research Highlight  

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

the First Aerosol Indirect Effect in Shallow Cumuli Download a printable PDF Submitter: Berg, L., Pacific Northwest National Laboratory Area of Research: Aerosol Properties Working...

234

Antiviral therapy with small particle aerosols  

Science Journals Connector (OSTI)

The generation and use of small particle aqueous aerosols (1.23 m aerodynamic mass median diameter, GSD=2.0 m) containing ribavirin is described. Administered via aerosol, ribavirin will be deposited rather ...

V. Knight; B. Gilbert

1988-12-01T23:59:59.000Z

235

Sealing Ducts in Large Commercial Buildings with Aerosolized Sealant Particles  

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

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

236

E-Print Network 3.0 - airborne aerosol prediction Sample Search...  

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

profiles of aerosol extinction and optical depth Evaluate predictions from aerosol transport... aerosol measurements. Comparison of AOT ... Source: Brookhaven National...

237

Analysis of Langley optical depth data, with aerosol and gas retrievals,  

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

Analysis of Langley optical depth data, with aerosol and gas retrievals, Analysis of Langley optical depth data, with aerosol and gas retrievals, for the RSS 103 instrument in Barrow, Alaska Gianelli, Scott Columbia University - NASA/GISS Lacis, Andrew NASA/Goddard Institute for Space Studies Carlson, Barbara NASA/Goddard Institute for Space Studies Category: Aerosols Bimodal aerosol retrievals, and high-resolution retrevals of nitrogen dioxide, are performed on the Langley optical depth data from the RSS 103 device that was situated in Barrow, Alaska between March and August in 1999. The results show a higher fine mode aerosol optical depth on average than was retrieved by the RSS 102 at the SGP site. The seasonal cycle is also reversed with high values at Barrow occurring in the spring and low values in the summer. The fine mode effective radius also appears to

238

Measuring Aerosols Generated Inside Armoured Vehicles Perforated by Depleted Uranium Ammunition  

SciTech Connect (OSTI)

In response to questions raised after the Gulf War about the health significance of exposure to depleted uranium (DU), a study was initiated to provide an improved scientific basis for assessment of possible health effects of soldiers in vehicles struck by these munitions. As part of this experimental study, a series of DU penetrators were fired at an Abrams tank and a Bradley fighting vehicle, and the aerosols generated by vehicle perforation were collected and characterized. The aerosol sampling system designed for these tests consisted of filter cassettes, cascade impactors, a five-stage cyclone, and a moving filter. Aerosols collected were analyzed for uranium concentration and particle size distribution as a function of time. The aerosol samples were also analyzed for uranium oxide phases, particle morphology, and in vitro solubility. These data will provide input for use in future prospective and retrospective dose and health risk assessments of DU aerosols.

Parkhurst, MaryAnn

2003-01-01T23:59:59.000Z

239

The Uncertainty of Dosimetry of Radioactive and Non-Radiactive Aerosols  

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

The Uncertainty of Dosimetry of Radioactive and Non-Radiactive Aerosols The Uncertainty of Dosimetry of Radioactive and Non-Radiactive Aerosols Speaker(s): Lev Ruzer Date: September 27, 2001 - 12:00pm Location: Bldg. 90 Seminar Host/Point of Contact: David Faulkner Radioactive aerosols are a substantial risk factor in radiation safety in the atomic industry, mining industry, nuclear warhead depository and nuclear waste storage, as well as the natural radioactivity in houses. Assessment of the exposure, dose and health effect is very important for workers and the general population. In the last 5-10 years the problem of dosimetry of non-radioactive aerosols has become a "hot" topic in environmental health science with emphasis on submicron and even nanometer-sized particles. Both radioactive and non-radioactive aerosols

240

Corrosion aspects in indirect systems with secondary refrigerants.  

E-Print Network [OSTI]

?? Aqueous solutions of organic or inorganic salts are used as secondary refrigerants in indirect refrigeration systems to transport and transfer heat. Water is known (more)

Ignatowicz, Monika

2008-01-01T23:59:59.000Z

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


241

Massively Parallel Indirect Dielectrophoresis Controlled Placement of Carbon Nanotubes.  

E-Print Network [OSTI]

??Placement of single walled carbon nanotubes is demonstrated through massively parallel indirect dielectrophoresis (MPID). MPID is shown to be able to control the placement of (more)

Conley, Hiram Jacob

2009-01-01T23:59:59.000Z

242

2, 20952131, 2002 Below-cloud aerosol  

E-Print Network [OSTI]

). In addition, the understanding of wet removal processes remains crucial in local and regional pollutionACPD 2, 2095­2131, 2002 Below-cloud aerosol removal C. Andronache Title Page Abstract Introduction-cloud aerosol removal by rainfall for observed aerosol size distributions C. Andronache Boston College, Chestnut

Paris-Sud XI, Université de

243

6, 93519388, 2006 Aerosol-cloud  

E-Print Network [OSTI]

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

Paris-Sud XI, Université de

244

Aerosol collection characteristics of ambient aerosol samplers  

E-Print Network [OSTI]

the error for aniso- kinet1c sampl1ng with the smaller errors being associated w1th the larger orifices. For a higher accuracy in field sampling Watson suggested sampling with high volumetric rates and large sampling orifices to approximate isokinet1c..., was used to sample with a standard knife-edged orifice under isokinet1c conditions. May noted that the modified Casella cascade impactor was highly effective with sizes as small as about 1 um. Another excellent device for sampling down to 10 um...

Ortiz, Carlos A

2012-06-07T23:59:59.000Z

245

ARM - Measurement - Aerosol optical depth  

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

depth depth ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Aerosol optical depth A measure of how much light aerosols prevent from passing through a column of atmosphere. Categories Aerosols Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments HSRL : High Spectral Resolution Lidar MPL : Micropulse Lidar MFRSR : Multifilter Rotating Shadowband Radiometer NIMFR : Normal Incidence Multifilter Radiometer Field Campaign Instruments AOS-PMFOV : Acoustical Optical Spectrometer-Photometer with Multiple

246

ARM - Measurement - Aerosol optical properties  

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

properties properties ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Aerosol optical properties The optical properties of aerosols, including asymmetry factor, phase-function, single-scattering albedo, refractive index, and backscatter fraction. Categories Aerosols Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments CSPHOT : Cimel Sunphotometer NEPHELOMETER : Nephelometer Field Campaign Instruments AOS-PMFOV : Acoustical Optical Spectrometer-Photometer with Multiple

247

ARM - Measurement - Aerosol backscattered radiation  

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

backscattered radiation backscattered radiation ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Aerosol backscattered radiation The scattering of radiant energy into the hemisphere of space bounded by a plane normal to the direction of the incident radiation and lying on the same side as the incident ray. Categories Aerosols Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments AOS : Aerosol Observing System MPL : Micropulse Lidar NEPHELOMETER : Nephelometer

248

Quantifying the Hygroscopic Growth of Marine Boundary Layer Aerosols by Satellite-base and Buoy Observations  

Science Journals Connector (OSTI)

In this study, collocated satellite and buoy observations as well as satellite observations over an extended region during 2006-2010 were used to quantify the humidity effects on marine boundary layer (MBL) aerosols. Although the near-surface ...

Tao Luo; Renmin Yuan; Zhien Wang; Damao Zhang

249

Interaction of Ozone and Water Vapor with Spark Discharge Soot Aerosol Particles Coated with Benzo[a]pyrene:? O3 and H2O Adsorption, Benzo[a]pyrene Degradation, and Atmospheric Implications  

Science Journals Connector (OSTI)

Besides their relevance as toxic air pollutants, polycyclic aromatic compounds (PAC = PAH + derivatives) at the surface of combustion aerosol particles can influence these particles' interaction with reactive trace gases and water vapor, their activity as condensation nuclei, their atmospheric residence times, and consequently their direct and indirect climatic effects. ... Assuming equal relative losses of triphenylene and BaP during the clean up process, the triphenylene recovery, which was generally on the order of 70%, was used to correct the BaP peak area to 100% recovery. ... Thus, the potential influence of liquid organic or aqueous layers on atmospheric particles has to be kept in mind when using the kinetic parameters presented in this work for extrapolations to the atmosphere. ...

Ulrich Pschl; Thomas Letzel; Christian Schauer; Reinhard Niessner

2001-03-31T23:59:59.000Z

250

Indirect Cost THE ALBERT EINSTEIN COLLEGE OF MEDICINE OF  

E-Print Network [OSTI]

Indirect Cost THE ALBERT EINSTEIN COLLEGE OF MEDICINE OF YESHIVA UNIVERSITY ADMINISTRATIVE POLICY Policy No. 4.2 Facilities & Administrative Cost Rates for Grants and Contracts Issued By: Date Issued policy for the determination of Facilities & Administrative (indirect) cost (overhead) rates for all

Brown, Lucy L.

251

Review of models applicable to accident aerosols  

SciTech Connect (OSTI)

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.

Glissmeyer, J.A.

1983-07-01T23:59:59.000Z

252

New and Underutilized Technology: Multi-stage Indirect Evaporative Cooling  

Broader source: Energy.gov (indexed) [DOE]

Multi-stage Indirect Evaporative Multi-stage Indirect Evaporative Cooling New and Underutilized Technology: Multi-stage Indirect Evaporative Cooling October 4, 2013 - 4:33pm Addthis The following information outlines key deployment considerations for multi-stage evaporative cooling within the Federal sector. Benefits Multi-stage indirect evaporative cooling is an advanced evaporative cooler that can lower air temperatures without adding moisture. These systems evaporate water in a secondary (or working) airstream, which is discharged in multiple stages. No water or humidity is added to the primary (or product) airstream in the process. Application Multi-stage indirect evaporative cooling is applicable in office, research and development, service, and school applications. Climate and Regional Considerations

253

Tankless Coil and Indirect Water Heater Basics | Department of Energy  

Broader source: Energy.gov (indexed) [DOE]

Coil and Indirect Water Heater Basics Coil and Indirect Water Heater Basics Tankless Coil and Indirect Water Heater Basics August 19, 2013 - 3:03pm Addthis Illustration of a tankless coil water heater. The heater is box-shaped, and has two pipes sticking out one end: one a cold water inlet, and one a hot water outlet. These pipes lead into the heater to a cylindrical coil called a heat exchanger. Long tubes surrounding the heat exchanger are labeled the heated water jacket. At the bottom of the box is a row of small flames, called the boiler heat source. Tankless coil and indirect water heaters use a home or building's space heating system to heat water as part of an integrated or combination water and space heating system. How Tankless Coil and Indirect Water Heaters Work A tankless coil water heater uses a heating coil or heat exchanger

254

Sealing Ducts in Large Commercial Buildings with Aerosolized Sealant  

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

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

255

CARES Helps Explain Secondary Organic Aerosols  

ScienceCinema (OSTI)

What happens when urban man-made pollution mixes with what we think of as pristine forest air? To know more about what this interaction means for the climate, the Carbonaceous Aerosol and Radiative Effects Study, or CARES, field campaign was designed in 2010. The sampling strategy during CARES was coordinated with CalNex 2010, another major field campaign that was planned in California in 2010 by the California Air Resources Board (CARB), the National Oceanic and Atmospheric Administration (NOAA), and the California Energy Commission (CEC). "We found two things. When urban pollution mixes with forest pollutions we get more secondary organic aerosols," said Rahul Zaveri, FCSD scientist and project lead on CARES. "SOAs are thought to be formed primarily from forest emissions but only when they interact with urban emissions. The data is saying that there will be climate cooling over the central California valley because of these interactions." Knowledge gained from detailed analyses of data gathered during the CARES campaign, together with laboratory experiments, is being used to improve existing climate models.

Zaveri, Rahul

2014-06-02T23:59:59.000Z

256

Scientific analysis is essential to assess biofuel policy effects: in response to the paper by Kim and Dale on "Indirect land use change for biofuels: Testing predictions and improving analytical methodologies"  

SciTech Connect (OSTI)

Vigorous debate on the effects of biofuels derives largely from the changes in land use estimated using economic models designed mainly for the analysis of agricultural trade and markets. The models referenced for land-use change (LUC) analysis in the U.S. Environmental Protection Agency Final Rule on the Renewable Fuel Standard include GTAP, FAPRI-CARD, and FASOM. To address bioenergy impacts, these models were expanded and modified to facilitate simulations of hypothesized LUC. However, even when models use similar basic assumptions and data, the range of LUC results can vary by ten-fold or more. While the market dynamics simulated in these models include processes that are important in estimating effects of biofuel policies, the models have not been validated for estimating land-use changes and employ crucial assumptions and simplifications that contradict empirical evidence.

Kline, Keith L [ORNL] [ORNL; Oladosu, Gbadebo A [ORNL] [ORNL; Dale, Virginia H [ORNL] [ORNL; McBride, Allen [ORNL] [ORNL

2011-01-01T23:59:59.000Z

257

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

ScienceCinema (OSTI)

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.

None

2014-06-03T23:59:59.000Z

258

Indirect thermal liquefaction process for producing liquid fuels from biomass  

SciTech Connect (OSTI)

A progress report on an indirect liquefaction process to convert biomass type materials to quality liquid hydrocarbon fuels by gasification followed by catalytic liquid fuels synthesis has been presented. A wide variety of feedstocks can be processed through the gasification system to a gas with a heating value of 500 + Btu/SCF. Some feedstocks are more attractive than others with regard to producing a high olefin content. This appears to be related to hydrocarbon content of the material. The H/sub 2//CO ratio can be manipulated over a wide range in the gasification system with steam addition. Some feedstocks require the aid of a water-gas shift catalyst while others appear to exhibit an auto-catalytic effect to achieve the conversion. H/sub 2/S content (beyond the gasification system wet scrubber) is negligible for the feedstocks surveyed. The water gas shift reaction appears to be enhanced with an increase in pyrolysis reactor temperature over the range of 1300 to 1700/sup 0/F. Reactor temperature in the Fischer-Tropsch step is a significant factor with regard to manipulating product composition analysis. The optimum temperature however will probably correspond to maximum conversion to liquid hydrocarbons in the C/sub 5/ - C/sub 17/ range. Continuing research includes integrated system performance assessment, alternative feedstock characterization (through gasification) and factor studies for gasification (e.g., catalyst usage, alternate heat transfer media, steam usage, recycle effects, residence time study) and liquefaction (e.g., improved catalysts, catalyst activity characterization).

Kuester, J.L.

1980-01-01T23:59:59.000Z

259

ARM - PI Product - Direct Aerosol Forcing Uncertainty  

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

ProductsDirect Aerosol Forcing Uncertainty ProductsDirect Aerosol Forcing Uncertainty Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send PI Product : Direct Aerosol Forcing Uncertainty Site(s) NSA SGP TWP General Description Understanding sources of uncertainty in aerosol direct radiative forcing (DRF), the difference in a given radiative flux component with and without aerosol, is essential to quantifying changes in Earth's radiation budget. We examine the uncertainty in DRF due to measurement uncertainty in the quantities on which it depends: aerosol optical depth, single scattering albedo, asymmetry parameter, solar geometry, and surface albedo. Direct radiative forcing at the top of the atmosphere and at the surface as well as sensitivities, the changes in DRF in response to unit changes in

260

Purely Gasdynamic Multidimensional Indirect Detonation Initiation Using Localized Acoustic  

E-Print Network [OSTI]

Purely Gasdynamic Multidimensional Indirect Detonation Initiation Using Localized Acoustic detonation initiation process is presented that can be independent of diffusion, viscosity and turbulence to accelerate detonation formation. It is shown that given sufficient resolution, the detonation formation time

Vasilyev, Oleg V.

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


261

Indirect suppression of photosynthesis on individual leaves by arthropod herbivory  

E-Print Network [OSTI]

REVIEW Indirect suppression of photosynthesis on individual leaves by arthropod herbivory Paul D imaging tech- nologies revealed that alterations to photosynthesis and transpiration propagate of herbivory on photosynthesis, measured by gas exchange or chlorophyll fluorescence, and identifies four

DeLucia, Evan H.

262

Indirect Suppression of Photosynthesis on Individual Leaves by Arthropod Herbivory  

E-Print Network [OSTI]

REVIEW Indirect Suppression of Photosynthesis on Individual Leaves by Arthropod Herbivory PAUL D tissues are unaltered, and plant photosynthesis and water balance function normally. However, recent application of thermal and fluorescent imaging technologies revealed that alterations to photosynthesis

DeLucia, Evan H.

263

Carbonaceous Aerosol Study Using Advanced Particle Instrumentation  

E-Print Network [OSTI]

particles from the combustion of biomass fuels. Environ.range transport of biomass combustion aerosols. Environ.during the open combustion of biomass in the laboratory, J.

Qi, Li

2010-01-01T23:59:59.000Z

264

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...

265

The Two-Column Aerosol Project Definitions TCAP Educational  

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

What's the big deal about aerosols? The Two-Column Aerosol Project Definitions TCAP Educational Outreach Activity About ARM: The Atmospheric Radiation Measurement (ARM) Climate...

266

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...

267

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

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

properties of orographically induced clouds and how do these depend on dynamics, thermodynamics, and aerosol microphysics? * What is the role of aerosols and changing cloud...

268

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...

269

Optical, physical, and chemical properties of springtime aerosol...  

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

Optical, physical, and chemical properties of springtime aerosol over Barrow Alaska in 2008. Optical, physical, and chemical properties of springtime aerosol over Barrow Alaska in...

270

Final Report, DOE grant DE-FG02-99ER45780, "Indirect Excitons in Coupled Quantum Wells"  

SciTech Connect (OSTI)

The is the final technical report for this project, which was funded by the DOE from 1999 to 2012. The project focused on experimental studies of spatially indirect excitons in coupled quantum wells, with the aim of understanding the quantum physics of these particles, including such effects as pattern formation due to electron-hole charge separation, the Mott plasma-insulator transition, luminescence up-conversion through field-assisted tunneling, luminescence line shifts due to many-body renormalization and magnetic field effects on tunneling, and proposed effects such as Bose-Einstein condensation of indirect excitons and phase separation of bright and dark indirect excitons. Significant results are summarized here and the relation to other work is discussed.

Snoke, david W. [University of Pittsburgh

2014-07-21T23:59:59.000Z

271

Aerosol-Based Duct Sealing Technology  

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

8 8 Aerosol-Based Duct Sealing Technology During the past five years, research has quantified the impacts of residential duct system leakage on HVAC energy consumption and peak electricity demand. A typical house with ducts located in the attic or crawlspace wastes approximately 20% of heating and cooling energy through duct leaks and draws approximately 0.5 KW more electricity during peak cooling periods. A 1991 study indicated that sealing leaks could save close to one Quadrillion Btus per year. (see also Commercializing a New Technology) Because the major cost of sealing leaks in existing air distribution systems is the labor for the location and sealing process, reducing the labor could greatly improve the cost-effectiveness of such a retrofit. Field studies of duct sealing programs performed by HVAC contractors show

272

Aerosol nucleation in coal-fired power-plant plumes  

Science Journals Connector (OSTI)

New-particle nucleation within coal-fired power-plant plumes can have large effects on particle number concentrations particularly near source regions with implications for human health and climate. In order to resolve the formation and growth of particles in these plumes we have integrated TwO-Moment Aerosol Sectional (TOMAS) microphysics in the System for Atmospheric Modelling (SAM) a large-eddy simulation/cloud-resolving model (LES/CRM). We have evaluated this model against aircraft observations for three case studies and the model reproduces well the major features of each case. Using this model we have shown that meteorology and background aerosol concentrations can have strong effects on new-particle formation and growth in coal-fired power-plant plumes even if emissions are held constant. We subsequently used the model to evaluate the effects of SO 2 and NOx pollution controls on newparticle formation in coal-fired power-plant plumes. We found that strong reductions in NOx emissions without concurrent reductions in SO 2 emissions may increase new-particle formation due to increases in OH formation within the plume. We predicted the change in new-particle formation due to changes in emissions between 1997 and 2010 for 330 coal-fired power plants in the US and we found a median decrease of 19% in new-particle formation. However the magnitude and sign of the aerosol changes depend greatly on the relative reductions in NOx and SO 2 emissions in each plant. More extensive plume measurements for a range of emissions of SO 2 and NOx and in varying background aerosol conditions are needed however to better quantify these effects.

2013-01-01T23:59:59.000Z

273

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

SciTech Connect (OSTI)

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

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

2011-12-02T23:59:59.000Z

274

Modeling Heterogeneity in Indirect Effects: Multilevel Structural Equation Modeling Strategies  

E-Print Network [OSTI]

The heterogeneity implicit in much of social science research can be accommodated by using complex modeling procedures such as SEM or MLM. Ignoring heterogeneity, particularly with regard to nested data structures, can have serious consequences...

Fall, Emily C.

2011-12-31T23:59:59.000Z

275

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

E-Print Network [OSTI]

, heterogeneous surface reactions, cloud processing, and gas-to-particle partitioning through the formation of secondary organic aerosol (SOA) by organic gases (Pankow 1994). Moreover, SOA has been linked to adverse health effects as they typically contain... 1985; Ng et al. 2006; Presto et al. 2005; Saathoff et al. 2003). Such classes include cycloalkenes, aromatic hydrocarbons, and terpenes, most of which are cyclic compounds. When these compounds undergo atmospheric oxidation, 3 they produce first-generation...

Glen, Crystal

2012-02-14T23:59:59.000Z

276

BNL | Mobile Aerosol Observing System (MAOS)  

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

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

277

The Opposed Migration Aerosol Classifier (OMAC)  

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

The Opposed Migration Aerosol Classifier (OMAC) The Opposed Migration Aerosol Classifier (OMAC) Speaker(s): Harmony Gates Date: February 22, 2007 - 12:00pm Location: 90-4133 Seminar Host/Point of Contact: Melissa Lunden A new differential mobility classifier will be described. The instrument classifies aerosol particles in a channel flow between porous (or screen) electrodes. The aerosol enters the channel parallel to the porous electrodes, while a larger, particle-free cross-flow enters through one of the porous electrode. A potential difference between electrodes causes the charged aerosol particles to migrate upstream against the cross-flow. Only particles whose upward migration velocity balances the cross flow will be transmitted along the path of the classifier. Simulations of the OMAC show that it should give the same resolution at the traditional

278

Biobriefcase electrostatic aerosol collector  

DOE Patents [OSTI]

A system for sampling air and collecting particles entrained in the air comprising a receiving surface, a liquid input that directs liquid to the receiving surface and produces a liquid surface, an air input that directs the air so that the air with particles entrained in the air impact the liquid surface, and an electrostatic contact connected to the liquid that imparts an electric charge to the liquid. The particles potentially including bioagents become captured in the liquid by the air with particles entrained in the air impacting the liquid surface. Collection efficiency is improved by the electrostatic contact electrically charging the liquid. The effects of impaction and adhesion due to electrically charging the liquid allows a unique combination in a particle capture medium that has a low fluid consumption rate while maintaining high efficiency.

Bell, Perry M. (Tracy, CA); Christian, Allen T. (Madison, WI); Bailey, Christopher G. (Pleasanton, CA); Willis, Ladona (Manteca, CA); Masquelier, Donald A. (Tracy, CA); Nasarabadi, Shanavaz L. (Livermore, CA)

2009-03-17T23:59:59.000Z

279

Questions and Answers - What is one example of indirect evidence that  

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

How do I make amodel of an atom? How do I make a<br>model of an atom? Previous Question (How do I make a model of an atom?) Questions and Answers Main Index Next Question (What is an element? How many elements are there?) What is an element? Howmany elements are there? What is one example of indirect evidence that scientists use to study an atom? Pretty much everything we know about atoms is indirect evidence. One can't really see atoms. We do see enough of their effects that we can, with confidence, describe the nature of atoms. Here at Jefferson Lab we have quite a few instruments to measure the properties and behavior of atoms. We use a few simple tricks to measure atoms. The most common method is to shoot the atoms through an easy-to-ionize gas or liquid. Argon is the most

280

Global observations of desert dust and biomass burning aerosols  

E-Print Network [OSTI]

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

Graaf, Martin de

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


281

Lidar Investigation of Tropical Nocturnal Boundary Layer Aerosols and Cloud Macrophysics  

SciTech Connect (OSTI)

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

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

2013-10-01T23:59:59.000Z

282

Flex power perspectives of indirect power system control through dynamic  

Open Energy Info (EERE)

Flex power perspectives of indirect power system control through dynamic Flex power perspectives of indirect power system control through dynamic power price (Smart Grid Project) Jump to: navigation, search Project Name Flex power perspectives of indirect power system control through dynamic power price Country Denmark Coordinates 56.26392°, 9.501785° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":56.26392,"lon":9.501785,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

283

Improved direct and indirect systems of columns for ternary distillation  

SciTech Connect (OSTI)

Separation of a ternary mixture into almost pure components is discussed. Systems of distillation columns, with higher thermodynamic efficiency, are developed from a direct sequence (or indirect sequence) of distillation columns by allowing for two interconnecting streams of the same composition and different enthalpy. This increases the reversibility of distillation in the second column, which results in replacing a portion of the high-temperature boiling duty with a lower-temperature heat in the direct split case. For the indirect split case, the improvement allows a portion of the low-temperature condensing duty to be replaced with a higher-temperature condensation.

Agrawal, R.; Fidkowski, Z.T. [Air Products and Chemicals, Inc., Allentown, PA (United States)] [Air Products and Chemicals, Inc., Allentown, PA (United States)

1998-04-01T23:59:59.000Z

284

Studying trends in biomass burning aerosol using the Absorbing Aerosol Index derived from GOME, SCIAMACHY, and GOME-2  

E-Print Network [OSTI]

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

Tilstra, Gijsbert

285

E-Print Network 3.0 - aerosol chemical composition Sample Search...  

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

Aerosol on Clouds Summary: chemical composition and mixing stateTime-Resolved Aerosol Collector CCSEMEDX (ASP) Single particle... Sizer CCN spectrum Aerosol absorptionDRI...

286

E-Print Network 3.0 - aerosol number distributions Sample Search...  

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

inorganic composition PILS-IC Summary: 3563 nephelometers Aerosol number concentration CNC (TSI 3010, 3025) Aerosol size distribution DMA... and APS Non-volatile aerosol size...

287

E-Print Network 3.0 - aerosol jet system Sample Search Results  

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

-controlled laminar aerosol jets and their application for studying aerosol combustion processes Author(s): Shoshin Y... 2002 Times Cited: 6 48. Title: Exhaust aerosol of a...

288

CAS Indirect Cost Recovery Practices "Facilities and Administration" (F&A) Costs or, "Indirect Cost Recovery (ICR)," are costs incurred by the  

E-Print Network [OSTI]

CAS Indirect Cost Recovery Practices "Facilities and Administration" (F&A) Costs or, "Indirect Cost Recovery (ICR)," are costs incurred by the University for common or joint projects and cannot be specifically attributed to an individual project. Some examples of indirect costs include accounting staff

Vonessen, Nikolaus

289

Solar Physics (2004) 224: 34 C Springer 2005 The topical issue of "Space Climate: Direct and Indirect Observations of  

E-Print Network [OSTI]

Solar Physics (2004) 224: 3­4 C Springer 2005 PREFACE The topical issue of "Space Climate: Direct and Indirect Observations of Long-Term Solar Activity" is based on contributions presented at the First of solar activity, and their effects in the near-Earth environment and technoculture. As an analogy

Usoskin, Ilya G.

290

Aging Enhances Indirect Flight Muscle Fiber Performance yet Decreases Flight Ability in Drosophila  

SciTech Connect (OSTI)

We investigated the effects of aging on Drosophila melanogaster indirect flight muscle from the whole organism to the actomyosin cross-bridge. Median-aged (49-day-old) flies were flight impaired, had normal myofilament number and packing, barely longer sarcomeres, and slight mitochondrial deterioration compared with young (3-day-old) flies. Old (56-day-old) flies were unable to beat their wings, had deteriorated ultrastructure with severe mitochondrial damage, and their skinned fibers failed to activate with calcium. Small-amplitude sinusoidal length perturbation analysis showed median-aged indirect flight muscle fibers developed greater than twice the isometric force and power output of young fibers, yet cross-bridge kinetics were similar. Large increases in elastic and viscous moduli amplitude under active, passive, and rigor conditions suggest that median-aged fibers become stiffer longitudinally. Small-angle x-ray diffraction indicates that myosin heads move increasingly toward the thin filament with age, accounting for the increased transverse stiffness via cross-bridge formation. We propose that the observed protein composition changes in the connecting filaments, which anchor the thick filaments to the Z-disk, produce compensatory increases in longitudinal stiffness, isometric tension, power and actomyosin interaction in aging indirect flight muscle. We also speculate that a lack of MgATP due to damaged mitochondria accounts for the decreased flight performance.

Miller, Mark S.; Lekkas, Panagiotis; Braddock, Joan M.; Farman, Gerrie P.; Ballif, Bryan A.; Irving, Thomas C.; Maughan, David W.; Vigoreaux, Jim O. (IIT); (Vermont)

2008-10-02T23:59:59.000Z

291

PARAGON - An Integrated Approach for Characterizing Aerosol Climate Impacts and Environmental Interactions  

SciTech Connect (OSTI)

Aerosols exert myriad influences on the Earth?s environment and climate and on human health. The complexity of aerosol-related processes requires that information gathered to improve our understanding of climate change must originate from multiple sources, and that effective strategies for data integration need to be established. Currently, the aerosol community lacks the necessary tools and infrastructure to reap maximum scientific benefit from a vast array of observed and modeled data. Spatial and temporal sampling differences among a diverse set of sensors, nonuniform data qualities, aerosol mesoscale variabilities, and difficulties in separating cloud effects are some of the challenges that need to be addressed. A sustained, long-term program also requires maintaining consistently well-understood accuracies as measurement approaches evolve and improve. Achieving a comprehensive understanding of how aerosol physical, chemical, and radiative processes impact the Earth system can only be achieved through a multidisciplinary, interagency, and international initiative capable of dealing with these issues. A systematic approach, capitalizing on modern measurement and modeling techniques, geospatial statistics methodologies, and high-performance information technologies can provide the necessary machinery to support this objective. We outline a framework for integrating and interpreting observations and models and establishing an accurate, consistent and cohesive long-term record, following a strategy whereby information and tools of progressively greater sophistication are incorporated as problems of increasing complexity are tackled. This concept is named the Progressive Aerosol Retrieval and Assimilation Global Observing Network (PARAGON). To encompass the breadth of effort required, we present a set of recommendations dealing with data interoperability, integration, synergy, summarization and mining, model evaluation, calibration and validation, augmentation of surface and in situ measurements, advances in passive and active remote sensing, and design of satellite missions. Without an initiative of this nature, the scientific and policy communities will continue to struggle with understanding the quantitative impact of complex aerosol processes on regional and global climate change and air quality.

Diner, David J.; Ackerman, Thomas P.; Anderson, Theodore L.; Bosenberg, Jens; Braverman, Amy J.; Charlson, Robert J.; Collins, William D.; Davies, Roger; Holben, B. N.; Hostetler, Chris A.; Kahn, Ralph A.; Martonchik, John V.; Menzies, Robert T.; Miller, Mark A.; Ogren, J. A.; Penner, Joyce E.; Rasch, P; Schwartz, Stephen E.; Seinfeld, John H.; Stephens, Graeme L.; Torres, Omar; Travis, Larry D.; Wielicki, Bruce A.; Yu, Bin

2004-10-01T23:59:59.000Z

292

Spectro-Microscopic Measurements of Carbonaceous Aerosol Aging in Central California  

SciTech Connect (OSTI)

Carbonaceous aerosols are responsible for large uncertainties in climate models, degraded visibility, and adverse health effects. The Carbonaceous Aerosols and Radiative Effects Study (CARES) was designed to study carbonaceous aerosols in the natural environment of Central Valley, California, and learn more about their atmospheric formation and aging. This paper presents results from spectro-microscopic measurements of carbonaceous particles collected during CARES at the time of pollution accumulation event (June 27-29, 2010), when in situ measurements indicated an increase in the organic carbon content of aerosols as the Sacramento urban plume aged. Computer controlled scanning electron microscopy coupled with an energy dispersive X-ray detector (CCSEM/EDX) and scanning transmission X-ray microscopy coupled with near edge X-ray absorption spectroscopy (STXM/NEXAFS) were used to probe the chemical composition and morphology of individual particles. It was found that the mass of organic carbon on individual particles increased through condensation of secondary organic aerosol. STXM/NEXAFS indicated that the number fraction of homogenous organic particles lacking inorganic inclusions (greater than ~50 nm diameter) increased with plume age as did the organic mass per particle. Comparison of the CARES spectro-microscopic data set with a similar dataset obtained in Mexico City during the MILAGRO campaign showed that individual particles in Mexico City contained twice as much carbon as those sampled during CARES. The number fraction of soot particles at the Mexico City urban site (30%) was larger than at the CARES urban site (10%) and the most aged samples from CARES contained less carbon-carbon double bonds. Differences between carbonaceous particles in Mexico City and California result from different sources, photochemical conditions, gas phase reactants, and secondary organic aerosol precursors. The detailed results provided by these spectro-microscopic measurements will allow for a comprehensive evaluation of aerosol process models used in climate research.

Moffet, Ryan C.; Rodel, Tobias; Kelly, Stephen T.; Yu, Xiao-Ying; Carroll, Gregory; Fast, Jerome D.; Zaveri, Rahul A.; Laskin, Alexander; Gilles, Mary K.

2013-10-29T23:59:59.000Z

293

Southern hemisphere tropospheric aerosol microphysics  

SciTech Connect (OSTI)

Aerosol particle size distribution data have been obtained in the southern hemisphere from approximately 4{degree}S to 44{degree}S and between ground level and 6 km, in the vicinity of eastern Australia. The relative shape of the free-tropospheric size distribution for particles with radii larger than approximately 0.04 {mu}m was found to be remarkably stable with time, altitude, and location for the autumn-winter periods considered. This was despite some large concentration changes which were found to be typical of the southeastern Australian coastal region. The majority of free-troposphere large particles were found to have sulfuric acid or lightly ammoniated sulfate morphology. Large particles in the boundary layer almost exclusively had a sea-salt morphology.

Gras, J.L. (Commonwealth Scientific and Industrial Research Organization, Aspendale (Australia))

1991-03-20T23:59:59.000Z

294

ARM - Measurement - Aerosol particle size distribution  

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

particle size distribution particle size distribution ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Aerosol particle size distribution The number of aerosol particles present in any given volume of air within a specificied size range Categories Aerosols Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments SMPS : Scanning mobility particle sizer TDMA : Tandem Differential Mobility Analyzer UHSAS : Ultra-High Sensitivity Aerosol Spectrometer Field Campaign Instruments

295

BNL | Two-Column Aerosol Program (TCAP)  

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

Two-Column Aerosol Project (TCAP) Two-Column Aerosol Project (TCAP) There remain many key knowledge gaps despite advances in the scientific understanding of how aerosols and clouds evolve and affect climate. Many climatically important processes depend on particles that undergo continuous changes within a size range spanning a few nanometers to a few microns, and with compositions that consist of a variety of carbonaceous materials, soluble inorganic salts and acids and insoluble mineral dust. Primary particles, which are externally-mixed when emitted, are subject to coagulation and chemical changes associated with the condensation of semi-volatile gases to their surface resulting in a spectrum of compositions or mixing-states with a range of climate-affecting optical and hygroscopic properties. The numerical treatments of aerosol transformation

296

NASA's Aerosol-Cloud-Ecosystems (ACE) Mission  

Science Journals Connector (OSTI)

Plans for NASAs Aerosol-Cloud-Ecosystem (ACE) mission is described. Recommended by Earth Science Decadal Survey in 2007, ACE is nominally planned for a 2021 launch. ACE is...

Starr, David O'C

297

Aerosol Best Estimate Value-Added Product  

SciTech Connect (OSTI)

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.

Flynn, C; Turner, D; Koontz, A; Chand, D; Sivaraman, C

2012-07-19T23:59:59.000Z

298

ARM - Field Campaign - Aerosol Life Cycle IOP at BNL  

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

govCampaignsAerosol Life Cycle IOP at BNL govCampaignsAerosol Life Cycle IOP at BNL Campaign Links Images Wiki 2011 ASR STM Presentation: Sedlacek 2011 ASR STM Presentation: Springston 2010 ASR Fall Meeting: Sedlacek News, June 14, 2011: Next-generation Aerosol-sampling Stations to Head for India Related Campaigns Aerosol Life Cycle: Chemical Ionization Mass Spectrometer - CIMS 2011.07.10, Lee, OSC Aerosol Life Cycle: HR-ToF-AMS 2011.06.15, Zhang, OSC Aerosol Life Cycle: ARM Mobile Facility 2 Aerosol Observing System 2011.06.15, Sedlacek, OSC Aerosol Life Cycle: UV-APS and Nano-SMPS 2011.06.10, Hallar, OSC Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Aerosol Life Cycle IOP at BNL 2011.06.01 - 2011.08.31 Lead Scientist : Arthur Sedlacek For data sets, see below.

299

DETERMINATION OF RADIAL MOMENTS OF AN AEROSOL  

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

DETERMINATION OF RADIAL MOMENTS OF AN AEROSOL DETERMINATION OF RADIAL MOMENTS OF AN AEROSOL SIZE DISTRIBUTION FROM MEASUREMENTS OF LIGHT TRANSMITTANCE AND SCATTERING Ernie R. Lewis and Stephen E. Schwartz Brookhaven National Laboratory, Upton, NY 11933 ses@bnl.gov elewis@bnl.gov MOMENTS FROM MEASUREMENTS As each of the measured quantities is linear in the size distribution dn/dr, it is possible to construct linear combinations of measurements that yield

300

Aerosol fabrication methods for monodisperse nanoparticles  

DOE Patents [OSTI]

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.

Jiang, Xingmao; Brinker, C Jeffrey

2014-10-21T23:59:59.000Z

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


301

Electrically Driven Technologies for Radioactive Aerosol Abatement  

SciTech Connect (OSTI)

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.

David W. DePaoli; Ofodike A. Ezekoye; Costas Tsouris; Valmor F. de Almeida

2003-01-28T23:59:59.000Z

302

Development of plutonium aerosol fractionation system  

E-Print Network [OSTI]

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...

Mekala, Malla R.

1993-01-01T23:59:59.000Z

303

Emission Controls Versus Meteorological Conditions in Determining Aerosol Concentrations in Beijing during the 2008 Olympic Games  

SciTech Connect (OSTI)

A series of emission control measures were undertaken in Beijing and the adjacent provinces in China during the 2008 Beijing Olympic Games on August 8th-24th, 2008. This provides a unique opportunity for investigating the effectiveness of emission controls on air pollution in Beijing. We conducted a series of numerical experiments over East Asia for the period of July to September 2008 using a coupled meteorology-chemistry model (WRF-Chem). Model can generally reproduce the observed variation of aerosol concentrations. Consistent with observations, modeled concentrations of aerosol species (sulfate, nitrate, ammonium, black carbon, organic carbon, total particulate matter) in Beijing were decreased by 30-50% during the Olympic period compared to the other periods in July and August in 2008 and the same period in 2007. Model results indicate that emission controls were effective in reducing the aerosol concentrations by comparing simulations with and without emission controls. However, our analysis suggests that meteorological conditions (e.g., wind direction and precipitation) are at least as important as emission controls in producing the low aerosol concentrations appearing during the Olympic period. Transport from the regions surrounding Beijing determines the temporal variation of aerosol concentrations in Beijing. Based on the budget analysis, we suggest that emission control strategy should focus on the regional scale instead of the local scale to improve the air quality over Beijing.

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

2011-12-12T23:59:59.000Z

304

7, 1463914674, 2007 Aerosol effects on  

E-Print Network [OSTI]

in many ways. They act as cloud condensation and ice nuclei and may have an influence on the hydro.5 W m -2 when micro- physics are included both in stratiform and convective clouds. 1 Introduction15

Boyer, Edmond

305

Atmospheric Aerosol Chemistry Analyzer: Demonstration of feasibility  

SciTech Connect (OSTI)

This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The project objective was to demonstrate the technical feasibility of an Atmospheric Aerosol Chemistry Analyzer (AACA) that will provide a continuous, real-time analysis of the elemental (major, minor and trace) composition of atmospheric aerosols. The AACA concept is based on sampling the atmospheric aerosol through a wet cyclone scrubber that produces an aqueous suspension of the particles. This suspension can then be analyzed for elemental composition by ICP/MS or collected for subsequent analysis by other methods. The key technical challenge was to develop a wet cyclone aerosol sampler suitable for respirable particles found in ambient aerosols. We adapted an ultrasonic nebulizer to a conventional, commercially available, cyclone aerosol sampler and completed collection efficiency tests for the unit, which was shown to efficiently collect particles as small as 0.2 microns. We have completed the necessary basic research and have demonstrated the feasibility of the AACA concept.

Mroz, E.J.; Olivares, J.; Kok, G.

1996-04-01T23:59:59.000Z

306

Assessment of the mixing state and cloud nucleating efficiency of Asian aerosols using aircraft-based measurements of hygroscopicity  

E-Print Network [OSTI]

to identify internally/externally mixed aerosols would result in a more accurate distinction between the two and strengthen the correlations made here. - 21 REFERENCES Ackerman, A. S., O. B. Toon, J. P. Taylor, D. W. Johnson, P. V. Hobbs..., and R. J. Ferek, 2000: Effects of aerosols on cloud albedo: Evaluation of Twomey?s parameterization of cloud susceptibility using measurements of ship tracks. J. Atmos. Science, 57, 2684-2695. Brechtel, F. J., and S. M. Kreidenweis...

Thomas, Timothy William

2006-08-16T23:59:59.000Z

307

An Aerosol Condensation Model for Sulfur Trioxide  

SciTech Connect (OSTI)

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

Grant, K E

2008-02-07T23:59:59.000Z

308

Impact of Aerosols on Tropical Cyclones: An Investigation Using Convection-permitting Model Simulation  

SciTech Connect (OSTI)

The role of aerosols effect on two tropical cyclones over Bay of Bengal are investigated using a convection permitting model with two-moment mixed-phase bulk cloud microphysics scheme. The simulation results show the role of aerosol on the microphysical and dynamical properties of cloud and bring out the change in efficiency of the clouds in producing precipitation. The tracks of the TCs are hardly affected by the changing aerosol types, but the intensity exhibits significant sensitivity due to the change in aerosol contribution. It is also clearly seen from the analyses that higher heating in the middle troposphere within the cyclone center is in response to latent heat release as a consequence of greater graupel formation. Greater heating in the middle level is particularly noticeable for the clean aerosol regime which causes enhanced divergence in the upper level which, in turn, forces the lower level convergence. As a result, the cleaner aerosol perturbation is more unstable within the cyclone core and produces a more intense cyclone as compared to other two perturbations of aerosol. All these studies show the robustness of the concept of TC weakening by storm ingestion of high concentrations of CCN. The consistency of these model results gives us confidence in stating there is a high probability that ingestion of high CCN concentrations in a TC will lead to weakening of the storm but has little impact on storm direction. Moreover, as pollution is increasing over the Indian sub-continent, this study suggests pollution may be weakening TCs over the Bay of Bengal.

Hazra, Anupam; Mukhopadhyay, P.; Taraphdar, Sourav; Chen, J. P.; Cotton, William R.

2013-07-16T23:59:59.000Z

309

E-Print Network 3.0 - aerosol microphysical characteristics Sample...  

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

new particle formation, aerosol microphysical evolution, three-dimensional transport, and wet... of aerosol microphysical properties. Some of ... Source: Brookhaven...

310

Assessment and analysis of indirect lightning performance of overhead lines  

Science Journals Connector (OSTI)

Abstract This paper presents an efficient method for the assessment of the indirect lightning performance of overhead power lines and analyses the influence of some relevant parameters on the flashover rate. The method is based on a formula to calculate the peak value of lightning-induced voltages in overhead lines over a lossy ground, which considers the front-time of the channel-base current. The results of the method are validated by comparison with results available in the literature. The method is then used to investigate the effect of subsequent strokes on the line flashover rate, leading to the conclusion that their contribution is negligible, as long as no correlation is assumed between front-time and peak value of the strokes (first and subsequent). In the following, the method is used to analyze the influence of some parameters on the lightning performance of overhead lines. The results show that the stroke current front-time influence decreases as the soil resistivity increases, and that a higher front-time leads to a lower flashover rate. It is shown that the use of a fixed front-time T=5.63?s for the first strokes leads to results that match well the results obtained from Cigrs front-time probabilistic distribution. Regarding the return stroke velocity, the results show that, for soils with resistivity higher than 100?m, the flashover rate increases as the return stroke velocity increases. The results also show that a relative velocity vr=0.4 leads to flashover rates that match well the results obtained considering some correlations between return stroke velocity and peak current proposed in the literature. The influence of the correlation between current peak value and front-time for first strokes is also analyzed and it is shown that the correlation reduces the flashover rate. It is also shown that considering this correlation for first strokes and not for subsequent strokes increases the contribution of the latter to the flashover rate, especially for good conducting soils.

J.O.S. Paulino; C.F. Barbosa; I.J.S. Lopes; W.C. Boaventura

2015-01-01T23:59:59.000Z

311

Slurry Phase Iron Catalysts for Indirect Coal Liquefaction  

SciTech Connect (OSTI)

This report describes research conducted to support the DOE program in indirect coal liquefaction. Specifically, we have studied the attrition behavior of Iron Fischer-Tropsch catalysts, their interaction with the silica binder and the evolution of iron phases in a synthesis gas conversion process. The results provide significant insight into factors that should be considered in the design of catalysts for the conversion of coal-derived synthesis gas into liquid fuels.

Abhaya K. Datye

1998-09-10T23:59:59.000Z

312

SLURRY PHASE IRON CATALYSTS FOR INDIRECT COAL LIQUEFACTION  

SciTech Connect (OSTI)

This report describes research conducted to support the DOE program in indirect coal liquefaction. Specifically, they have studied the attrition behavior of iron Fischer-Tropsch catalysts, their interaction with the silica binder and the evolution of iron phases in a synthesis gas conversion process. The results provide significant insight into factors that should be considered in the design of catalysts for converting coal based syngas into liquid fuels.

Abhaya K. Datye

1998-11-19T23:59:59.000Z

313

Indirect constraints on New Physics from the B-factories  

E-Print Network [OSTI]

The existence of New Physics particles can be probed by performing precision measurements of physics phenomena at the few GeV energy scale. The decays of B and D mesons are an excellent example of relatively low energy phenomena that can be sensitive to New Physics scales at the TeV region or above. In this contribution, some recent results obtained by the BABAR and Belle Collaborations are presented, and their implications for the indirect searches for New Physics are discussed.

Gaz, A

2014-01-01T23:59:59.000Z

314

Reactor Materials Program process water piping indirect failure frequency  

SciTech Connect (OSTI)

Following completion of the probabilistic analyses, the LOCA Definition Project has been subject to various external reviews, and as a result the need for several revisions has arisen. This report updates and summarizes the indirect failure frequency analysis for the process water piping. In this report, a conservatism of the earlier analysis is removed, supporting lower failure frequency estimates. The analysis results are also reinterpreted in light of subsequent review comments.

Daugherty, W.L.

1989-10-30T23:59:59.000Z

315

Spatially indirect excitons as primary photoexcitations in conjugated polymers  

Science Journals Connector (OSTI)

We observe competition between picosecond photoinduced absorption and stimulated emission in poly(paraphenylenevinylene) which demonstrates that they derive from two different pathways. We conclude that the photoinduced absorption originates from nonemissive spatially indirect singlet excitons which are formed with quantum yield as high as 0.9. Previous arguments about maximum possible electroluminescence device efficiencies and about lasers in conjugated polymer films are reexamined in light of the prevalence of this species.

M. Yan; L. J. Rothberg; F. Papadimitrakopoulos; M. E. Galvin; T. M. Miller

1994-02-14T23:59:59.000Z

316

Indirect-fired gas turbine bottomed with fuel cell  

DOE Patents [OSTI]

An indirect-heated gas turbine cycle is bottomed with a fuel cell cycle with the heated air discharged from the gas turbine being directly utilized at the cathode of the fuel cell for the electricity-producing electrochemical reaction occurring within the fuel cell. The hot cathode recycle gases provide a substantial portion of the heat required for the indirect heating of the compressed air used in the gas turbine cycle. A separate combustor provides the balance of the heat needed for the indirect heating of the compressed air used in the gas turbine cycle. Hot gases from the fuel cell are used in the combustor to reduce both the fuel requirements of the combustor and the NOx emissions therefrom. Residual heat remaining in the air-heating gases after completing the heating thereof is used in a steam turbine cycle or in an absorption refrigeration cycle. Some of the hot gases from the cathode can be diverted from the air-heating function and used in the absorption refrigeration cycle or in the steam cycle for steam generating purposes.

Micheli, Paul L. (Morgantown, WV); Williams, Mark C. (Morgantown, WV); Parsons, Edward L. (Morgantown, WV)

1995-01-01T23:59:59.000Z

317

Measuring Aerosols Generated Inside Armoured Vehicles Perforated by Depleted Uranium Ammunition  

SciTech Connect (OSTI)

In response to questions raised after the Gulf War about the health significance of exposure to depleted uranium (DU), the U.S. Department of Defense initiated a study designed to provide an improved scientific basis for assessment of possible health effects of soldiers in vehicles struck by these munitions. As part of this study, a series of DU penetrators were fired at an Abrams tank and a Bradley fighting vehicle, and the aerosols generated by vehicle perforation were collected and characterized. A robust sampling system was designed to collect aerosols in this difficult environment and to monitor continuously the sampler flow rates. Interior 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. These data will provide input for future prospective and retrospective dose and health risk assessments of inhaled or ingested DU aerosols. This paper briefly discusses the target vehicles, firing trajectories, aerosol samplers and instrumentation control systems, and the types of analyses conducted on the samples.

Parkhurst, MaryAnn (BATTELLE (PACIFIC NW LAB))

2003-01-01T23:59:59.000Z

318

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

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

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

319

DUAL ORIGIN OF AEROSOLS IN TITAN'S DETACHED HAZE LAYER  

SciTech Connect (OSTI)

We have analyzed scattered light profiles from the Cassini Imaging Science Subsystem, taken at the limb and at several large phase angles. We also used results from an occultation observed by Ultraviolet Imaging Spectrograph in the ultraviolet. We found that particles responsible for the scattering in the detached haze have an effective radius around 0.15 {mu}m and the aerosol size distribution follows a power law (exponent about -4.5). We discuss these results along with microphysical constraints and thermal equilibrium of the detached haze, and we conclude that only a strong interaction with atmospheric dynamics can explain such a structure.

Cours, T.; Burgalat, J.; Rannou, P. [Groupe de Spectrometrie Moleculaire et Atmospherique (GSMA), CNRS UMR-6089, Universite de Reims Champagne-Ardenne, 51687 Reims Cedex 2 (France); Rodriguez, S.; Brahic, A. [Laboratoire AIM, Universite Paris 7, CNRS UMR-7158, CEA-Saclay/DSM/IRFU/SAp, 91191 Gif/Yvette (France); West, R. A., E-mail: thibaud.cours@univ-reims.fr [Jet Propulsion Laboratory M/S 169-237, Pasadena, CA 91109 (United States)

2011-11-10T23:59:59.000Z

320

DOE research on atmospheric aerosols  

SciTech Connect (OSTI)

Atmospheric aerosols are the subject of a significant component of research within DOE`s environmental research activities, mainly under two programs within the Department`s Environmental Sciences Division, the Atmospheric Radiation Measurement (ARM) Program and the Atmospheric Chemistry Program (ACP). Research activities conducted under these programs include laboratory experiments, field measurements, and theoretical and modeling studies. The objectives and scope of these programs are briefly summarized. The ARM Program is the Department`s major research activity focusing on atmospheric processes pertinent to understanding global climate and developing the capability of predicting global climate change in response to energy related activities. The ARM approach consists mainly of testing and improving models using long-term measurements of atmospheric radiation and controlling variables at highly instrumented sites in north central Oklahoma, in the Tropical Western Pacific, and on the North Slope of Alaska. Atmospheric chemistry research within DOE addresses primarily the issue of atmospheric response to emissions from energy-generation sources. As such this program deals with the broad topic known commonly as the atmospheric source-receptor sequence. This sequence consists of all aspects of energy-related pollutants from the time they are emitted from their sources to the time they are redeposited at the Earth`s surface.

Schwartz, S.E.

1995-11-01T23:59:59.000Z

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


321

ARM Aerosol Working Group Meeting  

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

and MFRSR Measurements ARM STM 2008 Norfolk, VA Connor Flynn 1 , Annette Koontz 1 , Anne Jefferson 2 , Jim Barnard 1 , Sally McFarlane 1 1 Pacific Northwest National Laboratory 2 CIRES, University of Colorado, Boulder Progress towards ARM DOE 2008 Performance Metric 3 & 4 * Produce and make available new continuous time series of aerosol total column depth, based on results from the AMF deployment in Niger, Africa. * Produce and make available new continuous time series of retrieved dust properties, based on results from the AMF deployment in Niger, Africa. 0 100 200 300 400 0 20 40 60 80 100 ITF movement and surface RH % RH day of year (2006) 0 100 200 300 400 0 50 100 150 200 250 300 350 day of year wind direction (N = 0, E = 90) 2 4 6 8 10 12 14 Wind speed m/s 0 100 200 300 1.4 1.6 1.8 2 MFRSR Vo for filter2, Niamey

322

Atmospheric Aerosol Optical Properties in the Persian Gulf  

Science Journals Connector (OSTI)

Aerosol optical depth measurements over Bahrain acquired through the ground-based Aerosol Robotic Network (AERONET) are analyzed. Optical depths obtained from ground-based sun/sky radiometers showed a pronounced temporal trend, with a maximum ...

Alexander Smirnov; Brent N. Holben; Oleg Dubovik; Norm T. O'Neill; Thomas F. Eck; Douglas L. Westphal; Andreas K. Goroch; Christophe Pietras; Ilya Slutsker

2002-02-01T23:59:59.000Z

323

Tracing Aerosol Impacts on South Asian Monsoons | U.S. DOE Office of  

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

Science Highlights » 2013 Science Highlights » 2013 » Tracing Aerosol Impacts on South Asian Monsoons Biological and Environmental Research (BER) BER Home About Research Facilities Science Highlights Searchable Archive of BER Highlights External link Benefits of BER Funding Opportunities Biological & Environmental Research Advisory Committee (BERAC) News & Resources Contact Information Biological and Environmental Research U.S. Department of Energy SC-23/Germantown Building 1000 Independence Ave., SW Washington, DC 20585 P: (301) 903-3251 F: (301) 903-5051 E: sc.ber@science.doe.gov More Information » September 2013 Tracing Aerosol Impacts on South Asian Monsoons The effect of pollution aerosols on monsoons. Print Text Size: A A A Subscribe FeedbackShare Page Click to enlarge photo. Enlarge Photo

324

Capstone Depleted Uranium Aerosol Biokinetics, Concentrations, and Doses  

SciTech Connect (OSTI)

One of the principal goals of the Capstone Depleted Uranium (DU) Aerosol Study was to quantify and characterize DU aerosols generated inside armored vehicles by perforation with a DU penetrator. This study consequently produced a database in which the DU aerosol source terms were specified both physically and chemically for a variety of penetrator-impact geometries and conditions. These source terms were used to calculate radiation doses and uranium concentrations for various scenarios as part of the Capstone DU Human Health Risk Assessment (HHRA). This paper describes the scenario-related biokinetics of uranium, and summarizes intakes, chemical concentrations to the organs, and E(50) and HT(50) for organs and tissues based on exposure scenarios for personnel in vehicles at the time of perforation as well as for first responders. For a given exposure scenario (duration time and breathing rates), the range of DU intakes among the target vehicles and shots was not large, about a factor of 10, with the lowest being from a ventilated operational Abrams tank and the highest being for an unventilated Abrams with DU penetrator perforating DU armor. The ranges of committed effective doses were more scenario-dependent than were intakes. For example, the largest range, a factor of 20, was shown for scenario A, a 1-min exposure, whereas, the range was only a factor of two for the first-responder scenario (E). In general, the committed effective doses were found to be in the tens of mSv. The risks ascribed to these doses are discussed separately.

Guilmette, Raymond A.; Miller, Guthrie; Parkhurst, MaryAnn

2009-02-26T23:59:59.000Z

325

Laboratory investigation of chemical and physical properties of soot-containing aerosols  

E-Print Network [OSTI]

SO4-coated soot aerosols; (3) effect of H2SO4 coating on scattering and extinction properties of soot particles. A low-pressure laminar-flow reactor, coupled to ion driftchemical ionization mass spectrometry (ID-CIMS) detection, is used to study...

Zhang, Dan

2006-08-16T23:59:59.000Z

326

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

Science Journals Connector (OSTI)

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

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

2006-08-01T23:59:59.000Z

327

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

SciTech Connect (OSTI)

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.

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

328

Nonequilibrium atmospheric secondary organic aerosol formation and growth  

Science Journals Connector (OSTI)

...Mexico City area are shown...inorganic atmospheric aerosols...2005 ) A large organic aerosol source...photochemical and thermal studies of...Characteristic Group FrequenciesTables and...particle thermal speed...phase-equilibrium in the atmospheric system: Aerosol...Support, Non-U.S...Determination by plasma-based...implications for atmospheric chemistry...2002) A thermal disso-ciation...

Vronique Perraud; Emily A. Bruns; Michael J. Ezell; Stanley N. Johnson; Yong Yu; M. Lizabeth Alexander; Alla Zelenyuk; Dan Imre; Wayne L. Chang; Donald Dabdub; James F. Pankow; Barbara J. Finlayson-Pitts

2012-01-01T23:59:59.000Z

329

Organic and Inorganic Aerosol Below-Cloud Scavenging by  

E-Print Network [OSTI]

concentrations, with an average gravimetric PM1.0 of 8.2 ( 1.6 µg m-3 and an average Fourier transform infrared-rinsing behavior was unaffected by source type. The aerosol OM was hydrophilic throughout the sampling period the description of aerosol lifetimes in global models. Introduction Wet and dry deposition of aerosol particles

Russell, Lynn

330

Project of Aerosol Optical Depth Change in South America  

E-Print Network [OSTI]

AerosolDepth Brazil Bolivia French Guiana Suriname Guyana Venezuela Colombia Ecuador Peru Chile Argentina Suriname Guyana Venezuela Colombia Ecuador Peru Chile Argentina Paraguay Uruguay #12;Statistics of Aerosol M ean D ec 01 to 06 Mean Month AerosolDepth Brazil Bolivia French Guiana Suriname Guyana Venezuela

Frank, Thomas D.

331

DO AEROSOLS CHANGE CLOUD COVER AND AFFECT CLIMATE?  

E-Print Network [OSTI]

AS SEEN FROM SPACE Fire plumes from southern Mexico transported north into Gulf of Mexico. #12;CLOUD IPCC AR4 (2007) 3210-1-2 Forcing, W m-2 CO2 CH4 CFCs N2O Long Lived Greenhouse Gases Tropospheric;AEROSOL INFLUENCES ON CLIMATE AND CLIMATE CHANGE #12;DMS #12;AEROSOL IN MEXICO CITY BASIN #12;AEROSOL

Schwartz, Stephen E.

332

Acidic deposition: State of science and technology. Report 24. Visibility: Existing and historical conditions - causes and effects. Final report  

SciTech Connect (OSTI)

One of the important effects associated with acid precipitation related pollutants is interference with radiation transfer (light transmission) in the atmosphere. An obvious result of such interference is visibility degradation--the impairment of atmospheric clarity or of the ability to perceive form, texture, and color. Climate modification constitutes another, somewhat less obvious, result. The purpose of the NAPAP State of Science/Technology report is to summarize current knowledge regarding these radiation transfer effects. Although the report focuses mainly on visibility issues, it does encompass the emerging field of climate modification. The links between the acid rain problem and radiation transfer effects, although indirect, are quite strong. The principal link is through sulfur dioxide emissions and sulfate aerosols. A secondary link occurs through nitrogen oxide emissions.

Trijonis, J.C.; Malm, W.C.; Pitchford, M.; White, W.H.; Charlson, R.

1990-10-01T23:59:59.000Z

333

A high carrier injection terahertz quantum cascade laser based on indirectly pumped scheme  

SciTech Connect (OSTI)

A Terahertz quantum cascade laser with a rather high injection coupling strength based on an indirectly pumped scheme is designed and experimentally implemented. To effectively suppress leakage current, the chosen quantum cascade module of the device is based on a five-well GaAs/Al{sub 0.25}Ga{sub 0.75}As structure. The device lases up to 151?K with a lasing frequency of 2.67 THz. This study shows that the effect of higher energy states in carrier transport and the long-range tunnel coupling between states that belong to non-neighbouring modules have to be considered in quantum design of structures with a narrow injector barrier. Moreover, the effect of interface roughness scattering between the lasing states on threshold current is crucial.

Razavipour, S. G., E-mail: sgrazavi@uwaterloo.ca; Xu, C.; Wasilewski, Z. R.; Ban, D. [Department of Electrical and Computer Engineering, Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Ave. W., Waterloo, Ontario N2L3G1 (Canada); Dupont, E.; Laframboise, S. R. [National Research Council, Blg. M-50, 1200 Montreal Rd., Ottawa, Ontario K1A0R6 (Canada); Chan, C. W. I.; Hu, Q. [Department of Electrical Engineering and Computer Science, Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

2014-01-27T23:59:59.000Z

334

Direct/indirect detection signatures of nonthermally produced dark matter  

E-Print Network [OSTI]

We study direct and indirect detection possibilities of neutralino dark matter produced non-thermally by e.g. the decay of long-lived particles, as is easily implemented in the case of anomaly or mirage mediation models. In this scenario, large self-annihilation cross sections are required to account for the present dark matter abundance, and it leads to significant enhancement of the gamma-ray signature from the Galactic Center and the positron flux from the dark matter annihilation. It is found that GLAST and PAMELA will find the signal or give tight constraints on such nonthermal production scenarios of neutralino dark matter.

Minoru Nagai; Kazunori Nakayama

2008-07-10T23:59:59.000Z

335

Direct/indirect detection signatures of nonthermally produced dark matter  

SciTech Connect (OSTI)

We study direct and indirect detection possibilities of neutralino dark matter produced nonthermally by, e.g., the decay of long-lived particles, as is easily implemented in the case of anomaly or mirage-mediation models. In this scenario, large self-annihilation cross sections are required to account for the present dark matter abundance, and it leads to significant enhancement of the gamma-ray signature from the galactic center and the positron flux from the dark matter annihilation. It is found that GLAST and PAMELA will find the signal or give tight constraints on such nonthermal production scenarios of neutralino dark matter.

Nagai, Minoru [Theory Group, KEK, Oho 1-1, Tsukuba, Ibaraki 305-0801 (Japan); Nakayama, Kazunori [Institute for Cosmic Ray Research, University of Tokyo, Kashiwa, Chiba 277-8582 (Japan)

2008-09-15T23:59:59.000Z

336

Complementarity between collider, direct detection, and indirect detection experiments  

E-Print Network [OSTI]

We examine the capabilities of planned direct detection, indirect detection, and collider experiments in exploring the 19-parameter p(henomenological)MSSM, focusing on the complementarity between the different search techniques. In particular, we consider dark matter searches at the 7, 8 (and eventually 14) TeV LHC, \\Fermi, CTA, IceCube/DeepCore, and LZ. We see that the search sensitivities depend strongly on the WIMP mass and annihilation mechanism, with the result that different search techniques explore orthogonal territory. We also show that advances in each technique are necessary to fully explore the space of Supersymmetric WIMPs.

Matthew Cahill-Rowley

2014-11-12T23:59:59.000Z

337

Indirect Gas Species Monitoring Using Tunable Diode Lasers  

DOE Patents [OSTI]

A method for indirect gas species monitoring based on measurements of selected gas species is disclosed. In situ absorption measurements of combustion species are used for process control and optimization. The gas species accessible by near or mid-IR techniques are limited to species that absorb in this spectral region. The absorption strength is selected to be strong enough for the required sensitivity and is selected to be isolated from neighboring absorption transitions. By coupling the gas measurement with a software sensor gas, species not accessible from the near or mid-IR absorption measurement can be predicted.

Von Drasek, William A. (Oak Forest, IL); Saucedo, Victor M. (Willowbrook, IL)

2005-02-22T23:59:59.000Z

338

Aerodynamic Focusing Of High-Density Aerosols  

SciTech Connect (OSTI)

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.

Ruiz, D. E.; Fisch, Nathaniel

2014-02-24T23:59:59.000Z

339

Assessment of Aerosol Radiative Impact over Oceanic Regions Adjacent to Indian Subcontinent using Multi-Satellite Analysis  

SciTech Connect (OSTI)

Using data from Ozone Monitoring Instrument (OMI) and Moderate Resolution Imaging Spectroradiometer (MODIS) instruments, we have retrieved regional distribution of aerosol column single scattering albedo (parameter indicative of the relative dominance of aerosol absorption and scattering effects), a most important, but least understood aerosol property in assessing its climate impact. Consequently we provide improved assessment of short wave aerosol radiative forcing (ARF) (on both regional and seasonal scales) estimates over this region. Large gradients in north-south ARF were observed as a consequence of gradients in single scattering albedo as well as aerosol optical depth. The highest ARF (-37 W m-2 at the surface) was observed over the northern Arabian Sea during June to August period (JJA). In general, ARF was higher over northern Bay of Bengal (NBoB) during winter and pre-monsoon period, whereas the ARF was higher over northern Arabian Sea (NAS) during the monsoon and post- monsoon period. The largest forcing observed over NAS during JJA is the consequence of large amounts of desert dust transported from the west Asian dust sources. High as well as seasonally invariant aerosol single scattering albedos (~0.98) were observed over the southern Indian Ocean region far from continents. The ARF estimates based on direct measurements made at a remote island location, Minicoy (8.3N, 73E) in the southern Arabian Sea are in good agreement with the estimates made following multisatellite analysis.

Satheesh, S. K.; Vinoj, V.; Krishnamoorthy, K.

2010-10-01T23:59:59.000Z

340

Aerosol Science and Technology, 41:202216, 2007 Copyright c American Association for Aerosol Research  

E-Print Network [OSTI]

processes, such as con- densation, coagulation, gas-to-particle conversion (Reid et al. 1998), and particle Aerosol size distribution is, along with particle refractive in- dex and shape, one of important

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


341

The near future availability of photovoltaic energy in Europe and Africa in climate-aerosol modeling experiments  

Science Journals Connector (OSTI)

Abstract The near future change in productivity of photovoltaic energy (PVE) in Europe and Africa is assessed by using the climate variables simulated by the ECHAM5-HAM aerosol-climate model, and a model for the performance of photovoltaic systems. The climate simulations are forced by green-house gases emissions from the IPCC SRES B2 scenario. In addition, different scenarios for future anthropogenic aerosols emissions are applied. Thus, the sensitivity of the future PVE productivity to changes in aerosol atmospheric burdens between 2000 and 2030 is analyzed. The analysis indicates that reductions in aerosols emissions in the near future result in an increase of global warming, and a significant response in surface solar radiation and associated PVE productivity. A statistically significant reduction in PVE productivity up to 7% is observed in eastern Europe and northern Africa, while a significant increase up to 10% is observed in western Europe and eastern Mediterranean. The changes in surface solar radiation and PVE productivity are related to global effects of aerosols reduction on the large scale circulation and associated cloud cover pattern, rather than to local effects on the atmospheric optical properties. PVE assessment is then discussed in the frame of the present situation and next decades evolution of the photovoltaic market, highlighting that the effects on productivity induced by industrial and public policies, and technological development are comparable to climate related effects. The presented results encourage the improvement and further use of climate models in assessment of future renewable energies availability.

Marco Gaetani; Thomas Huld; Elisabetta Vignati; Fabio Monforti-Ferrario; Alessandro Dosio; Frank Raes

2014-01-01T23:59:59.000Z

342

A balloon-borne aerosol spectrometer for high altitude low aerosol concentration measurements  

SciTech Connect (OSTI)

Funded by Air Force Wright Aeronautical Laboratory, a new balloon-borne high altitude aerosol spectrometer, for the measurement of cirrus cloud ice crystals, has been developed and successfully flown by Sandia National Laboratories and Radiance Research. This report (1) details the aerosol spectrometer design and construction, (2) discusses data transmission and decoding, (3) presents data collected on three Florida flights in tables and plots. 2 refs., 11 figs., 3 tabs.

Brown, G.S. (Sandia National Labs., Albuquerque, NM (USA)); Weiss, R.E. (Radiance Research, Seattle, WA (USA))

1990-08-01T23:59:59.000Z

343

Response of California temperature to regional anthropogenic aerosol  

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

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

344

Small-Scale Spray Releases: Initial Aerosol Test Results  

SciTech Connect (OSTI)

One of the events postulated in the hazard analysis at the Waste Treatment and Immobilization Plant (WTP) and other U.S. Department of Energy (DOE) nuclear facilities is a breach in process piping that produces aerosols with droplet sizes in the respirable range. The current approach for predicting the size and concentration of aerosols produced in a spray leak involves extrapolating from correlations reported in the literature. These correlations are based on results obtained from small engineered spray nozzles using pure liquids with Newtonian fluid behavior. The narrow ranges of physical properties on which the correlations are based do not cover the wide range of slurries and viscous materials that will be processed in the WTP and across processing facilities in the DOE complex. Two key technical areas were identified where testing results were needed to improve the technical basis by reducing the uncertainty due to extrapolating existing literature results. The first technical need was to quantify the role of slurry particles in small breaches where the slurry particles may plug and result in substantially reduced, or even negligible, respirable fraction formed by high-pressure sprays. The second technical need was to determine the aerosol droplet size distribution and volume from prototypic breaches and fluids, specifically including sprays from larger breaches with slurries where data from the literature are scarce. To address these technical areas, small- and large-scale test stands were constructed and operated with simulants to determine aerosol release fractions and generation rates from a range of breach sizes and geometries. The properties of the simulants represented the range of properties expected in the WTP process streams and included water, sodium salt solutions, slurries containing boehmite or gibbsite, and a hazardous chemical simulant. The effect of anti-foam agents was assessed with most of the simulants. Orifices included round holes and rectangular slots. The round holes ranged in size from 0.2 to 4.46 mm. The slots ranged from (width length) 0.3 5 to 2.74 76.2 mm. Most slots were oriented longitudinally along the pipe, but some were oriented circumferentially. In addition, a limited number of multi-hole test pieces were tested in an attempt to assess the impact of a more complex breach. Much of the testing was conducted at pressures of 200 and 380 psi, but some tests were conducted at 100 psi. Testing the largest postulated breaches was deemed impractical because of the large size of some of the WTP equipment. This report presents the experimental results and analyses for the aerosol measurements obtained in the small-scale test stand. It includes a description of the simulants used and their properties, equipment and operations, data analysis methodologies, and test results. The results of tests investigating the role of slurry particles in plugging small breaches are reported in Mahoney et al. (2012). The results of the aerosol measurements in the large-scale test stand are reported in Schonewill et al. (2012) along with an analysis of the combined results from both test scales.

Mahoney, Lenna A.; Gauglitz, Phillip A.; Kimura, Marcia L.; Brown, Garrett N.; Kurath, Dean E.; Buchmiller, William C.; Smith, Dennese M.; Blanchard, Jeremy; Song, Chen; Daniel, Richard C.; Wells, Beric E.; Tran, Diana N.; Burns, Carolyn A.

2012-11-01T23:59:59.000Z

345

Small-Scale Spray Releases: Initial Aerosol Test Results  

SciTech Connect (OSTI)

One of the events postulated in the hazard analysis at the Waste Treatment and Immobilization Plant (WTP) and other U.S. Department of Energy (DOE) nuclear facilities is a breach in process piping that produces aerosols with droplet sizes in the respirable range. The current approach for predicting the size and concentration of aerosols produced in a spray leak involves extrapolating from correlations reported in the literature. These correlations are based on results obtained from small engineered spray nozzles using pure liquids with Newtonian fluid behavior. The narrow ranges of physical properties on which the correlations are based do not cover the wide range of slurries and viscous materials that will be processed in the WTP and across processing facilities in the DOE complex. Two key technical areas were identified where testing results were needed to improve the technical basis by reducing the uncertainty due to extrapolating existing literature results. The first technical need was to quantify the role of slurry particles in small breaches where the slurry particles may plug and result in substantially reduced, or even negligible, respirable fraction formed by high-pressure sprays. The second technical need was to determine the aerosol droplet size distribution and volume from prototypic breaches and fluids, specifically including sprays from larger breaches with slurries where data from the literature are scarce. To address these technical areas, small- and large-scale test stands were constructed and operated with simulants to determine aerosol release fractions and net generation rates from a range of breach sizes and geometries. The properties of the simulants represented the range of properties expected in the WTP process streams and included water, sodium salt solutions, slurries containing boehmite or gibbsite, and a hazardous chemical simulant. The effect of antifoam agents was assessed with most of the simulants. Orifices included round holes and rectangular slots. For the combination of both test stands, the round holes ranged in size from 0.2 to 4.46 mm. The slots ranged from (width length) 0.3 5 to 2.74 76.2 mm. Most slots were oriented longitudinally along the pipe, but some were oriented circumferentially. In addition, a limited number of multi-hole test pieces were tested in an attempt to assess the impact of a more complex breach. Much of the testing was conducted at pressures of 200 and 380 psi, but some tests were conducted at 100 psi. Testing the largest postulated breaches was deemed impractical because of the much larger flow rates and equipment that would be required. This report presents the experimental results and analyses for the aerosol measurements obtained in the small-scale test stand. It includes a description of the simulants used and their properties, equipment and operations, data analysis methodologies, and test results. The results of tests investigating the role of slurry particles in plugging small breaches are reported in Mahoney et al. (2012). The results of the aerosol measurements in the large-scale test stand are reported in Schonewill et al. (2012) along with an analysis of the combined results from both test scales.

Mahoney, Lenna A.; Gauglitz, Phillip A.; Kimura, Marcia L.; Brown, Garrett N.; Kurath, Dean E.; Buchmiller, William C.; Smith, Dennese M.; Blanchard, Jeremy; Song, Chen; Daniel, Richard C.; Wells, Beric E.; Tran, Diana N.; Burns, Carolyn A.

2013-05-29T23:59:59.000Z

346

Large-Scale Spray Releases: Initial Aerosol Test Results  

SciTech Connect (OSTI)

One of the events postulated in the hazard analysis at the Waste Treatment and Immobilization Plant (WTP) and other U.S. Department of Energy (DOE) nuclear facilities is a breach in process piping that produces aerosols with droplet sizes in the respirable range. The current approach for predicting the size and concentration of aerosols produced in a spray leak involves extrapolating from correlations reported in the literature. These correlations are based on results obtained from small engineered spray nozzles using pure liquids with Newtonian fluid behavior. The narrow ranges of physical properties on which the correlations are based do not cover the wide range of slurries and viscous materials that will be processed in the WTP and across processing facilities in the DOE complex. Two key technical areas were identified where testing results were needed to improve the technical basis by reducing the uncertainty due to extrapolating existing literature results. The first technical need was to quantify the role of slurry particles in small breaches where the slurry particles may plug and result in substantially reduced, or even negligible, respirable fraction formed by high-pressure sprays. The second technical need was to determine the aerosol droplet size distribution and volume from prototypic breaches and fluids, specifically including sprays from larger breaches with slurries where data from the literature are scarce. To address these technical areas, small- and large-scale test stands were constructed and operated with simulants to determine aerosol release fractions and generation rates from a range of breach sizes and geometries. The properties of the simulants represented the range of properties expected in the WTP process streams and included water, sodium salt solutions, slurries containing boehmite or gibbsite, and a hazardous chemical simulant. The effect of anti-foam agents was assessed with most of the simulants. Orifices included round holes and rectangular slots. The round holes ranged in size from 0.2 to 4.46 mm. The slots ranged from (width length) 0.3 5 to 2.74 76.2 mm. Most slots were oriented longitudinally along the pipe, but some were oriented circumferentially. In addition, a limited number of multi-hole test pieces were tested in an attempt to assess the impact of a more complex breach. Much of the testing was conducted at pressures of 200 and 380 psi, but some tests were conducted at 100 psi. Testing the largest postulated breaches was deemed impractical because of the large size of some of the WTP equipment. The purpose of this report is to present the experimental results and analyses for the aerosol measurements obtained in the large-scale test stand. The report includes a description of the simulants used and their properties, equipment and operations, data analysis methodology, and test results. The results of tests investigating the role of slurry particles in plugging of small breaches are reported in Mahoney et al. 2012a. The results of the aerosol measurements in the small-scale test stand are reported in Mahoney et al. (2012b).

Schonewill, Philip P.; Gauglitz, Phillip A.; Bontha, Jagannadha R.; Daniel, Richard C.; Kurath, Dean E.; Adkins, Harold E.; Billing, Justin M.; Burns, Carolyn A.; Davis, James M.; Enderlin, Carl W.; Fischer, Christopher M.; Jenks, Jeromy WJ; Lukins, Craig D.; MacFarlan, Paul J.; Shutthanandan, Janani I.; Smith, Dennese M.

2012-12-01T23:59:59.000Z

347

The Aerosol Modeling Testbed: A community tool to objectively evaluate aerosol process modules  

SciTech Connect (OSTI)

This study describes a new modeling paradigm that significantly advances how the third activity is conducted while also fully exploiting data and findings from the first two activities. The Aerosol Modeling Testbed (AMT) is a computational framework for the atmospheric sciences community that streamlines the process of testing and evaluating aerosol process modules over a wide range of spatial and temporal scales. The AMT consists of a fully-coupled meteorology-chemistry-aerosol model, and a suite of tools to evaluate the performance of aerosol process modules via comparison with a wide range of field measurements. The philosophy of the AMT is to systematically and objectively evaluate aerosol process modules over local to regional spatial scales that are compatible with most field campaigns measurement strategies. The performance of new treatments can then be quantified and compared to existing treatments before they are incorporated into regional and global climate models. Since the AMT is a community tool, it also provides a means of enhancing collaboration and coordination among aerosol modelers.

Fast, Jerome D.; Gustafson, William I.; Chapman, Elaine G.; Easter, Richard C.; Rishel, Jeremy P.; Zaveri, Rahul A.; Grell, Georg; Barth, Mary

2011-03-02T23:59:59.000Z

348

Modeling aerosol growth by aqueous chemistry in nonprecipitating stratiform cloud  

SciTech Connect (OSTI)

A new microphysics module based on a two-dimensional (2D) joint size distribution function representing both interstitial and cloud particles is developed and applied to studying aerosol processing in non-precipitating stratocumulus clouds. The module is implemented in a three-dimensional dynamical framework of a large-eddy simulation (LES) model and in a trajectory ensemble model (TEM). Both models are used to study the modification of sulfate aerosol by the activation - aqueous chemistry - resuspension cycle in shallow marine stratocumulus clouds. The effect of particle mixing and different size-distribution representations on modeled aerosol processing are studied in a comparison of the LES and TEM simulations with the identical microphysics treatment exposes and a comparison of TEM simulations with a 2D fixed and moving bin microphysics. Particle mixing which is represented in LES and neglected in the TEM leads to the mean relative per particle dry mass change in the TEM simulations being about 30% lower than in analogous subsample of LES domain. Particles in the final LES spectrum are mixed in from different parcels, some of which have experienced longer in-cloud residence times than the TEM parcels, all of which originated in the subcloud layer, have. The mean relative per particle dry mass change differs by 14% between TEM simulations with fixed and moving bin microphysics. Finally, the TEM model with the moving bin microphysics is used to evaluate assumptions about liquid water mass partitioning among activated cloud condensation nuclei (CCN) of different dry sizes. These assumptions are used in large-scale models to map the bulk aqueous chemistry sulfate production, which is largely proportional to the liquid water mass, to the changes in aerosol size distribution. It is shown that the commonly used assumptions that the droplet mass is independent of CCN size or that the droplet mass is proportional to the CCN size to the third power do not perform well in the considered case. The explicitly predicted water partitioning indicates that the mean mass of droplets participating in the models aqueous chemistry calculations is proportional to the dry CCN size.

Ovchinnikov, Mikhail; Easter, Richard C.

2010-07-29T23:59:59.000Z

349

Source Apportionment of Carbonaceous Aerosols using  

E-Print Network [OSTI]

are different than the collection of particles from water Filtration has high efficiency for all sizes Size Condensation Nuclei (CCN) Human health Carbonaceous aerosol implicated as important for toxicity and adverse of particulate matter Again, agreement between these two approaches would give a high level of confidence

Einat, Aharonov

350

Photophoretic levitation of engineered aerosols for geoengineering  

Science Journals Connector (OSTI)

...W. Keith Energy and Environmental...space-based solar scattering...The salient advantage of sulfate aerosols...instrument. Disadvantages of sulfates...concentrating solar power systems...higher energy than molecules...solving the energy balance equation...ratio of solar-spectrum to thermal-spectrum...two of the disadvantages of stratospheric...

David W. Keith

2010-01-01T23:59:59.000Z

351

Modeling Semivolatile Organic Aerosol Mass Emissions from  

E-Print Network [OSTI]

in diluted diesel and wood combustion exhaust are interpreted using a two-component absorptive with dilution of both wood smoke and diesel exhaust can be described by two lumped compounds in roughly equal. Introduction Sources of organic aerosol such as diesel engines and wood stoves emit semivolatile organic

Stanier, Charlie

352

3, 59195976, 2003 The nitrate aerosol  

E-Print Network [OSTI]

ACPD 3, 5919­5976, 2003 The nitrate aerosol field over Europe M. Schaap et al. Title Page Abstract of Utrecht, Institute of Marine and Atmospheric Science, PO Box 80005, 3508 TA, Utrecht, The Netherlands 2, The Netherlands 3 Netherlands Energy Research Foundation (ECN), PO Box 1, 1755 LE Petten, The Netherlands 4 Joint

Paris-Sud XI, Université de

353

Preparation of ferric-sulfide-based catalysts using an aerosol technique  

SciTech Connect (OSTI)

Iron sulfides are used as catalysts for direct coal liquefaction. They are reasonably active, cheap, and environmentally benign. This permits their use as once-through, non-regenerated catalysts. Our work in this area is based on the products of disproportionation of ferric sulfide, produced in sufficiently small particle sizes. The small particle sizes have been produced by in-situ impregnation or by using an aerosol reactor. This talk will concentrate on the aerosol process. The resulting particles have been characterized and used as catalysts for coal liquefaction. The effects of precursor solution concentration and the pressure and temperature in the aerosol reactor on the performance of the catalysts have been noted. We have recently investigated the effect of adding small amounts of a second metal to the catalyst. Multi-metal catalysts prepared to date with the aerosol technique include Fe-Cu-S and Fe-Zn-S, each with 10% additive, and Fe-Cu-Zn-S, with 10% Cu and 5% Zn.

Stiller, A.H.; Dadyburjor, D.B.; Stinespring, C.D. [West Virginia Univ., Morgantown, WV (United States)] [and others

1995-12-01T23:59:59.000Z

354

Applications of Capstone Depleted Uranium Aerosol Risk Data to Military Combat Risk Management  

SciTech Connect (OSTI)

Risks to personnel engaged in military operations include not only the threat of enemy firepower but also risks from exposure to other hazards such as radiation. Combatant commanders of the U. S. Army carefully weigh risks of casualties before implementing battlefield actions using an established paradigm that take these risks into consideration. As a result of the inclusion of depleted uranium (DU) anti-armor ammunition in the conventional (non-nuclear) weapons arsenal, the potential for exposure to DU aerosols and its associated chemical and radiological effects becomes an element of the commanders risk assessment. The Capstone DU Aerosol Study measured the range of likely DU oxide aerosol concentrations created inside a combat vehicle perforated with a DU munition, and the Capstone Human Health Risk Assessment (HHRA) estimated the associated doses and calculated risks. This paper focuses on the development of a scientific approach to adapt the risks from DUs non uniform dose distribution within the body using the current U.S. Department of Defense (DoD) radiation risk management approach. The approach developed equates the Radiation Exposure Status (RES) categories to the estimated radiological risks of DU and makes use of the Capstone-developed Renal Effects Group (REG) as a measure of chemical risk from DU intake. Recommendations are provided for modifying Army guidance and policy in order to better encompass the potential risks from DU aerosol inhalation during military operations.

Daxon, Eric G.; Parkhurst, MaryAnn; Melanson, Mark A.; Roszell, Laurie E.

2009-03-01T23:59:59.000Z

355

Deposition of biological aerosols on HVAC heat exchangers  

SciTech Connect (OSTI)

Many biologically active materials are transported as bioaerosols 1-10 {micro}m in diameter. These particles can deposit on cooling and heating coils and lead to serious indoor air quality problems. This paper investigates several of the mechanisms that lead to aerosol deposition on fin and tube heat exchangers. A model has been developed that incorporates the effects of several deposition mechanisms, including impaction, Brownian and turbulent diffusion, turbophoresis, thermophoresis, diffusiophoresis, and gravitational settling. The model is applied to a typical range of air velocities that are found in commercial and residential HVAC systems 1 - 6 m/s (200 - 1200 ft/min), particle diameters from 1 - 8 {micro}m, and fin spacings from 3.2 - 7.9 fins/cm (8 - 16 fins/inch or FPI). The results from the model are compared to results from an experimental apparatus that directly measures deposition on a 4.7 fins/cm (12 FPI) coil. The model agrees reasonably well with this measured data and suggests that cooling coils are an important sink for biological aerosols and consequently a potential source of indoor air quality problems.

Siegel, Jeffrey; Walker, Ian

2001-09-01T23:59:59.000Z

356

Aerosol analysis for the regional air pollution study. Final report  

SciTech Connect (OSTI)

The design and operation of an aerosol sampling and analysis program implemented during the 1975 to 1977 St. Louis Regional Air Pollution Study is described. A network of ten samplers were operated at selected sites in the St. Louis area and the total mass and elemental composition of the collected particulates were determined. Sampling periods of 2 to 24 hours were employed. The samplers were capable of collecting aerosol particles in two distinct size ranges corresponding to fine (< 2.4 ..mu..m diameter) and coarse (> 2.4 ..mu..m diameter) particles. This unique feature allowed the separation of the particulate samples into two distinct fractions with differing chemical origins and health effects. The analysis methods were also newly developed for use in the St. Louis RAPS study. Total particulate mass was measured by a beta-particle attenuation method in which a precision of +- 5 ..mu..m/cm/sup 2/ could be obtained in a one minute measurement time. Elemental compositions of the samples were determined using an energy dispersive x-ray fluorescence method in which detectable limits of 5 ng/cm/sup 2/ or less were routinely achieved for elements ranging in atomic number from Al to Pb. The advantages of these analytical methods over more conventional techniques arise from the ability to automate the measurements. During the course of the two year study, a total of more than 35,000 individual samples were processed and a total of 28 concentrations measured for each sample.

Jaklevic, J.M.; Gatti, R.C.; Goulding, F.S.; Loo, B.W.; Thompson, A.C.

1980-05-01T23:59:59.000Z

357

UNDERSTANDING THE INFLUENCES OF ATMOSPHERIC AEROSOLS ON CLIMATE AND CLIMATE CHANGE  

E-Print Network [OSTI]

.ecd.bnl.gov/steve BOB BRAWDY / AP #12;OVERVIEW Aerosol influences on climate and climate change Earth's energy balance remarks #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 AS SEEN FROM SPACE Fire plumes from southern

Schwartz, Stephen E.

358

Options for controlling condensation aerosols to meet opacity standards  

SciTech Connect (OSTI)

The article gives results of an analysis of the condensing aerosol problem and an evaluation of possible control approaches to reduce the downwind detached plume opacity. The opacity of such plumes may be reduced by reducing the concentration of condensible vapors, the in-stack concentration of fine particles, or both. Results of the analysis indicate that, for low concentrations of condensible vapors, the detached-plume opacity may be adequately controlled by reducing the in-stack fine-particulate concentration alone. For high concentrations of condensible vapors, however, reduction of in-stack fine particulate concentration alone may not be effective: reduction of vapor concentration may be necessary along with particulate removal for adequate reduction of plume opacity. Different combinations of levels of reduction of vapor concentration and particulate-phase concentration are possible to achieve a desired result; and thus may be optimized to obtain a cost-effective combination.

Damle, A.S.; Ensor, D.S.; Sparks, L.E.

1987-01-01T23:59:59.000Z

359

Linearity of Climate Response to Increases in Black Carbon Aerosols  

SciTech Connect (OSTI)

The impact of absorbing aerosols on global climate are not completely understood. Here, we present results of idealized experiments conducted with the Community Atmosphere Model (CAM4) coupled to a slab ocean model (CAM4-SOM) to simulate the climate response to increases in tropospheric black carbon aerosols (BC) by direct and semi-direct effects. CAM4-SOM was forced with 0, 1x, 2x, 5x and 10x an estimate of the present day concentration of BC while maintaining their estimated present day global spatial and vertical distribution. The top of the atmosphere (TOA) radiative forcing of BC in these experiments is positive (warming) and increases linearly as the BC burden increases. The total semi-direct effect for the 1x experiment is positive but becomes increasingly negative for higher BC concentrations. The global average surface temperature response is found to be a linear function of the TOA radiative forcing. The climate sensitivity to BC from these experiments is estimated to be 0.42 K $\\textnormal W^{-1} m^{2}$ when the semi-direct effects are accounted for and 0.22 K $\\textnormal W^{-1} m^{2}$ with only the direct effects considered. Global average precipitation decreases linearly as BC increases, with a precipitation sensitivity to atmospheric absorption of 0.4 $\\%$ $\\textnormal W^{-1} \\textnormal m^{2}$ . The hemispheric asymmetry of BC also causes an increase in southward cross-equatorial heat transport and a resulting northward shift of the inter-tropical convergence zone in the simulations at a rate of 4$^{\\circ}$N $\\textnormal PW^{-1}$. Global average mid- and high-level clouds decrease, whereas the low-level clouds increase linearly with BC. The increase in marine stratocumulus cloud fraction over the south tropical Atlantic is caused by increased BC-induced diabatic heating of the free troposphere.

Mahajan, Salil [ORNL; Evans, Katherine J [ORNL; Hack, James J [ORNL; Truesdale, John [National Center for Atmospheric Research (NCAR)

2013-01-01T23:59:59.000Z

360

Stable carbon fractionation in size-segregated aerosol particles produced by controlled biomass burning  

Science Journals Connector (OSTI)

Abstract Six different biomass fuel types (wood pellets, sunflower stalk pellets, straw pellets, buckwheat shells, mixed biomass waste pellets, and grain screenings) and wastewater sludge pellets were burned under controlled conditions to determine the effect of the biomass type on the emitted particulate matter mass and stable carbon isotope composition of bulk and size-segregated particles. Aerosol particles were sampled using the total suspended particle (TSP) sampler and a micro-orifice uniform deposit impactor (MOUDI). The results demonstrated that particle emissions were dominated by the submicron particles (size <1m) in all biomass types. However, significant differences in emissions of submicron particles and their dominant sizes were found between different biomass fuels. The isotopic fractionation between aerosol particles and original biomass material varied from ?0.940.23 to 1.120.16. The largest negative fractionation ?0.940.23 was obtained for the wood pellet fuel type while the largest positive isotopic fractionation (1.120.16) was observed during the grain screenings combustion. The carbon isotope composition of MOUDI samples compared very well with the isotope composition of TSP samples indicating consistency of the results. The measurements of the stable carbon isotope ratio in size-segregated aerosol particles suggested that combustion processes could strongly affect isotopic fractionation in aerosol particles of different sizes thereby potentially affecting an interpretation of ambient atmospheric observations.

A. Garbaras; A. Masalaite; I. Garbariene; D. Ceburnis; E. Krugly; V. Remeikis; E. Puida; K. Kvietkus; D. Martuzevicius

2015-01-01T23:59:59.000Z

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


361

E-Print Network 3.0 - adjusted indirect comparison Sample Search...  

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

Technologies and Information Sciences 49 Summary of the August 2009 Forum Center for BioEnergy Sustainability (CBES) Summary: )? And how much would the indirect land-use...

362

Feasibility Analysis of Two Indirect Heat Pump Assisted Solar Domestic Hot Water Systems.  

E-Print Network [OSTI]

??This thesis is an analysis of the simulated performance of two indirect heat pump assisted solar domestic hot water (i-HPASDHW) systems compared to two base (more)

Sterling, Scott Joseph

2011-01-01T23:59:59.000Z

363

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

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

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

364

Tropospheric Aerosol Optical Thickness from the GOCART Model and Comparisons with Satellite and Sun Photometer Measurements  

Science Journals Connector (OSTI)

The Georgia Institute of TechnologyGoddard Global Ozone Chemistry Aerosol Radiation and Transport (GOCART) model is used to simulate the aerosol optical thickness ? for major types of tropospheric aerosols including sulfate, dust, organic carbon ...

Mian Chin; Paul Ginoux; Stefan Kinne; Omar Torres; Brent N. Holben; Bryan N. Duncan; Randall V. Martin; Jennifer A. Logan; Akiko Higurashi; Teruyuki Nakajima

2002-02-01T23:59:59.000Z

365

Retrieval of ozone and nitrogen dioxide concentrations from Stratospheric Aerosol and Gas Experiment III (SAGE III)  

E-Print Network [OSTI]

Retrieval of ozone and nitrogen dioxide concentrations from Stratospheric Aerosol and Gas extinction. We retrieve ozone and nitrogen dioxide number densities and aerosol extinction from transmission), Retrieval of ozone and nitrogen dioxide concentrations from Stratospheric Aerosol and Gas Experiment III

366

Statistical analysis of aerosol species, trace gasses, and meteorology in Chicago  

E-Print Network [OSTI]

possible pollutant sources. Keywords Atmospheric aerosols . Canonical correlation analysis . Chicago air pollution studies involve collection and anal- ysis of atmospheric aerosols and concurrent meteorol- ogy) and principal component analysis (PCA) were applied to atmospheric aerosol and trace gas concentrations

O'Brien, Timothy E.

367

Dispersion of Cloud Droplet Size Distributions, Cloud Parameterization...  

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

Dispersion of Cloud Droplet Size Distributions, Cloud Parameterizations, and Indirect Aerosol Effects P. H. Daum and Y. Liu Brookhaven National Laboratory Upton, New York...

368

ARM - Events Article  

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

session: * Evidence for the Aerosol Indirect Effect in Shallow Cumuli - J12.2, Larry K. Berg, C. Berkowitz, G. Senum, and S. Springston * Significant Impact of Aerosols on...

369

Aerosol and graphitic carbon content of snow  

SciTech Connect (OSTI)

Snow samples from southern New Mexico, west Texas, Antarctica, and Greenland were analyzed for aerosol and graphitic carbon. Graphitic carbon contents were found to be between 2.2 and 25 ..mu..g L/sup -1/ of snow meltwater; water-insoluble aerosol content varied between 0.62 and 8.5 mg L/sup -1/. For comparison, two samples of Camp Century, Greenland, ice core, having approximate ages of 4,000 and 6,000 years, were also analyzed. Ice core graphitic carbon contents were found to be 2.5 and 1.1 ..mu..g L/sup -1/. copyrightAmerican Geophysical Union 1987

Chy-acute-accentlek, P.; Srivastava, V.; Cahenzli, L.; Pinnick, R.G.; Dod, R.L.; Novakov, T.; Cook, T.L.; Hinds, B.D.

1987-08-20T23:59:59.000Z

370

Exergy analysis of biomass-to-synthetic natural gas (SNG) process via indirect gasification of various biomass feedstock  

Science Journals Connector (OSTI)

This paper presents an exergy analysis of SNG production via indirect gasification of various biomass feedstock, including virgin (woody) biomass as well as waste biomass (municipal solid waste and sludge). In indirect gasification heat needed for endothermic gasification reactions is produced by burning char in a separate combustion section of the gasifier and subsequently the heat is transferred to the gasification section. The advantages of indirect gasification are no syngas dilution with nitrogen and no external heat source required. The production process involves several process units, including biomass gasification, syngas cooler, cleaning and compression, methanation reactors and SNG conditioning. The process is simulated with a computer model using the flow-sheeting program Aspen Plus. The exergy analysis is performed for various operating conditions such as gasifier pressure, methanation pressure and temperature. The largest internal exergy losses occur in the gasifier followed by methanation and SNG conditioning. It is shown that exergetic efficiency of biomass-to-SNG process for woody biomass is higher than that for waste biomass. The exergetic efficiency for all biomass feedstock increases with gasification pressure, whereas the effects of methanation pressure and temperature are opposite for treated wood and waste biomass.

Caecilia R. Vitasari; Martin Jurascik; Krzysztof J. Ptasinski

2011-01-01T23:59:59.000Z

371

On The Importance of Organic Oxygen for Understanding Organic Aerosol  

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

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

372

Aerosol generation and entrainment model for cough simulations.  

E-Print Network [OSTI]

??The airborne transmission of diseases is of great concern to the public health community. The possible spread of infectious disease by aerosols is of particular (more)

Ersahin, Cem.

2007-01-01T23:59:59.000Z

373

ARM AOS Processing Status and Aerosol Intensive Properties VAP  

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

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

374

Method of Preparing Super-Concentrated Jets From Dense Aerosol...  

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

Michael J. Hay, Ernest J. Valeo, and Nathaniel J. Fisch This is improvement in aerodynamic focusing of dilute aerosol suspensions. All previous work on this subject has...

375

ARM - Field Campaign - Pajarito Aerosol Coupling to Ecosystems...  

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

properties during the winter-spring transition. Opportunity to investigate fire and automobile emission interactions with biogenic aerosols will also harnessed MAOS will be...

376

aerosol influenza transmission: Topics by E-print Network  

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

and Information Sciences Websites Summary: . In preliminary work, we used artificial neural networks (ANNs) to construct global aerosol predictors by learningIntegration...

377

E-Print Network 3.0 - aerosol particle size Sample Search Results  

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

Summary: of aerosol over many orders-of-magnitude of particle size range, from subcritical clusters on the molecular... to modeling aerosol dynamics under conditions of new...

378

E-Print Network 3.0 - aerosol modeling decadal Sample Search...  

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

Geosciences 8 Absorbing aerosols and pre-summer monsoon hydroclimate variability over the Indian subcontinent: The challenge in investigating links Summary: in the aerosol-monsoon...

379

E-Print Network 3.0 - aerosol radiative forcing Sample Search...  

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

No. DE- Summary: : WHY MEASUREMENTS ALONE CANNOT QUANTIFY AEROSOL RADIATIVE FORCING OF CLIMATE CHANGE Stephen E. Schwartz... of radiative forcing of climate change by aerosols,...

380

E-Print Network 3.0 - aerosols nanometriques application Sample...  

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

is studying how aerosol particles affect everything from Summary: of aerosol particles on climate change, public health, and renewable energy applications. In particular, he......

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


381

E-Print Network 3.0 - aerosol lung inhalation Sample Search Results  

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

aerosolized by means... is aerosolized upon inhalation by utilizing the ... Source: Groningen, Rijksuniversiteit - Centre for Ecological and Evolutionary Studies, Department of...

382

E-Print Network 3.0 - aerosol condensation model Sample Search...  

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

Applied Science Collection: Environmental Sciences and Ecology 8 DETERMINING AEROSOL RADIATIVE FORCING AT ARM SITES Summary: OF AEROSOL DIRECT FORCING By linear model and by...

383

E-Print Network 3.0 - aerosol code comparisons Sample Search...  

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

and Ecology 4 Estimates of global radiative forcing derived from the GlobAEROSOL dataset Summary: -sky direct aerosol radiative forcing. The Edwards and Slingo (1996)...

384

Aerosol-Cloud-Precipitation Interactions in the Trade Wind Boundary Layer.  

E-Print Network [OSTI]

??This dissertation includes an overview of aerosol, cloud, and precipitation properties associated with shallow marine cumulus clouds observed during the Barbados Aerosol Cloud Experiment (BACEX, (more)

Jung, Eunsil

2012-01-01T23:59:59.000Z

385

E-Print Network 3.0 - aerosols harbor diverse Sample Search Results  

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

Cloud & Aerosol Process Group CSDESRLNOAA Presented at: NIST... Aerosol Metrology for Climate Workshop 15th March, 2011 12;Deposition Snow Darkens and Warms BC...

386

E-Print Network 3.0 - aerosol light absorption Sample Search...  

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

AND Summary: population centers were used to calculate the aerosol forcing due to light scattering and absorption. Directly... , NY www.bnl.gov ABSTRACT Aerosols influence...

387

Large Aerosols Play Unexpected Role in Ganges Valley | U.S. DOE...  

Office of Science (SC) Website

The data have revealed that large aerosols in this region absorb a greater amount of light than expected. The Science Aerosol particles in the atmosphere may absorb solar...

388

E-Print Network 3.0 - aerosol atmospheric interactions Sample...  

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

for Climate Summary: order estimates of aerosol-climate interaction But... only Earth System Models can include all... of the interactions (in theory at least) 12;Aerosols <>...

389

E-Print Network 3.0 - alkali sulfate aerosol Sample Search Results  

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

Aerosol Formation during... " and "Mechanism of Alkali Sulfate Aerosols Formation during Biomass Combustion" describe the development... the ... Source: Ris National Laboratory...

390

E-Print Network 3.0 - atmospheric aerosol size Sample Search...  

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

for about ten percent of all aerosols in the atmosphere. We... , can actually absorb solar energy and warm the atmosphere. Atmospheric aerosols are very important... by...

391

ASPEN modeling of the Tri-State indirect liquefaction process  

SciTech Connect (OSTI)

The ASPEN process simulator has been used to model an indirect liquefaction flowsheet patterned after that of the Tri-State project. This flowsheet uses Lurgi moving-bed gasification with synthesis gas conversion to methanol followed by further processing to gasoline using the Mobil MTG process. Models developed in this study include the following: Lurgi gasifier, Texaco gasifier, synthesis gas cooling, Rectisol, methanol synthesis, methanol-to-gasoline, CO-shift, methanation, and naphtha hydrotreating. These models have been successfully developed in modular form so that they can be used to simulate a number of different flowsheets or process alternatives. Simulations of the Tri-State flowsheet have been made using two different coal feed rates and two types of feed coal. The overall simulation model was adjusted to match the Tri-State flowsheet values for methanol, LPG, isobutane, and gasoline. As a result of this adjustment, the MTG reactor yield structure necessary to match the flowsheet product rates was determined. The models were exercised at different flow rates and were unaffected by such changes, demonstrating their range of operability. The use of Illinois No. 6 coal, with its lower ash content, resulted in slightly higher production rates for each of the products as compared to use of the Kentucky coal.

Begovich, J.M.; Clinton, J.H.; Johnson, P.J.; Barker, R.E.

1983-01-01T23:59:59.000Z

392

Direct and indirect detection of dissipative dark matter  

E-Print Network [OSTI]

We study the constraints from direct detection and solar capture on dark matter scenarios with a subdominant dissipative component. This dissipative dark matter component in general has both a symmetric and asymmetric relic abundance. Dissipative dynamics allow this subdominant dark matter component to cool, resulting in its partial or total collapse into a smaller volume inside the halo (e.g., a dark disk) as well as a reduced thermal velocity dispersion compared to that of normal cold dark matter. We first show that these features considerably relax the limits from direct detection experiments on the couplings between standard model (SM) particles and dissipative dark matter. On the other hand, indirect detection of the annihilation of the symmetric dissipative dark matter component inside the Sun sets stringent and robust constraints on the properties of the dissipative dark matter. In particular, IceCube observations force dissipative dark matter particles with mass above 50 GeV to either have a small coupling to the SM or a low local density in the solar system, or to have a nearly asymmetric relic abundance. Possible helioseismology signals associated with purely asymmetric dissipative dark matter are discussed, with no present constraints.

JiJi Fan; Andrey Katz; Jessie Shelton

2013-12-04T23:59:59.000Z

393

Improved Fischer-Tropsch catalysts for indirect coal liquefaction  

SciTech Connect (OSTI)

The Fischer-Tropsch synthesis (FTS)reaction is the established technology for the production of liquid fuels from coal by an indirect route using coal-derived syngas (CO + H{sub 2}). Modern FTS catalysts are potassium- and copper-promoted iron preparations. These catalysts exhibit moderate activity with carbon monoxide-rich feedstocks such as the syngas produced by advanced coal gasification processes. However, the relatively large yields of by-product methane and high-molecular-weight hydrocarbon waxes detract from the production of desired liquid products in the C{sub 5}-C{sub 16} range needed for motor and aviation fuel. The goal of this program is to decrease undesirable portions of the FTS hydrocarbon yield by altering the Schultz-Flory polymerization product distribution through design and formulation of improved catalysts. Two approaches were taken: (1) reducing the yield of high-molecular-weight hydrocarbon waxes by using highly dispersed catalysts produced from surface-confined multiatomic clusters on acid supports and (2) suppressing methane production by uniformly pretreating active, selective conventional FTS catalysts with submonolayer levels of sulfur.

Wilson, R.B. Jr.; Tong, G.T.; Chan, Y.W.; Huang, H.W.; McCarty, J.G.

1989-02-01T23:59:59.000Z

394

Development of Aerosol Models for Radiative Flux Calculations at ARM Sites: Utility of Trajectory Clustering for Characterizing Aerosol Climatology  

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

Development of Aerosol Models for Radiative Flux Development of Aerosol Models for Radiative Flux Calculations at ARM Sites: Utility of Trajectory Clustering for Characterizing Aerosol Climatology E. Andrews Cooperative Institute for Research in the Environment University of Colorado Boulder, Colorado E. Andrews, J. A. Ogren, P. J. Sheridan, and J. M. Harris Climate Monitoring and Diagnostics Laboratory National Oceanic and Atmospheric Administration Boulder, Colorado P. K. Quinn Pacific Marine Environmental Laboratory National Oceanic and Atmospheric Administration Seattle, Washington Abstract The uncertainties associated with assumptions of generic aerosol properties in radiative transfer codes are unknown, which means that these uncertainties are frequently invoked when models and

395

INTEGRATED DIRECT/INDIRECT ADAPTIVE ROBUST CONTROL OF MULTI-DOF HYDRAULIC ROBOTIC ARMS  

E-Print Network [OSTI]

INTEGRATED DIRECT/INDIRECT ADAPTIVE ROBUST CONTROL OF MULTI-DOF HYDRAULIC ROBOTIC ARMS Amit/indirect adaptive robust control (DIARC) strategy for a hydraulically actuated 3-DOF robotic arm. To avoid the need FOUNDATION GRANT NO. CMS-0600516. draulic robot arm (a scaled down version of an industrial back- hoe

Yao, Bin

396

Optical absorption from an indirect transition in bismuth nanowires M. R. Black,1,  

E-Print Network [OSTI]

Optical absorption from an indirect transition in bismuth nanowires M. R. Black,1, * P. L; published 30 December 2003 Simulations of the optical absorption in bismuth nanowires resulting from an indirect interband L-T-point transition are presented. The absorption dependence at room temperature

Cronin, Steve

397

Capsule implosion optimization during the indirect-drive National Ignition Campaign  

E-Print Network [OSTI]

and systematic uncertainties in setting the key ignition laser and target parameters due to residual measurement. INTRODUCTION A. Indirect-drive design The National Ignition Facility (NIF)1 is a 192 beam, 1.8 MJ 0.35 lm laserCapsule implosion optimization during the indirect-drive National Ignition Campaign O. L. Landen,1

398

Atmospheric Aerosols Aging Involving Organic Compounds and Impacts on Particle Properties  

E-Print Network [OSTI]

) and chemical reactions (oxidation of particles by gas-phase oxidants and heterogeneous reactions between gas molecules and particles).5 For example, when initially formed, soot particles are hydrophobic and fractal in morphology, with low effective density... particles have a ? value of 1.0; whereas fractal ones will have ? > 1.0. Measurements of Aerosol Optical Properties The optical system consisted of a commercial integrating Nephelometer (Model 3563, TSI) and a CRDS connected in series.20 The particles...

Qiu, Chong

2013-02-01T23:59:59.000Z

399

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

SciTech Connect (OSTI)

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

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

2009-03-01T23:59:59.000Z

400

ASPEN simulation of an indirect coal-liquefaction plant  

SciTech Connect (OSTI)

The methanol synthesis, the Mobil methanol-to-gasoline (MTG) conversion, and the synthetic natural gas (SNG) upgrading steps in an indirect coal-liquefaction plant were simulated and analyzed using the Advanced System for Process Engineering (ASPEN). The plant, proposed to be built for the Tri-State Synfuels Company in Western Kentucky, converts 19,900,000 kg/d (21,900 ST/D) of coal to 3.31 x 10/sup 6/ kg gasoline/day and 2.99 x 10/sup 6/ kg liquefied petroleum gas/day. Closure of the simulation with the design mass balance was within 99.7% through the MTG processing step. Simulated estimates for the mass flow of crude methanol were only 0.2% less than those for the proposed design. A molar recycle-to-feed ratio of 4.5 yielded a crude methanol product stream similar to the design case. The purity of the crude methanol was calulated to be 98%, in comparison with the proposed design purity of 95%. The ASPEN simulation revealed the design case to have overestimated gasoline production by 16,400 kg/h (36,000 lb/h) or 11.8%, and underestimated wastewater production by 15,000 kg/h (33,000 lb/h) or 7.2%. The alkylation section of the MTG step and the methanation section of the SNG upgrading steps were only partially simulated due to limited process information. An overall energy balance indicated a net production of energy (4.9 GW or 17 x 10/sup 9/ Btu/h) from the plant. Most (91%) of the energy comes from methanol synthesis.

Chien, P.S.J.; Luther, M.A.

1982-06-01T23:59:59.000Z

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


401

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

402

Climatology of aerosol optical depth in northcentral Oklahoma: 19922008  

E-Print Network [OSTI]

of aerosol models; for identification of aerosols from spe- cific events (e.g., the Central American fires Radiation Measurement Program central facility near Lamont, Oklahoma, since the fall of 1992. Most dimming; that is, the decrease in solar radiation reaching Earth's surface. Additionally, the wavelength

403

Aerosol penetration through transport lines  

E-Print Network [OSTI]

, which is given below: A = 1+ 1 1 ] + 1. 05 . ')rk (cos r( + 4 /'(" sin'" (r) where Stk is Stokes number (Stk=Cp J3, 'U. /9pd, ), c( is the angle between the axis of the inlet nozzle and the free stream, R is the ratio of free stream velocity... is the Froude number (U?, '/gR), R, represents the coupled effects of drag force (Stk) and lift force (Pl) (2Stk/Pl '), Stk is the Stokes number (rU?, /R, ), Pl is the particle lifl number (rdUm/R, ), r = Cp J3, ' / 1 gpd, , t, = 0. 3246(p Jp)D, /(uk?r)", k...

Dileep, V.R.

2012-06-07T23:59:59.000Z

404

Determination of vertical profiles of aerosol extinction, single scatter  

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

Determination of vertical profiles of aerosol extinction, single scatter Determination of vertical profiles of aerosol extinction, single scatter albedo and asymmetry parameter at Barrow. Sivaraman, Chitra Pacific Northwest National Laboratory Flynn, Connor Pacific Northwest National Laboratory Turner, David University of Wisconsin-Madison Category: Aerosols Efforts are currently underway to run and evaluate the Broadband Heating Rate Profile project at the ARM North Slope of Alaska (NSA) Barrow site for the time period March 2004 - February 2005. The Aerosol Best-Estimate (ABE) Value-Added Procedure (VAP) is to provide continuous estimates of vertical profiles of aerosol extinction, single-scatter albedo, and asymmetry parameter above the Northern Slopes of Alaska (NSA) facility. In the interest of temporal continuity, we have developed an algorithm that

405

ARM - Field Campaign - MArine Stratus Radiation Aerosol and Drizzle  

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

govCampaignsMArine Stratus Radiation Aerosol and Drizzle (MASRAD) IOP govCampaignsMArine Stratus Radiation Aerosol and Drizzle (MASRAD) IOP Campaign Links Science Plan AMF Point Reyes Website AMF Point Reyes Data Plots Related Campaigns MASRAD: Pt. Reyes Stratus Cloud and Drizzle Study 2005.07.07, Coulter, AMF MASRAD: Cloud Condensate Nuclei Chemistry Measurements 2005.07.01, Berkowitz, AMF MASRAD - Aerosol Optical Properties 2005.06.29, Strawa, AMF MASRAD:Sub-Micron Aerosol Measurements 2005.06.20, Wang, AMF MASRAD: Cloud Study from the 2NFOV at Pt. Reyes Field Campaign 2005.06.02, Wiscombe, AMF Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : MArine Stratus Radiation Aerosol and Drizzle (MASRAD) IOP 2005.03.14 - 2005.09.14 Website : http://www.arm.gov/sites/amf/pye/ Lead Scientist : Mark Miller

406

Aerosol Retrievals under Partly Cloudy Conditions: Challenges and Perspectives  

SciTech Connect (OSTI)

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

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

2011-06-01T23:59:59.000Z

407

Do Diurnal Aerosol Changes Affect Daily Average Radiative Forcing?  

SciTech Connect (OSTI)

Strong diurnal variability of aerosol has been observed frequently for many urban/industrial regions. How this variability may alter the direct aerosol radiative forcing (DARF), however, is largely unknown. To quantify changes in the time-averaged DARF, we perform an assessment of 29 days of high temporal resolution ground-based data collected during the Two-Column Aerosol Project (TCAP) on Cape Cod, which is downwind of metropolitan areas. We demonstrate that strong diurnal changes of aerosol loading (about 20% on average) have a negligible impact on the 24-h average DARF, when daily averaged optical properties are used to find this quantity. However, when there is a sparse temporal sampling of aerosol properties, which may preclude the calculation of daily averaged optical properties, large errors (up to 100%) in the computed DARF may occur. We describe a simple way of reducing these errors, which suggests the minimal temporal sampling needed to accurately find the forcing.

Kassianov, Evgueni I.; Barnard, James C.; Pekour, Mikhail S.; Berg, Larry K.; Michalsky, Joseph J.; Lantz, K.; Hodges, G. B.

2013-06-17T23:59:59.000Z

408

Atmospheric aerosol monitoring at the Pierre Auger Observatory  

SciTech Connect (OSTI)

For a ground based cosmic-ray observatory the atmosphere is an integral part of the detector. Air fluorescence detectors (FDs) are particularly sensitive to the presence of aerosols in the atmosphere. These aerosols, consisting mainly of clouds and dust, can strongly affect the propagation of fluorescence and Cherenkov light from cosmic-ray induced extensive air showers. The Pierre Auger Observatory has a comprehensive program to monitor the aerosols within the atmospheric volume of the detector. In this paper the aerosol parameters that affect FD reconstruction will be discussed. The aerosol monitoring systems that have been deployed at the Pierre Auger Observatory will be briefly described along with some measurements from these systems.

Cester, R.; Chiosso, M.; Chirin, J.; Clay, R.; Dawson, B.; Fick, B.; Filipcic, A.; Garcia, B.; Grillo, A.; Horvat, M.; Iarlori, M.; Malek, M.; Matthews, J.; Matthews,; Melo, D.; Meyhandan, R.; Mostafa, M.; Mussa, R.; Prouza, M.; Raefert, B.; Rizi, V.

2005-07-01T23:59:59.000Z

409

Optimization of aerosol penetration through transport lines  

E-Print Network [OSTI]

, F is the numerical reading from the fluorometer , L is the liquid volume of the measured (23) solution, 8 is the testing time for each filter, and V is the filter flow rate during the sample period. Penetration, P, of aerosol through... defined maxima on the penetration versus Reynolds number (or flow rate, since the diameter is constant for a given tube) curves for each tube size. Also, in order to observe an optimum tube diameter , a (10) fixed flow rate of 86 L/min was tested for a...

Wong Luque, Fermin Samuel

2012-06-07T23:59:59.000Z

410

A shrouded probe aerosol sampling cyclone  

E-Print Network [OSTI]

the air stream. In the present design, three concentric shrouds and a probe will be attached to the entrance of the cyclone. The shroud concept was first used in an aircraft-horne sampling device for collecting tropospheric aerosol particles... by A. R. McFarland and S. A. Batterman. College Station, Texas: 1989. 5. Strauss, W. and S. J. Nainwaring: Air Pollution. London, Baltimore, Maryland: Edward Arnold, 1984. pp. 95-96. 6. Moore, N. E. , and A. R. NcFarland: Stairmand-Type Sampling...

Little, Stewart Craig

2012-06-07T23:59:59.000Z

411

Method of dispersing particulate aerosol tracer  

DOE Patents [OSTI]

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.

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

1988-01-01T23:59:59.000Z

412

Sources and Formation of OrganicSources and Formation of Organic Aerosols in our AtmosphereAerosols in our Atmosphere  

E-Print Network [OSTI]

;Carnegie Mellon University Smog Chamber Air supply Computer Temperature control Clean air 10 m3 Teflon spectrometer Aerosol mass spectrometerOzone monitor Air supply Computer Temperature control Clean air 10 m3 on temperature Hevap also needed Assumes no interactions among organic aerosol species or with inorganics. #12

Einat, Aharonov

413

Beryllium Carcinogenesis. I. Inhalation Exposure of Rats to Beryllium Sulfate Aerosol  

Science Journals Connector (OSTI)

...aerosol at a mean atmospheric concentration of...aerosol at a mean atmospheric concentration of...in the drinking water) for 2 weeks...a glass aerosol generator, with an airflow...chamber, distilled water was disseminated...aerosol generation, atmospheric concentration control...

Andrew L. Reeves; Daniel Deitch; and Arthur J. Vorwald

1967-03-01T23:59:59.000Z

414

Improving aerosol distributions below clouds by assimilating satellite-retrieved cloud droplet number  

Science Journals Connector (OSTI)

...remainder of the map to the...distributions for mass, number, composition...such as vertical velocity and aerosol composition...updated aerosol mass for each compound...aerosols in trade wind cumulus observed by...spectrum of updraft velocities and the internally...Starting from aerosol mass (M) and number...

Pablo E. Saide; Gregory R. Carmichael; Scott N. Spak; Patrick Minnis; J. Kirk Ayers

2012-01-01T23:59:59.000Z

415

spectra from size-resolved particle samples col-lected from the Southeastern Aerosol Visibility  

E-Print Network [OSTI]

and acrolein aerosols. We believe that these transformations are due to acid-catalyzed heterogeneous reac

Bishop, James K.B.

416

Three-photon-absorption spectroscopy in an indirect-gap material: CdI2  

Science Journals Connector (OSTI)

The three-photon absorption (3PA) spectrum of an indirect-gap material (CdI2) has been measured at 10 K by monitoring the resulting self-trapped-exciton emission. The contribution of excitonic transitions has been evidenced for excitation energies near the indirect gap, while the contribution of allowed and forbidden indirect transitions has been shown for excitation energies far from the gap. The spectral behavior of the 3PA coefficient has been described by parametric formulas, which are analogous to the ones successfully applied for 3PA in direct-gap materials.

M. Lepore; R. Tommasi; I. M. Catalano

1993-03-15T23:59:59.000Z

417

Hyperspectral Aerosol Optical Depths from TCAP Flights  

SciTech Connect (OSTI)

4STAR (Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research), the worlds 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 4STARs spatially-resolved high-frequency hyperspectral products as a reliable tool for climate studies and satellite validation.

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

418

Sulfate aerosols and polar stratospheric cloud formation  

SciTech Connect (OSTI)

Before the discovery of the Antarctic ozone hole, it was generally assumed that gas-phase chemical reactions controlled the abundance of stratospheric ozone. However, the massive springtime ozone losses over Antarctica first reported by Farman et al in 1985 could not be explained on the basis of gas-phase chemistry alone. In 1986, Solomon et al suggested that chemical reactions occurring on the surfaces of polar stratospheric clouds (PSCs) could be important for the observed ozone losses. Since that time, an explosion of laboratory, field, and theoretical research in heterogeneous atmospheric chemistry has occurred. Recent work has indicated that the most important heterogeneous reaction on PSCs is ClONO[sub 2] + HCl [yields] Cl[sub 2] + HNO[sub 3]. This reaction converts inert chlorine into photochemically active Cl[sub 2]. Photolysis of Cl[sub 2] then leads to chlorine radicals capable of destroying ozone through very efficient catalytic chain reactions. New observations during the second Airborne Arctic Stratospheric Expedition found stoichiometric loss of ClONO[sub 2] and HCl in air processed by PSCs in accordance with reaction 1. Attention is turning toward understanding what kinds of aerosols form in the stratospheric, their formation mechanism, surface area, and specific chemical reactivity. Some of the latest findings, which underline the importance of aerosols, were presented at a recent National Aeronautics and Space Administration workshop in Boulder, Colorado.

Tolbert, M.A. (Univ. of Colorado, Boulder, CO (United States))

1994-04-22T23:59:59.000Z

419

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

SciTech Connect (OSTI)

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

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

2011-02-01T23:59:59.000Z

420

Biomass heat pipe reformerdesign and performance of an indirectly heated steam gasifier  

Science Journals Connector (OSTI)

Indirectly heated dual fluidized bed (DFB) gasifiers are a promising option for the production ... syngas, in particular in the small- and medium-scale range. The application of so-called ... pipes solves the key...

Jrgen Karl

2014-03-01T23:59:59.000Z

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


421

Development of an indirect competitive ELISA for the detection of protective antibodies in pasteurella pneumonia  

E-Print Network [OSTI]

An indirect competitive enzyme-linked immunosorbent assay (ELISA) for the detection of antibodies against Pasteurella haemolytica was developed. The capsular material of the bacteria was extracted in saline for use as antigen. The antigen...

Sewell, Julie Elizabeth

2012-06-07T23:59:59.000Z

422

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

SciTech Connect (OSTI)

For studying the formation and photochemical/thermal reactions of aerosols relevant to the troposphere, a unique, high-volume, slow-flow, stainless steel aerosol flow system equipped with 5 UV lamps has been constructed and characterized experimentally. The total flow system length 6 is 8.5 m and includes a 1.2 m section used for mixing, a 6.1 m reaction section and a 1.2 m 7 transition cone at the end. The 45.7 cm diameter results in a smaller surface to volume ratio than is found in many other flow systems and thus reduces the potential contribution from wall reactions. The latter are also reduced by frequent cleaning of the flow tube walls which is made feasible by the ease of disassembly. The flow tube is equipped with ultraviolet lamps for photolysis. This flow system allows continuous sampling under stable conditions, thus increasing the amount of sample available for analysis and permitting a wide variety of analytical techniques to be applied simultaneously. The residence time is of the order of an hour, and sampling ports located along the length of the flow tube allow for time-resolved measurements of aerosol and gas-phase products. The system was characterized using both an inert gas (CO2) and particles (atomized NaNO3). Instruments interfaced directly to this flow system include a NOx analyzer, an ozone analyzer, relative humidity and temperature probes, a scanning mobility particle sizer spectrometer, an aerodynamic particle sizer spectrometer, a gas chromatograph-mass spectrometer, an integrating nephelometer, and a Fourier transform infrared spectrophotometer equipped with a long path (64 m) cell. Particles collected with impactors and filters at the various sampling ports can be analyzed subsequently by a variety of techniques. Formation of secondary organic aerosol from ?-pinene reactions (NOx photooxidation and ozonolysis) are used to demonstrate the capabilities of this new system.

Ezell, Michael J.; Johnson, Stanley N.; Yu, Yong; Perraud, Veronique; Bruns, Emily; Alexander, M. L.; Zelenyuk, Alla; Dabdub, Donald; Finlayson-Pitts, Barbara J.

2010-05-01T23:59:59.000Z

423

The hybrid plant concept: Combining direct and indirect coal liquefaction processes  

SciTech Connect (OSTI)

The objective of this study is to assess the technical and economic impacts of siting direct two-stage coal liquefaction and indirect liquefaction, using slurry Fischer-Tropsch (F-T) reactors, at the same location. The incentives for this co-siting include the sharing of the large number of common unit process operations and the potential blending of the very different, but complementary, products from the two processes, thereby reducing the refining required to produce specification transportation fuels. Both direct and indirect coal liquefaction share a large number of unit operations. This paper reports on the results of a study that attempts to quantify the extent of these potential synergisms by estimating the costs of transportation fuels produced by direct liquefaction, indirect liquefaction, and by combined direct and indirect hybrid plant configuration under comparable conditions. The technical approach used was to combine the MITRE computer simulated coal liquefaction models for the direct and indirect systems into one integrated model. An analysis of refining and blending of the raw product streams to produce specification diesel and gasoline fuels was included in the direct, indirect and hybrid models so that comparable product slates could be developed. 8 refs., 8 figs., 2 tabs.

Gray, D.; Tomlinson, G.C.; El Sawy, A. (Mitre Corp., McLean, VA (USA))

1990-01-01T23:59:59.000Z

424

Case Study of Water-Soluble Metal Containing Organic Constituents of Biomass Burning Aerosol  

SciTech Connect (OSTI)

Natural and prescribed biomass fires are a major source of atmospheric aerosols that can persist in the atmosphere for long periods of time. Biomass burning aerosols (BBA) can be associated with long range transport of water soluble N?, S?, P?, and metal?containing species. In this study, BBA samples were collected using a particle?into?liquid sampler (PILS) from laboratory burns of vegetation collected on military bases in the southeastern and southwestern United States. The samples were then analyzed using high resolution electrospray ionization mass spectrometry (ESI/HR?MS) that enabled accurate mass measurements for hundreds of species with m/z values between 70 and 1000 and assignment of probable elemental formulae. Mg, Al, Ca, Cr, Mn, Fe, Ni, Cu, Zn, and Ba?containing organometallic species were identified. The results suggest that the biomass may have accumulated metal?containing species that were reemitted during biomass burning. Further research into the sources, persistence, and dispersion of metal?containing aerosols as well as their environmental effects is needed.

Chang-Graham, Alexandra L.; Profeta, Luisa Tm; Johnson, Timothy J.; Yokelson, Robert J.; Laskin, Alexander; Laskin, Julia

2011-01-10T23:59:59.000Z

425

Optimized beryllium target design for indirectly driven inertial confinement fusion experiments on the National Ignition Facility  

SciTech Connect (OSTI)

For indirect drive inertial confinement fusion, Beryllium (Be) ablators offer a number of important advantages as compared with other ablator materials, e.g., plastic and high density carbon. In particular, the low opacity and relatively high density of Be lead to higher rocket efficiencies giving a higher fuel implosion velocity for a given X-ray drive; and to higher ablation velocities providing more ablative stabilization and reducing the effect of hydrodynamic instabilities on the implosion performance. Be ablator advantages provide a larger target design optimization space and can significantly improve the National Ignition Facility (NIF) [J. D. Lindl et al., Phys. Plasmas 11, 339 (2004)] ignition margin. Herein, we summarize the Be advantages, briefly review NIF Be target history, and present a modern, optimized, low adiabat, Revision 6 NIF Be target design. This design takes advantage of knowledge gained from recent NIF experiments, including more realistic levels of laser-plasma energy backscatter, degraded hohlraum-capsule coupling, and the presence of cross-beam energy transfer.

Simakov, Andrei N., E-mail: simakov@lanl.gov; Wilson, Douglas C.; Yi, Sunghwan A.; Kline, John L.; Batha, Steven H. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, New Mexico 87545 (United States)] [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, New Mexico 87545 (United States); Clark, Daniel S.; Milovich, Jose L.; Salmonson, Jay D. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551 (United States)] [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551 (United States)

2014-02-15T23:59:59.000Z

426

Cysteine 295 indirectly affects Ni coordination of carbon monoxide dehydrogenase-II C-cluster  

SciTech Connect (OSTI)

Highlights: CODH-II harbors a unique [Ni-Fe-S] cluster. We substituted the ligand residues of Cys{sup 295} and His{sup 261}. Dramatic decreases in Ni content upon substitutions were observed. All substitutions did not affect Fe-S clusters assembly. CO oxidation activity was decreased by the substitutions. -- Abstract: A unique [NiFeS] cluster (C-cluster) constitutes the active center of Ni-containing carbon monoxide dehydrogenases (CODHs). His{sup 261}, which coordinates one of the Fe atoms with Cys{sup 295}, is suggested to be the only residue required for Ni coordination in the C-cluster. To evaluate the role of Cys{sup 295}, we constructed CODH-II variants. Ala substitution for the Cys{sup 295} substitution resulted in the decrease of Ni content and didnt result in major change of Fe content. In addition, the substitution had no effect on the ability to assemble a full complement of [FeS] clusters. This strongly suggests Cys{sup 295} indirectly and His{sup 261} together affect Ni-coordination in the C-cluster.

Inoue, Takahiro; Takao, Kyosuke; Yoshida, Takashi [Division of Applied Biosciences, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502 (Japan)] [Division of Applied Biosciences, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502 (Japan); Wada, Kei [Organization for Promotion of Tenure Track, University of Miyazaki, Miyazaki 889-1692 (Japan)] [Organization for Promotion of Tenure Track, University of Miyazaki, Miyazaki 889-1692 (Japan); Daifuku, Takashi; Yoneda, Yasuko [Division of Applied Biosciences, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502 (Japan)] [Division of Applied Biosciences, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502 (Japan); Fukuyama, Keiichi [Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043 (Japan)] [Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Sako, Yoshihiko, E-mail: sako@kais.kyoto-u.ac.jp [Division of Applied Biosciences, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502 (Japan)] [Division of Applied Biosciences, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502 (Japan)

2013-11-08T23:59:59.000Z

427

Frontiers in Global Change Seminar Series  

E-Print Network [OSTI]

particles ("aerosols") exert a net cooling effect by directly scattering and absorption of solar radiation (or ice crystal) formation; polluted clouds tend to have more droplets than their pristine that aerosol impacts on clouds (known as "aerosol indirect climatic effects") have a net cooling effect

428

Options for controlling condensation aerosols to meet opacity standards  

SciTech Connect (OSTI)

The opacity of detached plumes formed by condensation of vapors depends upon both the concentration of condensible vapors and the in-stack concentration of fine, submicron, particulate matter. This paper provides an analysis of the condensing aerosol problem and an evaluation of possible control approaches to reduce the downwind detached plume opacity. The opacity of such plumes may be reduced by reducing the concentration of condensible vapors or the in-stack concentration of fine particles or both. The results of the analysis indicate that for low concentrations of condensible vapors the detached plume opacity may be adequately controlled by reducing the in-stack fine particulate concentration alone. For high concentrations of condensible vapors, however, reduction of in-stack fine particulate concentration alone may not be effective, and reduction of vapor concentration may be necessary along with particular removal for adequate reduction of plume opacity. Different combinations of levels of reduction of vapor concentration and particulate phase concentration are possible to achieve a desired result; and thus may be optimized to obtain a cost-effective combination.

Damle, A.S.; Ensor, D.S.; Sparks, L.E.

1987-08-01T23:59:59.000Z

429

Direct Surface Analysis of Time-Resolved Aerosol Impactor Samples with Ultrahigh-Resolution Mass Spectrometry  

E-Print Network [OSTI]

.; Pan, Y.; Mitloehner, F. M. Atmos. Environ. 2012, Submitted. (21) Lundgren, D. A. Journal of the Air Pollution Control Association 1967, 17, 225-9. (22) Schultz, G. A.; Corso, T. N.; Prosser, S. J.; Zhang, S. Anal. Chem. 2000, 72, 4058-4063. 19... in negative health effects caused by air pollution and are linked to increases in respiratory and cardio-vascular diseases2,3. All these particle effects are influenced by the chemical composition of the aerosol particles. A major fraction, often more than 50...

Fuller, Stephen J.; Zhao, Yongjing; Cliff, Steven S.; Wexler, Anthony S.; Kalberer, Markus

2012-10-18T23:59:59.000Z

430

Aerosol mass spectrometry systems and methods  

DOE Patents [OSTI]

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.

Fergenson, David P.; Gard, Eric E.

2013-08-20T23:59:59.000Z

431

Discrimination between thin cirrus and and tropospheric aerosol using  

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

Discrimination between thin cirrus and and tropospheric aerosol using Discrimination between thin cirrus and and tropospheric aerosol using multiple measurements from Darwin ARCS Mitchell, Ross CSIRO Category: Aerosols Thin cirrus cloud occurs frequently in the tropics, and is often difficult to distinguish from tropospheric aerosol on the basis of temporal variations in ground based measurements, since both can be rather spatially uniform. In this study we investigate their discrimination by combining data from three instruments at the Darwin Atmospheric Radiation and Cloud Station (ARCS): the Cimel sun photometer (CSP), the micropulse lidar (MPL), and the total sky imager (TSI). The study was carried out over the dry season of 2005, with the usual widespread burning of tropical savanna leading to extensive smoke plumes. It is shown that the locus of data in

432

Mobile Climate Observatory for Atmospheric Aerosols in India  

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

Atmospheric Aerosols in India Atmospheric Aerosols in India Nainital, India, was the site chosen for deployment of a portable climate research laboratory to study how aerosols impact clouds and energy transfer in the atmosphere. The well-being of hundreds of millions of residents in northeastern India depends on the fertile land around the Ganges River, which is fed by monsoon rains and runoff from the nearby Himalayan Mountains. Any disturbance to the monsoon rains could threaten the population. In the same region, increased industrial activities due to economic growth are releasing small aerosol particles, such as soot and dust, that absorb and scatter sunlight and thus can change cloud formation processes and the heat distribution in the atmosphere. Such changes could greatly increase or

433

PNNL-MILAGRO Aerosol Modeling in Mexico | Open Energy Information  

Open Energy Info (EERE)

PNNL-MILAGRO Aerosol Modeling in Mexico PNNL-MILAGRO Aerosol Modeling in Mexico Jump to: navigation, search Name PNNL-MILAGRO Aerosol Modeling in Mexico Agency/Company /Organization Pacific Northwest National Laboratory Topics Co-benefits assessment Resource Type Dataset, Maps Website http://www.pnl.gov/atmospheric Country Mexico UN Region Latin America and the Caribbean References PNNL-MILAGRO Aerosol Modeling in Mexico[1] "MILGARO surface data includes measurements from Supersites, RAMA (Red Automatica de Monitoreo Atmosferico), Mobile, and Other sites. A description of each site type follows along with a plot of the site locations. Supersites Supersites provide detailed atmospheric chemistry and meteorological measurements; these sites included: T0 (located at the Instituto Mexicano

434

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

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

Discovery Browse Data Related Campaigns Two-Column Aerosol Project (TCAP) 2012.07.01, Berg, AMF Comments? We would love to hear from you Send us a note below or call us at...

435

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

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

Discovery Browse Data Related Campaigns Two-Column Aerosol Project (TCAP) 2012.07.01, Berg, AMF Comments? We would love to hear from you Send us a note below or call us at...

436

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

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

Discovery Browse Data Related Campaigns Two-Column Aerosol Project (TCAP) 2012.07.01, Berg, AMF Comments? We would love to hear from you Send us a note below or call us at...

437

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

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

Discovery Browse Data Related Campaigns Two-Column Aerosol Project (TCAP) 2012.07.01, Berg, AMF Comments? We would love to hear from you Send us a note below or call us at...

438

Application of computational fluid dynamics to aerosol sampling and concentration  

E-Print Network [OSTI]

, FLUENT 6 is used to analyze the performance of aerosol sampling and concentration devices including inlet components (impactors), cyclones, and virtual impactors. The ? ? k model was used to predict particle behavior in Inline Cone Impactor (ICI) and Jet...

Hu, Shishan

2009-05-15T23:59:59.000Z

439

Pressure-flow reducer for aerosol focusing devices  

DOE Patents [OSTI]

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

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

2008-04-22T23:59:59.000Z

440

Persistent sensitivity of Asian aerosol to emissions of nitrogen oxides  

E-Print Network [OSTI]

We use a chemical transport model and its adjoint to examine the sensitivity of secondary inorganic aerosol formation to emissions of precursor trace gases from Asia. Sensitivity simulations indicate that secondary inorganic ...

Kharol, S. K.

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


441

Distinguishing Aerosol Impacts on Climate Over the Past Century  

E-Print Network [OSTI]

Figure 8a). The IE cooling increases snow/ice by about 10% (Their cooling e?ect on surface temperatures promotes ice androw), cooling from the aerosol DE increases snow/ice cover

Koch, Dorothy

2009-01-01T23:59:59.000Z

442

Linearity of Climate Response to Increases in Black Carbon Aerosols  

Science Journals Connector (OSTI)

The impacts of absorbing aerosols on global climate are not completely understood. This paper presents the results of idealized experiments conducted with the Community Atmosphere Model, version 4 (CAM4), coupled to a slab ocean model (CAM4SOM) ...

Salil Mahajan; Katherine J. Evans; James J. Hack; John E. Truesdale

2013-10-01T23:59:59.000Z

443

Impact of aerosols on convective clouds and precipitation  

E-Print Network [OSTI]

: Massachusetts Institute of Technology 77 Massachusetts Avenue, E19-411 Cambridge, MA 02139 (USA) Location to form and a significant attenuator of solar radiation, aerosols affect climate in several ways. Current

444

Continuous air monitor for alpha-emitting aerosol particles  

SciTech Connect (OSTI)

A new alpha Continuous Air Monitor (CAM) sampler is being developed for use in detecting the presence of alpha-emitting aerosol particles. The effort involves design, fabrication and evaluation of systems for the collection of aerosol and for the processing of data to speciate and quantify the alpha emitters of interest. At the present time we have a prototype of the aerosol sampling system and we have performed wind tunnel tests to characterize the performance of the device for different particle sizes, wind speeds, flow rates and internal design parameters. The results presented herein deal with the aerosol sampling aspects of the new CAM sampler. Work on the data processing, display and alarm functions is being done in parallel with the particle sampling work and will be reported separately at a later date. 17 refs., 5 figs., 3 tabs.

McFarland, A.R.; Ortiz, C.A. (Texas A and M Univ., College Station, TX (USA). Dept. of Mechanical Engineering); Rodgers, J.C.; Nelson, D.C. (Los Alamos National Lab., NM (USA))

1990-01-01T23:59:59.000Z

445

Chemical Composition and Cloud Nucleation Ability of Marine Aerosol  

E-Print Network [OSTI]

This study is focused on the chemical composition and cloud nucleation ability of marine aerosol based on two cruise researches over Pacific Ocean and North Atlantic Ocean respectively. Implications of CLAW hypothesis and the factors influencing its...

Deng, Chunhua

2013-12-12T23:59:59.000Z

446

Aerosol-Cloud interactions : a new perspective in precipitation enhancement  

E-Print Network [OSTI]

Increased industrialization and human activity modified the atmospheric aerosol composition and size-distribution during the last several decades. This has affected the structure and evolution of clouds, and precipitation ...

Gunturu, Udaya Bhaskar

2010-01-01T23:59:59.000Z

447

Atmospheric Aerosol Chemistry, Climate Change, and Air Quality  

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

607 Atmospheric Aerosol Chemistry, Climate Change, and Air Quality An EMSL Science Theme Advisory Panel Workshop Workshop Date: January 30, 2013 Prepared for the U.S. Department of...

448

ARM - Field Campaign - Shortwave Radiation and Aerosol Intensive  

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

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

449

A Numerical Sensitivity Study of Aerosol Influence on Immersion Freezing  

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

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

450

Non-intrusive characterization of heat transfer fluid aerosol formation  

E-Print Network [OSTI]

providing an ignition source for the fine aerosol droplets. TI&e Malvern Laser Diffraction Particle Analyzer RING DIODE ARRAY DETECTOR BEAM EXPANDER/ SPATIAL FILTER HE- NE LASER FOURIER TRANSFORM LENS Figure II-Z. Diffraction particle analyzer... providing an ignition source for the fine aerosol droplets. TI&e Malvern Laser Diffraction Particle Analyzer RING DIODE ARRAY DETECTOR BEAM EXPANDER/ SPATIAL FILTER HE- NE LASER FOURIER TRANSFORM LENS Figure II-Z. Diffraction particle analyzer...

Krishna, Kiran

2012-06-07T23:59:59.000Z

451

Measurement of indirect CP asymmetries in $D^0 \\to K^-K^+$ and $D^0 \\to \\pi^-\\pi^+$ decays  

E-Print Network [OSTI]

Time-dependent $CP$ asymmetries in the decay rates of the singly Cabibbo-suppressed decays $D^0\\rightarrow K^-K^+$ and $D^0\\rightarrow \\pi^-\\pi^+$ are measured in $pp$ collision data corresponding to an integrated luminosity of 3.0 fb$^{-1}$ collected by the LHCb experiment. The $D^0$ mesons are produced in semileptonic $b$-hadron decays, where the charge of the accompanying muon is used to determine the initial state as $D^0$ or $\\bar{D}^0$. The asymmetries in effective lifetimes between $D^0$ and $\\bar{D}^0$ decays, which are sensitive to indirect $CP$ violation, are determined to be \\begin{align*} A_{\\Gamma}(K^-K^+) = (-0.134 \\pm 0.077 \\; {}^{+0.026}_{-0.034})\\% \\ , \\\\ A_{\\Gamma}(\\pi^-\\pi^+) = (-0.092\\pm 0.145 \\; {}^{+0.025}_{-0.033})\\% \\ , \\end{align*} where the first uncertainties are statistical and the second systematic. This result is in agreement with previous measurements and with the hypothesis of no indirect $CP$ violation in $D^0$ decays.

Aaij, R; Adinolfi, M; Affolder, A; Ajaltouni, Z; Akar, S; Albrecht, J; Alessio, F; Alexander, M; Ali, S; Alkhazov, G; Cartelle, P Alvarez; Alves, A A; Amato, S; Amerio, S; Amhis, Y; An, L; Anderlini, L; Anderson, J; Andreassen, R; Andreotti, M; Andrews, J E; Appleby, R B; Gutierrez, O Aquines; Archilli, F; Artamonov, A; Artuso, M; Aslanides, E; Auriemma, G; Baalouch, M; Bachmann, S; Back, J J; Badalov, A; Baesso, C; Baldini, W; Barlow, R J; Barschel, C; Barsuk, S; Barter, W; Batozskaya, V; Battista, V; Bay, A; Beaucourt, L; Beddow, J; Bedeschi, F; Bediaga, I; Belogurov, S; Belyaev, I; Ben-Haim, E; Bencivenni, G; Benson, S; Benton, J; Berezhnoy, A; Bernet, R; Bertolin, A; Bettler, M -O; van Beuzekom, M; Bien, A; Bifani, S; Bird, T; Bizzeti, A; Blake, T; Blanc, F; Blouw, J; Blusk, S; Bocci, V; Bondar, A; Bondar, N; Bonivento, W; Borghi, S; Borgia, A; Borsato, M; Bowcock, T J V; Bowen, E; Bozzi, C; Brett, D; Britsch, M; Britton, T; Brodzicka, J; Brook, N H; Bursche, A; Buytaert, J; Cadeddu, S; Calabrese, R; Calvi, M; Gomez, M Calvo; Campana, P; Perez, D Campora; Capriotti, L; Carbone, A; Carboni, G; Cardinale, R; Cardini, A; Carniti, P; Carson, L; Akiba, K Carvalho; Mohr, RCM Casanova; Casse, G; Cassina, L; Garcia, L Castillo; Cattaneo, M; Cauet, Ch; Cavallero, G; Cenci, R; Charles, M; Charpentier, Ph; Chefdeville, M; Chen, S; Cheung, S -F; Chiapolini, N; Chrzaszcz, M; Vidal, X Cid; Ciezarek, G; Clarke, P E L; Clemencic, M; Cliff, H V; Closier, J; Coco, V; Cogan, J; Cogneras, E; Cogoni, V; Cojocariu, L; Collazuol, G; Collins, P; Comerma-Montells, A; Contu, A; Cook, A; Coombes, M; Coquereau, S; Corti, G; Corvo, M; Counts, I; Couturier, B; Cowan, G A; Craik, D C; Crocombe, A C; Torres, M Cruz; Cunliffe, S; Currie, R; D'Ambrosio, C; Dalseno, J; David, P; David, P N Y; Davis, A; De Bruyn, K; De Capua, S; De Cian, M; De Miranda, J M; De Paula, L; De Silva, W; De Simone, P; Dean, C -T; Decamp, D; Deckenhoff, M; Del Buono, L; Dlage, N; Derkach, D; Deschamps, O; Dettori, F; Dey, B; Di Canto, A; Di Domenico, A; Di Ruscio, F; Dijkstra, H; Donleavy, S; Dordei, F; Dorigo, M; Surez, A Dosil; Dossett, D; Dovbnya, A; Dreimanis, KD; Dreimanis, K; Dujany, G; Dupertuis, F; Durante, P; Dzhelyadin, R; Dziurda, A; Dzyuba, A; Easo, S; Egede, U; Egorychev, V; Eidelman, S; Eisenhardt, S; Eitschberger, U; Ekelhof, R; Eklund, L; Rifai, I El; Elsasser, Ch; Ely, S; Esen, S; Evans, H M; Evans, T; Falabella, A; Frber, C; Farinelli, C; Farley, N; Farry, S; Fay, R; Ferguson, D; Albor, V Fernandez; Rodrigues, F Ferreira; Ferro-Luzzi, M; Filippov, S; Fiore, M; Fiorini, M; Firlej, M; Fitzpatrick, C; Fiutowski, T; Fol, P; Fontana, M; Fontanelli, F; Forty, R; Francisco, O; Frank, M; Frei, C; Frosini, M; Fu, J; Furfaro, E; Torreira, A Gallas; Galli, D; Gallorini, S; Gambetta, S; Gandelman, M; Gandini, P; Gao, Y; Pardias, J Garca; Garofoli, J; Tico, J Garra; Garrido, L; Gascon, D; Gaspar, C; Gastaldi, U; Gauld, R; Gavardi, L; Gazzoni, G; Geraci, A; Gersabeck, E; Gersabeck, M; Gershon, T; Ghez, Ph; Gianelle, A; Gian, S; Gibson, V; Giubega, L; Gligorov, V V; Gbel, C; Golubkov, D; Golutvin, A; Gomes, A; Gotti, C; Gndara, M Grabalosa; Diaz, R Graciani; Cardoso, L A Granado; Graugs, E; Graverini, E; Graziani, G; Grecu, A; Greening, E; Gregson, S; Griffith, P; Grillo, L; Grnberg, O; Gui, B; Gushchin, E; Guz, Yu; Gys, T; Hadjivasiliou, C; Haefeli, G; Haen, C; Haines, S C; Hall, S; Hamilton, B; Hampson, T; Han, X; Hansmann-Menzemer, S; Harnew, N; Harnew, S T; Harrison, J; He, J; Head, T; Heijne, V; Hennessy, K; Henrard, P; Henry, L; Morata, J A Hernando; van Herwijnen, E; He, M; Hicheur, A; Hill, D; Hoballah, M; Hombach, C; Hulsbergen, W; Humair, T; Hussain, N; Hutchcroft, D; Hynds, D; Idzik, M; Ilten, P; Jacobsson, R; Jaeger, A; Jalocha, J; Jans, E; Jawahery, A; Jing, F; John, M; Johnson, D; Jones, C R; Joram, C; Jost, B; Jurik, N; Kandybei, S; Kanso, W; Karacson, M; Karbach, T M; Karodia, S; Kelsey, M; Kenyon, I R; Kenzie, M; Ketel, T; Khanji, B; Khurewathanakul, C; Klaver, S; Klimaszewski, K; Kochebina, O; Kolpin, M; Komarov, I; Koopman, R F; Koppenburg, P; Korolev, M; Kravchuk, L; Kreplin, K; Kreps, M; Krocker, G; Krokovny, P; Kruse, F; Kucewicz, W; Kucharczyk, M; Kudryavtsev, V; Kurek, K; Kvaratskheliya, T; La Thi, V N; Lacarrere, D; Lafferty, G; Lai, A; Lambert, D; Lambert, R W; Lanfranchi, G; Langenbruch, C; Langhans, B; Latham, T; Lazzeroni, C; Gac, R Le; van Leerdam, J; Lees, J -P; Lefvre, R; Leflat, A; Lefranois, J; Leroy, O; Lesiak, T; Leverington, B; Li, Y; Likhomanenko, T; Liles, M; Lindner, R; Linn, C; Lionetto, F; Liu, B; Lohn, S; Longstaff, I; Lopes, J H; Lowdon, P; Lucchesi, D; Luo, H; Lupato, A; Luppi, E; Lupton, O; Machefert, F; Machikhiliyan, I V; Maciuc, F; Maev, O; Malde, S; Malinin, A; Manca, G; Mancinelli, G; Manning, P; Mapelli, A; Maratas, J; Marchand, J F; Marconi, U

2015-01-01T23:59:59.000Z

452

Characterisation and dissolution of depleted uranium aerosols produced during impacts of kinetic energy penetrators against a tank  

Science Journals Connector (OSTI)

......Characterisation and dissolution of depleted uranium aerosols produced during impacts...Aerosols produced during impacts of depleted uranium (DU) penetrators against the...Characterisation and dissolution of depleted uranium aerosols produced during impacts......

V. Chazel; P. Gerasimo; V. Debouis; P. Laroche; F. Paquet

2003-07-01T23:59:59.000Z

453

Determination of moisture by an indirect conductivity method  

E-Print Network [OSTI]

Changing Ratio 1 2 3 4 5 $ Water in Ternary ~ure 6 7 Plgo 4 Effect of Changing Alcohol-Acetone Ratio 450 400 Ql 350 300 0 4 5 g later in Soil 6 7 Fig. 5 DetersLination of Moistnre in Air-Dried Soils 19 wetted to the plastic and liquid limits...

Hudgins, Charles Milton

2012-06-07T23:59:59.000Z

454

www.solas-int.org //00//00 surface ocean -lower atmosphere study Mid-Term Strategy theme: Air-sea gas fluxes at Eastern boundary Upwelling and Oxygen Minimum Zone (OMZ) systems  

E-Print Network [OSTI]

to space (aerosol direct effect), and have the potential to modify cloud cover and thus Earth's albedo (aerosol indirect effect). One such molecule is glyoxal that forms secondary organic aerosol (SOA). SOA, the first ship-based detection of glyoxal and iodine oxide was demonstrated over the remote tropical Pacific

455

GaAs/AlGaAs quantum wells with indirect-gap AlGaAs barriers for solar cell applications  

SciTech Connect (OSTI)

We have fabricated GaAs/AlGaAs quantum well (QW) solar cells in which 3?nm-thick QWs and indirect-gap Al{sub 0.78}Ga{sub 0.22}As barriers are embedded, and we studied extraction processes of photogenerated carriers in this QW system. The photocurrent under 700?nm light illumination at voltages close to the open-circuit voltage shows only a small reduction, indicating that the carrier recombination inside QWs is largely suppressed. We attribute this result to an efficient extraction of electrons from the QWs through the X-valley of AlGaAs. The insertion of QWs is shown to be effective in extending the absorption wavelengths and in enhancing the photocurrent. The use of indirect-gap materials as barriers is found to enhance carrier extraction processes, and result in an improved performance of QW solar cells.

Noda, T., E-mail: NODA.Takeshi@nims.go.jp; Otto, L. M.; Elborg, M.; Jo, M.; Mano, T.; Kawazu, T.; Han, L. [National Institute for Materials Science, Tsukuba, Ibaraki 305-0047 (Japan); Sakaki, H. [National Institute for Materials Science, Tsukuba, Ibaraki 305-0047 (Japan); Toyota Technological Institute, Nagoya 468-8511 (Japan)

2014-03-24T23:59:59.000Z

456

Soot microphysical effects on liquid clouds, a multi-model investigation  

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

Soot microphysical effects on liquid clouds, a multi-model investigation Soot microphysical effects on liquid clouds, a multi-model investigation Title Soot microphysical effects on liquid clouds, a multi-model investigation Publication Type Journal Article Year of Publication 2011 Authors Koch, Dorothy M., Yves Balkanski, Susanne E. Bauer, Richard C. Easter, Sylvaine Ferrachat, Steven J. Ghan, Corinna Hoose, Trond Iversen, Alf Kirkevåg, Jon E. Kristjánsson, Xiaohong Liu, Ulrike Lohmann, Surabi Menon, Johannes Quaas, Michael Schulz, Øyvind Seland, Toshihiko Takemura, and N. Yan Journal Atmospheric Chemistry and Physics Volume 11 Pagination 1051-1064 Abstract We use global models to explore the microphysical effects of carbonaceous aerosols on liquid clouds. Although absorption of solar radiation by soot warms the atmosphere, soot may cause climate cooling due to its contribution to cloud condensation nuclei (CCN) and therefore cloud brightness. Six global models conducted three soot experiments; four of the models had detailed aerosol microphysical schemes. The average cloud radiative response to biofuel soot (black and organic carbon), including both indirect and semi-direct effects, is -0.11 Wm-2, comparable in size but opposite in sign to the respective direct effect. In a more idealized fossil fuel black carbon experiment, some models calculated a positive cloud response because soot provides a deposition sink for sulfuric and nitric acids and secondary organics, decreasing nucleation and evolution of viable CCN. Biofuel soot particles were also typically assumed to be larger and more hygroscopic than for fossil fuel soot and therefore caused more negative forcing, as also found in previous studies. Diesel soot (black and organic carbon) experiments had relatively smaller cloud impacts with five of the models <±0.06 Wm-2 from clouds. The results are subject to the caveats that variability among models, and regional and interrannual variability for each model, are large. This comparison together with previously published results stresses the need to further constrain aerosol microphysical schemes. The non-linearities resulting from the competition of opposing effects on the CCN population make it difficult to extrapolate from idealized experiments to likely impacts of realistic potential emission changes.

457

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

E-Print Network [OSTI]

from a low-speed marine diesel engine, Aerosol Sci. Tech. ,from a low-speed marine diesel engine, Aerosol Sci. Tech. ,

Gaston, Cassandra Jayne

2012-01-01T23:59:59.000Z

458

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

E-Print Network [OSTI]

and absorption of solar radiation, and indirectly as cloud condensation nu- clei. The large climate modification

Stoffelen, Ad

459

Section 63  

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

7 7 Indirect Forcing by Anthropogenic Aerosols: A Method for Testing a Parameterization J. E. Penner University of Michigan C. C. Chuang Lawrence Livermore National Laboratory Introduction Atmospheric aerosols affect the radiation balance through direct and indirect effects. The direct effect refers to the scattering and absorption of radiation by the aerosols themselves. The indirect effect refers to changes in cloud optical properties by aerosols that act as cloud condensation nuclei (CCN). An increase in aerosols may result in an increase in cloud drop number concentrations which, in the absence of absorbing aerosols, leads to higher cloud reflectivity. We have developed a parameterization for the indirect effect that is based on a mechanistic description of droplet formation

460

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

SciTech Connect (OSTI)

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

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

2006-10-01T23:59:59.000Z