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Atmospheric Modeling Division Publications: 2002
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This page lists publication titles, citations and abstracts produced by NERL's Atmospheric Modeling Division for the year 2002, organized by Publication Type. Your search has returned
30 Matching Entries.
See also Atmospheric Modeling Division citations with abstracts:
1999,
2000,
2001,
2002,
2003,
2004,
2005,
2006,
2007,
2008
Technical Information Manager: Liz Hope - (919) 541-2785 or hope.elizabeth@epa.gov
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Presented/Published |
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Experiments on Buoyant Plume Dispersion in a Laboratory Convention Tank |
01/01/2002
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Weil, J. C., W. H. Snyder, R. E. Lawson Jr., AND M. S. Shipman. Experiments on Buoyant Plume Dispersion in a Laboratory Convention Tank. BOUNDARY-LAYER METEOROLOGY 102(3):367-414, (2002).
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Buoyant plume dispersion in the convective boundary layer (CBL) is investigated experimentally in a laboratory convection tank. The focus is on highly-buoyant plumes that loft near the CBL capping inversion and resist downward mixing. Highly- buoyant plumes are those with dimensionless buoyancy fluxes F* >/~ 0.1, , where F* = Fb/(Uw2/*zi), Fb is the source buoyancy flux, U is the mean wind speed, w* is the convective velocity scale, and zi is the CBL depth. The aim is to obtain statistically-reliable mean (C) and root-mean-square (rms, sigma c) concentration fields and plume characteristics as a function of F* and the dimensionless distance X = w*x/( U zi), where x is the distance downstream of the source.
The experiments show the following. I) For 3 /- 0.1 , the crosswind-integrated concentration (CWIC) fields exhibit distinctly uniform profiles below zi with a CWIC maximum aloft, in contrast to the nonuniform profiles obtained earlier by Willis and Deardorff (1987). 2) The lateral dispersion (sigma y) variation with X is consistent with Taylor's (1921) theory for F* 1.5 , but sigma c/C exhibits significant increases: a) at the surface and close to the source (X /- 2, with the mixed-layer group collapsing to a single distribution independent of z.
These are the first experiments to obtain all components of the lateral and vertical dispersion parameters (rms meander, relative dispersion, total dispersion) for continuous releases in a convective tank. They also are the first tank experiments to demonstrate agreement with field observations of: 1) the scaled ground-level concentration along the plume centerline, and 2) the lateral dispersion sigma y/zi of buoyant plumes.
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Fluid Modeling of Atmospheric Dispersion in the Convective Boundary Layer |
01/01/2002
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Snyder, W. H., R. E. Lawson Jr., M. S. Shipman, AND J. Lu. Fluid Modeling of Atmospheric Dispersion in the Convective Boundary Layer. BOUNDARY-LAYER METEOROLOGY 102(3):335-336, (2002).
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Study of convective boundary layer (CBL) processes has depended largely upon laboratory analogs for many years. The pioneering work of Willis and Deardorff (1974) and some 35 subsequent papers by the same authors showed that much useful research could be accomplished with a relatively small and economical analog consisting of a tank of water that could be thermally stratified in an upper region, then heated from below to simulate the CBL. Unfortunately, the tank used for much of this early work no longer exists, while the need for additional experimental data continues. The impetus for the development of the current convection tank came from the need to understand the processes involved in the dispersion of pollutants within the CBL, especially the penetration of the inversion above the CBL by continuous plumes and instantaneous puffs of buoyant materials, for use in the development of better regulatory and emergency-preparedness models.
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Atmospheric Mercury Simulation Using the Cmaq Model: Formulation Description and Analysis of Wet Deposition Results |
05/01/2002
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Bullock, O. R. AND K. A. Brehme. Atmospheric Mercury Simulation Using the Cmaq Model: Formulation Description and Analysis of Wet Deposition Results. ATMOSPHERIC ENVIRONMENT 36(13):2135-2146, (2002).
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The Community Multiscale Air Quality (CMAQ) modeling system has recently been adapted to simulate the emission, transport, transformation and deposition of atmospheric mercury in three distinct forms; elemental mercury gas, reactive gaseous mercury, and particulate mercury. Emissions of mercury are currently defined from information developed for and published in EPA's Mercury Study Report to Congress. The atmospheric transport of these three forms of mercury is simulated in the same manner as for all other substances simulated by the CMAQ model to date. Transformations of mercury are simulated with four new chemical reactions within the standard CMAQ gaseous chemistry framework and a highly modified cloud chemistry mechanism which includes a compound-specific speciation for oxidized forms of mercury, seven new aqueous-phase mercury redox reactions, six aqueous mercury chemical equilibria, and a two-way mechanism for the sorption of dissolved oxidized mercury to elemental carbon particles. The CMAQ mercury model simulates the partitioning of reactive gaseous mercury between air and cloud water based on the Henry's constant for mercuric chloride, and a Henry's equilibrium is assumed for elemental mercury also. Particulate mercury is assumed to be incorporated into the aqueous medium during cloud nucleation. Wet and dry deposition is simulated for each of the three forms of mercury. Wet deposition rate is calculated based on precipitation information from the CMAQ meteorological processor and the physicochemical mercury speciation in the cloud chemistry mechanism. Dry deposition rate is calculated based on dry deposition velocity and air concentration information for each of the three forms of mercury. An evaluation of the performance of the CMAQ mercury model compared to weekly observations of mercury wet deposition is performed. The horizontal modeling domain for the evaluation covers the central and eastern United States and adjacent southern Canada. The evaluation results are described for two separate evaluation periods; April 4 to May 2 of 1995, and June 20 to July 18 of 1995.
The information in this document has been funded wholly or in part by the U.S. Environmental Protection Agency (EPA) and has been developed as part of an interagency agreement with the National Oceanic and Atmospheric Administration (NOAA). It has been subject to review by both EPA and NOAA, and has been approved for publication. Mention of trade name or commercial products does not constitute endorsement or recommendation for use.
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A Regional Atmospheric Fate and Transport Model for Atrazine Part II: Evaluation |
11/01/2002
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Cooter, E. J., W. T. Hutzell, W. T. Foreman, AND M. S. Majewski. A Regional Atmospheric Fate and Transport Model for Atrazine Part II: Evaluation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 36(21):4593-4599, (2002).
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The Community Multiscale Air Quality (CMAQ) modeling system has been adapted to simulate the fate and transport of atrazine. The simulation spans April to mid-July 1995 for a domain encompassing the United States and southern Canada east of the Rocky Mountains. Model results for atmospheric concentration and wet deposition are evaluated against field observations taken along the Mississippi River and the shores of Lake Michigan. Model results agree within 10% of published annual atmospheric load estimates for Lake Michigan during 1995, but comparisons with individual 7- and 30-day observed air and rainfall concentrations yield order-of-magnitude differences. In particular, ambient gas-phase concentrations tend to be overpredicted by the model. Uncertainty in short-term predictions of air and rainfall concentrations appear to derive primarily from estimated emissions and precipitation.
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A Regional Atmospheric Fate and Transport Model for Atrazine, Part I: Development and Implementation |
11/01/2002
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Cooter, E. J. AND W. T. Hutzell. A Regional Atmospheric Fate and Transport Model for Atrazine, Part I: Development and Implementation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 36(21):4091-4098, (2002).
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The Community Multiscale Air Quality (CMAQ) modeling system is adapted to simulate the regional transport and fate of atrazine, one of the most widely used herbicides in the United States. Model chemistry and deposition are modified, and a gas-to-particle partitioning algorithm is added to accommodate semivolatile behavior. The partitioning algorithm depends on humidity, temperature, and particulate matter concentration and composition. Results indicate that gaseous atrazine will usually dominate warm season atmospheric concentrations, but particulate form can surpass gas forms when atmospheric humidity is high (>70%) and less-acidic (pH > 2.5) aqueous aerosol component is present. Implementation of the modified CMAQ for atrazine is illustrated, and, within the limits of our current understanding, preliminary transport and fate patterns appear to be reasonable. This research represents one of the first attempts to include a gas-to-particulate matter partitioning mechanism in an Eulerian grid-model.
The information reported here has been funded in part under an Interagency Agreement from the U.S. Environmental Protection Agency, Great Lakes National Program Office (DW13947769-01). It has been subjected to Agency review and approved for publication. Mention of trade names or commercial products does not constitute endorse ment or recommendation for use.
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Multimedia Environmental Distribution of Toxics (Mend-Tox): Part I, Hybrid Compartmental-Spatial Modeling Framework |
04/01/2002
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Cohen, Y. AND E. J. Cooter. Multimedia Environmental Distribution of Toxics (Mend-Tox): Part I, Hybrid Compartmental-Spatial Modeling Framework. Practice Periodical of Hazardous, Toxic and Radioactive Waste Management. American Society of Civil Engineers (ASCE), Reston, VA, 6(2):70-86, (2002).
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An integrated hybrid spatial-compartmental modeling approach is presented for analyzing the dynamic distribution of chemicals in the multimedia environment. Information obtained from such analysis, which includes temporal chemical concentration profiles in various media, mass distribution and intermedia chemical mass fluxes can be used for subsequent exposure and risk analyses. The hybrid modeling framework consists of both uniform (air, water, suspended solids, vegetation, biota, suspended solids, atmospheric aerosols) and non-uniform (soil and sediment) environmental compartments. The interactive system of model equations for the uniform compartments (ODE's) and non-uniform compartments (one-dimensional PDE's) must be solved simultaneously to ensure conservation of mass. In order for the approach to be of practical use parameter input could be minimized through the use of theoretical or empirical description of intermedia transfer processes and estimation methods for associated intermedia transport parameters. Environmental problems are complex and there are numerous possible multimedia analyses scenarios that may be of interest. Therefore, efficient and user-friendly implementations of such models is essential if multimedia analysis is to become a standard environmental tool.
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| JOURNAL |
Monthly and Annual Bias in Weekly (Nadp/Ntn) Versus Daily (Airmon) Precipitation Chemistry Data in the Eastern USA |
11/30/2002
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Gilliland, A. B., G. E. Likens, AND T. J. Butler. Monthly and Annual Bias in Weekly (Nadp/Ntn) Versus Daily (Airmon) Precipitation Chemistry Data in the Eastern USA. ATMOSPHERIC ENVIRONMENT 36(33):5197-5206, (2002).
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Previous comparisons of the data from the National Atmospheric Deposition Program (NADP) National Trends Network (NTN) against collocated event- and daily-sampled data suggest a substantial bias in the concentration of ammonium [NH4+] and concentrations of several base cations, while the comparability of other ion concentrations ranges among the studies. Eight years of collocated data from five NTN and Atmospheric Integrated Research and Monitoring Network (AIRMoN) sites are compared here. Unlike previous analyses, the data from these two datasets were analyzed in the same laboratory using the same analytical methods; therefore, factors that influence concentration differences can be isolated to sampling frequency and sample preservation techniques. For comparison, the relative biases for these data have been calculated using both median value and volume-weighted mean concentrations, following two different approaches in the literature. The results suggest a relative bias of about 10% in [NH4+] (NTN less than AIRMoN), which is smaller than previous estimates that included the influence of inter-laboratory comparisons. The NTN and AIRMoN data are also compared on monthly and annual time scales to consider whether there are strong seasonal or interannual differences between the networks. The annual relative bias of [H+] increases over the analysis period, which also results in a larger total relative bias for [H+] than found in a previous analysis of AIRMoN and NTN data. When comparing NTN and AIRMoN data on a monthly time scales, strong seasonal variations are evident in the relative bias for [H+], [NH4+], and [SO4=]. Large biases in [SO4=] (NTN greater than AIRMoN) on monthly time scales have not been detected in previous analyses where data for all seasons were considered together.
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| JOURNAL |
Multimedia Environmental Distribution of Toxics (Mend-Tox): Part II, Software Implementation and Case Studies |
02/01/2002
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Cohen, Y. AND E. J. Cooter. Multimedia Environmental Distribution of Toxics (Mend-Tox): Part II, Software Implementation and Case Studies. LABORATORY AND ANIMAL INVESTIGATIONS 6(2):87-101, (2002).
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An integrated hybrid spatial-compartmental simulator is presented for analyzing the dynamic distribution of chemicals in the multimedia environment. Information obtained from such analysis, which includes temporal chemical concentration profiles in various media, mass distribution and intermedia chemical mass fluxes can be used for subsequent exposure and risk analyses. The software architecture of the environmental simulator for multimedia environmental distribution of toxics (Mend-Tox) system is presented with emphasis on features that allow for rapid scenario design and analysis of dynamic chemical partitioning in the environment. The model structure is described in a companion paper (Part I). The modular structure of the system provides for flexibility of model design, implementation of a rich selection of simulation scenarios, maintenance and reusability of model components and ease of future improvements. The applicability of Mend-Tox is illustrated for the distribution of PAHs and their nitro-PAH daughter products in the Los Angeles Basin, a retrospective analysis of PCBs in Lake Michigan, and the partitioning behavior of selected volatile organic compounds (VOCs). The level of predictive multimedia analysis represented by these examples yield very reasonable agreement with reported measurements.
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The Scientific Basis of Noaa's Air Quality Forecasting Program |
12/20/2002
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Stockwell, W. R., R. S. Artz, J. Meagher, R. A. Petersen, K. L. Schere, G. A. Grell, S. E. Peckham, A. F. Stein, R. V. Pierce, J. M. O'Sullivan, AND P. Y. Whung. The Scientific Basis of Noaa's Air Quality Forecasting Program. ENVIRONMENTAL MANAGER 8:20-27, (2002).
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For many years, the National Oceanic and Atmospheric Administration (NOAA) has conducted atmospheric research, including chemical and physical measurements, process studies, and the development and evaluation of experimental meteorological and photochemical air quality models. A critical part of NOAA's mission is to provide national environmental forecasts. In response to requests by the U.S. Congress and the National Academy of Sciences, NOAA's mission is being expanded to include forecasts of air quality based on a system of meteorological, photochemical, and emissions models. As a result, NOAA is developing and implementing an air quality modeling system proposed for initial operation in 2004 for forecasting time-resolved ozone and fine particulate matter (PM) nationwide. To do this, NOAA will transition research into an operational system for air quality forecasting.
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| PRESENTATION |
Application of a Microscale Emission Factor Model for Particulate Matter (Microfacpm) in Conjunction With Caline4-Model |
06/23/2002
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Singh, R. B. AND A. H. Huber. Application of a Microscale Emission Factor Model for Particulate Matter (Microfacpm) in Conjunction With Caline4-Model. Presented at Proceedings of the 95th Annual Conference of the AWMA, Baltimore, MD, June 23-27, 2002.
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The United States Environmental Protection Agency's (EPA) National Exposure Research Laboratory is developing improved methods for modeling the pollutant sources through the air pathway to human exposure in significant microenvironments of exposure. As a part of this project, we developed MicroFacPM, a microscale emission factor model for predicting real-world real-time motor vehicle particulate matter (PM10 and PM2.5) emissions. MicroFacPM uses available information on the vehicle fleet composition. The main input variables required are the characterization of on-road vehicle fleet, time and day of the year, ambient temperature, relative humidity and percentage of smoking vehicles. Using the fleet information, MicroFacPM estimates a Composite Emission Factor (milligrams per mile). This paper presents the use of MicroFacPM to calculate the contribution of PM2.5 from motor vehicle sources along an example roadway as input to a roadway air dispersion model. The contribution of PM2.5 is presented per vehicle class (light, heavy duty), vehicle age, fuel type (gasoline, diesel), brake wear and tire wear sources.
The U.S. Environmental Protection Agency through its Office of Reserarch and Development funded the research described here. It has been subjected to Agency review and approved for publication. Mention of trade names or commercial products does not constitute an endorsement or recommendation for use.
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| PRESENTATION |
The Climate-Air Quality Scale Continuum and the Global Emission Inventory Activity |
04/15/2002
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Middleton, P. AND W. G. Benjey. The Climate-Air Quality Scale Continuum and the Global Emission Inventory Activity. Presented at Emission Inventory Conference, Atlanta, GA, April 15-18, 2002.
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The Global Emissions Inventory Activity (GEIA), a core program activity of the International Global Atmospheric Chemistry (IGAC) Project of the International Geosphere-Biosphere Program, develops data and other related information on key chemical emissions to the atmosphere and communicates through its virtual center at www.geiacenter.org. GEIA inventories are developed by international teams and are quality assured through peer review publications. GEIA inventories are traditionally provided on a one degree latitude by one degree longitude grid, as annual and/or seasonal averages, and are aggregated over emission category sectors for individual chemical inventories. As researchers and decision makers world wide become more concerned about the relationship of global climate change and regional air quality, additional flexibility in tools, more highly resolved spatial scales of inventory development, and enhanced coordination among inventory developers will be needed. To address these growing needs, GEIA plans to distribute other important and quality assured emission information through its web site. New information will include underlying data sets from which the emission data were derived (e.g., activity data), global and regional emission inventory data at finer spatial resolutions and/or more refined temporal resolutions and expanded time periods, algorithms for modeling processes selected natural emissions, references to promising new approaches to emission estimates, such as satellite imagery and inverse modeling, and brief summaries of the state of knowledge regarding emissions of individual chemicals and source categories. Through planning and discussions with its network of over 500 emission data developers and collaborators, GEIA will seek to increase the awareness, development, and exchange of versatile data management systems and plans. With sincere and coordinated global community effort that facilitates modifications and quality assurance of databases, inventories that are more useful for examining the relationship between global climate change and regional air quality can be developed.
This paper has been reviewed in accordance with the U.S. Environmental Protection Agency's peer and administrative review policies and approved for presentation and publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.
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| PRESENTATION |
The EPA Multimedia Integrated Modeling System Software Suite |
07/28/2002
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Fine, S., S. Howard, A. Eyth, D. Herington, AND K. Castleton. The EPA Multimedia Integrated Modeling System Software Suite. Presented at Second Federal Interagency Hydrologic Modeling Conference, Las Vegas, NV, July 28-August 1, 2002.
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The U.S. EPA is developing a Multimedia Integrated Modeling System (MIMS) framework that will provide a software infrastructure or environment to support constructing, composing, executing, and evaluating complex modeling studies. The framework will include (1) common software libraries, such as a data input/output library; (2) an infrastructure for constructing, composing, and executing models; and (3) tools to support common modeling and assessment tasks, such as data manipulation, data analysis, visualization, and decision support tools. The framework's goal is to allow modelers to focus more on the scientific and policy issues they are addressing instead of the mechanics of working with models and data, even as the modelers tackle increasingly complex problems. A core component of the MIMS framework is Argonne National Laboratory's Dynamic Information Architecture System (DIAS), which provides a very flexible and powerful approach for bringing together diverse models, including physical, chemical, biological, and socioeconomic. In addition to those capabilities, the MIMS framework provides general user interfaces for working with models, approaches that simplify the incorporation of many models, tools to automate repetitive work, and other capabilities that support modelers. The MIMS framework is intended to support multiple modeling applications, including single and multiple media (e.g., air, water soil) studies. The framework and some of those applications will be demonstrated.
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| PRESENTATION |
Finding a Common Data Representation and Interchange Approach for Multimedia Models |
07/28/2002
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Fine, S. Finding a Common Data Representation and Interchange Approach for Multimedia Models. Presented at Second Federal Interagency Hydrologic Modeling Conference, Las Vegas, NV, July 28-August 1, 2002.
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Within many disciplines, multiple approaches are used to represent and access very similar data (e.g., a time series of values), often due to the lack of commonly accepted standards. When projects must use data from multiple disciplines, the problems quickly compound. Often significant effort is expended reformatting data, tracking down what data represent, and debugging problems caused by mistakes and misunderstandings. To try to address this issue, multiple federal agencies are exploring general approaches that can be used to represent, access, and exchange environmental data. This includes identifying common data structures, software to read and write the data, standards for clearly describing what data represent (metadata), and tools to resolve differences between available data and data needs, all in a manner that supports great flexibility in applications (e.g., change the source of data from a local file to a web site or a database without editing code) and a form that modelers could use. If a more general approach for working with environmental data is found, modelers should be able to easily bring together new combinations of models, data analysis tools, and data sets without changing code or reformatting data. Several existing packages provide at least a partial solution to these requirements, including the Distributed Oceanographic Data System, the Synthetic Environment Data Representation and Interchange Specification, and the Hierarchical Data Format.
The participating Federal agencies will be identifying requirements for a general approach, surveying available off-the-shelf packages, and developing test applications to identify the approaches that come closest to addressing the requirements. If a full solution is not found, then extension of off-the-shelf tools will be developed. This paper reports on this ongoing investigation.
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| PRESENTATION |
Establishment of a Community Modeling and Analysis Support Mechanism |
04/15/2002
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Benjey, W. G. AND R. E. Imhoff. Establishment of a Community Modeling and Analysis Support Mechanism. Presented at Emission Inventory Conference, Atlanta, GA, April 15-18, 2002.
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During the fall of 2001, a Cooperative Research Agreement between the U.S. Environmental Protection Agency and MCNC began a Community Modeling and Analysis System (CMAS) center. The CMAS will foster development, distribution, and use of the Models-3/CMAQ (Community Multiscale Air Quality) air quality modeling system. The CMAS is hosted by MCNC's Environmental Modeling Center in Research Triangle Park, North Carolina. The objectives of the CMAS are to (1) serve as a bridge between members of the Models-3/CMAQ modeling community, (2) encourage the growth of the user community, (3) serve as an information clearinghouse for model applications, emission modeling methods and data, (4) provide education about the models and their uses, (5) maximize the scientific content and performance value of the Models-3/CMAQ system by encouraging the expansion of the contributing developer community and taking advantage of multiple incremental contributions, and (6) provide computer and skill resources to the Models-3/CMAQ modeling community benefitting from economies of scale. Support and development work includes both emission modeling (through the Sparse Matrix Operator Kernel Emission system) and the CMAQ chemistry-transport modeling components. As a community modeling support center, the CMAS is open to all interested participants. The center is organized into five functional parts: (1) Administration, (2) Outreach, (3) Application Support, (4) Software Development, and (5) Modeling Research. The model code accepted and released as a part of Models-3/CMAQ will be open and shared with all. The External Advisory Committee, governing the CMAS policies and priorities, is a technically knowledgeable group including representatives of state and regional agencies, EPA, industry, consultants, academic institutions, and foreign users.
This paper has been reviewed in accordance with the U.S. Environmental Protection Agency's peer and administrative review policies and approved for presentation and publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.
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| PRESENTATION |
Application of a Microscale Emission Factor Model for Particulate Matter (Microfacpm) to Calculate Vehicle Generated Contribution PM 2.5 Emissions |
06/23/2002
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Singh, R. B., A. H. Huber, AND J. N. Braddock. Application of a Microscale Emission Factor Model for Particulate Matter (Microfacpm) to Calculate Vehicle Generated Contribution PM 2.5 Emissions. Presented at 95th Annual Conference of the AWMA, Baltimore, MD, June 23-27, 2002.
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The United States Environmental Protection Agency's (EPA) National Exposure Research Laboratory is developing improved methods for modeling the source through the air pathway to human exposure in significant microenvironments of exposure. As a part of this project, we developed a microscale emission factor model for predicting real-world real-time motor vehicle particulate matter (PM 10 and PM 2.5) (MicroFacPM) emissions, which uses available information on the vehicle fleet composition. This paper the use of MicroFacPM to calculate the contribution of PM 2.5 per vehicle class, age-wise, gasoline, diesel, brake wear and tire wear sources. The contribution of emission factors is presented for two scenarios: first the Tuscarora Mountain Tunnel, on the Pennsylvania Turnpike, PA and second for Capital Boulevard, in Raleigh, NC. In the Tuscarora Tunnel, average contributions of PM 2.5 emission factors were 2.4 percent from 58.7 percent LDGV&T, 2.9 percent from 0.4 percent LDDV&T, 0.04 percent from 0.8 percent HDGV, 3.6 percent from 1.5 percent HDDV45, 1.1 percent from 0.9 percent HDDV6, 14.7 percent from 6.5 percent HDDV7, 20.0 percent from 9.4 percent HDDV8A, 5.16 percent from 21.8 percent HDDV8B, and 3.7 percent from tire wear emissions. For the Capital Boulevard, Raleigh, NC, scenario the largest PM 2.5 contribution was from light-duty diesel trucks (37% emissions from 2% vehicles) followed by heavy-duty trucks class 8 (22% from 1% vehicles).
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| PRESENTATION |
Effects of Meteorology on the Transport of Dispersion of Emissions from the Wtc Recovery Site |
08/11/2002
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Huber, A. H., R. C. Gilliam, H. Felngersh, AND R. Kelly. Effects of Meteorology on the Transport of Dispersion of Emissions from the Wtc Recovery Site. Presented at ISEA/ISEE 2002 Conference, Vancouver, Canada, August 11-15, 2002.
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Since September 11, 2001, the EPA National Exposure Research Laboratory (NERL) has applied its meteorological measurements and modeling to support WTC recovery projects. The local meteorology is a key factor in both the diurnal and day-to-day changes in the ambient air concentration levels important to estimating outdoor human exposures. Routine National Weather Service models and measurements of meteorology provide broad coverage over the United States. NERL has a Meteorological Instrumentation Cluster (MIC3) of 3 trailers supporting a portable 10-m tower, a miniSODAR, and a larger SODAR system to vertically profile the site-specific atmospheric winds.
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| PRESENTATION |
Characterizing Meteorology and Air Pollution Dispersion in Urban Environments: A Case Study in New York City Post September 11, 2001 |
05/02/2002
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Huber, A. H., R. C. Gilliam, M. Freeman, R. M. Spencer, H. Felngersh, AND R. Kelly. Characterizing Meteorology and Air Pollution Dispersion in Urban Environments: A Case Study in New York City Post September 11, 2001. Presented at Science Forum 2003, Washington, DC, May 2, 2002.
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There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.
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| PRESENTATION |
Intercomparison of Alternative Vegetation Databases for Regional Air Quality Modeling |
05/20/2002
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Pierce Jr., T. E., J. A. Pleim, E. Kinnee, AND L. Joyce. Intercomparison of Alternative Vegetation Databases for Regional Air Quality Modeling. Presented at AMS 12th Joint Conference with AWMA on Applications of Air Pollution Meteorology, Norfolk, VA, May 20-23, 2002.
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Vegetation cover data are used to characterize several regional air quality modeling processes, including the calculation of heat, moisture, and momentum fluxes with the Mesoscale Meteorological Model (MM5) and the estimate of biogenic volatile organic compound and nitric oxide emissions with the Biogenic Emissions Inventory System (BEIS) [Byun and Ching, 1999]. This paper compares vegetation cover estimated from three contemporary databases: (1) the North American Land Cover Characteristics (NALCC) database, (2) the Biogenic Emissions Landcover Database (BELD3), and (3) the National Land Cover Database (NLCD). Eash of these databases is being used or offers the potential for use with regional-scale air quality models.
This paper has been reviewed in accordance with the U.S. Environmental Protection Agency's peer and administrative review policies. Mention of products or trade names does not constitute endorsement of recommendation of their use.
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| PRESENTATION |
Integration of the Biogenic Emissions Inventory System (Beis3) Into the Community Multiscale Air Quality Modeling System |
05/20/2002
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Pierce Jr., T. E., C. D. Geron, E. Kinnee, AND J. Vukovich. Integration of the Biogenic Emissions Inventory System (Beis3) Into the Community Multiscale Air Quality Modeling System. Presented at 25th Conference on Agricultural and Forest Meteorology, Norfolk, VA, May 20-24, 2002.
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The importance of biogenic emissions for regional air quality modeling is generally recognized [Guenther et al., 2000]. Since the 1980s, biogenic emission estimates have been derived from algorithms such as the Biogenic Emissions Inventory System (BEIS) [Pierce et. al., 1998]. Version 3.10 of BEIS is being implemented as part of an upgrade to EPA's Community Multiscale Air Quality (CMAQ) modeling system. BEIS3.10 contains several improvements over BEIS2: (1) a 1-km vegetation database for the contiguous United States, which resolves forest canopy coverage by tree species; (2) normalized emission factors for 34 chemical species, including 14 monoterpenes: (3) a soil nitric oxide emissions algorithm that accounts for soil moisture, crop canopy coverage, and fertilizer application; and, (4) speciation factors for the CBIV, RADM2, and SAPRC99 chemical mechanisms. The purpose of this paper is to provide preliminary results from BEIS3.10 and to compare volatile organic compound (VOC) and nitric oxide (NO) emission estimates from BEIS2 and BEIS3.
This paper has been reviewed in accordance with the U.S. Environmental Protection Agency's peer and administrative review policies. Mention of products or trade names does not constitute endorsement or recommendation of their use.
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| PRESENTATION |
Photochemical and Aerosol Modeling With the Cmaq Plume-in-Grid Approach |
05/20/2002
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Binkowski, F. S., D. W. Byun, N. V. Gillani, G. L. Gipson, AND J. M. Godowitch. Photochemical and Aerosol Modeling With the Cmaq Plume-in-Grid Approach. Presented at 12th Joint Conference on the Applications of Air Pollution Meteorology with the Air & Waste Management Association, Norfolk, VA, May 20-24, 2002.
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Emissions of nitrogen oxides (NO) and/or sulfur oxides (SO) from individual point sources, such as coal-fired power plants, with tall stacks contribute to reduced air quality. These primary species are important precursors of various oxidant species and secondary fine particulate matter (PM 2.5). In an attempt to provide a more realistic modeling treatment of the dynamic and chemical processes governing pollutants in subgrid scale pollutant plumes emanating from major point sources within an Eulerian 3-D grid modeling framework, a plume-in-grid (PinG) approach was developed and incorporated into the one atmosphere, Community Multiscale Air Quality (CMAQ) modeling system (Byun et.al., 1998). The PinG technique was designed to spatially resolve pollutant plumes and to simulate their gradual growth downwind, which permits photochemical processes in plumes to evolve in a more realistic manner. This paper outline the photochemistry and recently installed aerosol model treatments contained in the CMAQ PinG. Selected results from initial test applications are presented, however, more material will be displayed in the conference poster.
This paper has been reviewed in accordance with the U.S. Environmental Protection Agency's peer and administrative review policies and approved for publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.
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| PRESENTATION |
Urban Morphology for Houston to Drive Models-3/Cmaq at Neighborhood Scales |
05/20/2002
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Ching, J. S., A. Lacser, S. Dupont, AND S. J. Burian. Urban Morphology for Houston to Drive Models-3/Cmaq at Neighborhood Scales. Presented at AMS Symposium on the Urban Environment, Norfolk, VA, May 24-24, 2002.
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Air quality simulation models applied at various horizontal scales require different degrees of treatment in the specifications of the underlying surfaces. As we model neighborhood scales ( 1 km horizontal grid spacing), the representation of urban morphological structures (e.g. building and are distributions, and compositional materials for impervious structures such as roads and parking areas) requires much greater detail. At the neighborhood scale, we expect that the heterogeneities of structures within the urban canopy (i.e., the layer between the surface and the tops of the boundary layer (UBL) wind and thermodynamic structure and a subsequent effect on the pollutant dispersion and flow characteristics and resulting air quality predictions.
The information in this manuscript has been prepared under funding by the United States Environmental Protection Agency. It has been subjected to Agency review and approved for publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.
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| PRESENTATION |
Neighborhood Scale Modeling of PM 2.5 and Air Toxics Concentration Distributions to Drive Human Exposure Models |
05/20/2002
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Ching, J. S., A. Lacser, J. Herwehe, AND D. W. Byun. Neighborhood Scale Modeling of PM 2.5 and Air Toxics Concentration Distributions to Drive Human Exposure Models. Presented at 12th Joint Conference on Air Pollution (AWMA), Norfolk, VA, May 20-24, 2002.
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Air quality (AQ) simulation models provide a basis for implementing the National Ambient Air Quality Standards (NAAQS) and are a tool for performing risk-based assessments and for developing environmental management strategies. Fine particulate matter (PM 2.5), its constituents and size and number distributions, as well as airborne toxic pollutants ("air toxics") have characteristically different degrees of spatial and temporal variability especially in urban areas and in different geographical-climatic regimes. In this study, we explore the specific role of AQ models as a means to drive human exposure models (Burke et al. 2001) and to address situations in which pollutants exhibit high spatial and temporal variability. We seek a capability to capture the resolved-scale concentration fields and to provide measures of sub-grid-scale variability in concentration distributions that impact human exposures. This modeling approach is meant to enhance and complement the more limited data from central site monitoring networks to provide concentration fields at high temporal and spatial resolutions. By providing further information on concentration variability at sub-grid scales, we complete the requirements needed for exposure assessments. The various elements of this modeling approach and some of their specific modeling issues are described.
The information in this manuscript as been prepared under funding by the United States Environmental Protection Agency. It has been subjected to Agency review and approved for publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.
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| PRESENTATION |
Implementation of An Urban Canopy Parameterization in Mm5 |
05/20/2002
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Lacser, A. AND T. L. Otte. Implementation of An Urban Canopy Parameterization in Mm5. Presented at 4th Symposium on the Urban Environment, Norfolk, VA, May 20-24, 2002.
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The Pennsylvania State University/National Center for Atmospheric Research Mesoscale Model (MM5) (Grell et al. 1994) has been modified to include an urban canopy parameterization (UCP) for fine-scale urban simulations (~1-km horizontal grid spacing). The UCP accounts for drag exerted by urban structures, the enhancement of turbulent kinetic energy (TKE) especially near the tops of the buildings, and the modification of the energy budget within the urban canopy (i.e., from the surface to the tops of buildings). This UCP is applied to grid cells in MM5 that have a non-zero fraction of urban land use. This refinement of MM5 is targeted to enable the Community Multiscale Air Quality (CMAQ) Modeling System (Byun and Ching 1999) to capture the details of pollutant spatial distributions in urban areas.
The information in this manuscript has been prepared under funding by the United States Environmental Protection Agency. It has been subjected to Agency review and approved for publication. Mention of trade names or commercial products does not contitute endorsement or recommendation for use.
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| PRESENTATION |
Application of the Models-3 Community Multi-Scale Air Quality (Cmaq) Model System to Sos/Nashville 1999 |
05/20/2002
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Pleim, J. A., F. S. Binkowski, R. L. Dennis, J. M. Godowitch, T. L. Otte, T. E. Pierce, S. J. Roselle, K. L. Schere, J. Young, AND G. L. Gipson. Application of the Models-3 Community Multi-Scale Air Quality (Cmaq) Model System to Sos/Nashville 1999. Presented at 12th Joint Conference on the Applications of Air Pollution Meteorology with the Air & Waste Management Association, Norfolk, VA, May 20-24, 2002.
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The Models-3 Community Multi-scale Air Quality (CMAQ) model, first released by the USEPA in 1999 (Byun and Ching. 1999), continues to be developed and evaluated. The principal components of the CMAQ system include a comprehensive emission processor known as the Sparse Matrix Operator Kernel for Emissions (SMOKE), a Chemical Transport Model (CTM), and a meteorology model, the Penn State/NCAR Mesoscale Model (MM5). Evaluation of the CMAQ modeling system includes simulation of a series of air quality field studies such as NARSTO and SOS. This paper describes many upgrades to the next release (June 2002) of the CMAQ system and our initial model application to the SOS/Nashville 1999 field experiment.
This paper has been reviewed in accordance with the U.S. Environmental Protection Agency's peer and administrative review policies and approged for presentation and publication.
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| PRESENTATION |
Implementation of An Urban Canopy Parameterization for Fine-Scale Simulations |
06/24/2002
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Otte, T. L. AND A. Lacser. Implementation of An Urban Canopy Parameterization for Fine-Scale Simulations. Presented at National Center for Atmospheric Research, Boulder, CO, June 24-28, 2002.
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The Pennsylvania State University/National Center for Atmospheric Research Mesoscale Model (MM5) (Grell et al. 1994) has been modified to include an urban canopy parameterization (UCP) for fine-scale urban simulations ( 1 - km horizontal grid spacing ). The UCP accounts for drag exerted by urban structures, the enhancement of turbulent kinetic energy (TKE) especially near the tops of the buildings, and the modification of the energy budget within the urban canopy (i.e., from the surface to the tops of buildings). This UCP is applied to grid cells in MM5 that have an non-zero fraction of urban land use. This refinement of MM5 is targeted to enable the Community Multiscale Air Quality (CMAQ) Modeling System (Byun and Ching 1999) to capture the details of pollutant spatial distributions in urban areas. Preliminary results will be presented below.
The information in this manuscript has been prepared under funding by the United States Environmental Protection Agency. It has been subjected to Agency review and approved for publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.
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| PRESENTATION |
Cooperative Research and Development for Application of Cfd to Estimating Human Exposures to Environmental Pollutants |
06/10/2002
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Huber, A. H., M. Freeman, K. H. Kuehlert, AND W. Schwarz. Cooperative Research and Development for Application of Cfd to Estimating Human Exposures to Environmental Pollutants. Presented at 2002 Fluent Users' Group Meeting, Manchester, NH, June 10-12, 2002.
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Under a Cooperative Research and Development Agreement (CRADA), Fluent, Inc. and the US EPA National Exposure Research Laboratory (NERL) propose to improve the ability of environmental scientists to use computer modeling for environmental exposure to air pollutants in human exposure microenvironments. There is an ever-growing need for reliable tools that can assess human exposure to environmental pollutants. In recent years, Computational Fluid Dynamics (CFD) modeling has emerged as a promising technology for such assessment. CFD has the potential to yield more accurate solutions than other methodologies. Implementing CFD yields better predictions, because CFD is based on fundamental physics, on the effects of detailed three-dimensional geometry, and on local environmental conditions.
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| PRESENTATION |
Comparison of Alternative Vegetation Databases for Regional Air Quality Modeling |
05/22/2002
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Pierce Jr., T. E., J. A. Pleim, E. Kinnee, AND L. Joyce. Comparison of Alternative Vegetation Databases for Regional Air Quality Modeling. Presented at 12th AMS/AWMA Conference on Applications of Air Pollution Meteorology, Norfolk, VA, May 22, 2002.
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There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.
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| PRESENTATION |
Observations of Similarity Theory Stability Correction Terms for Momentum and Temperature, Over Agricultural Fields and Forests. |
05/20/2002
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Finkelstein, P. L. Observations of Similarity Theory Stability Correction Terms for Momentum and Temperature, Over Agricultural Fields and Forests. Presented at 25th Agricultural and Forest Meteorology Conference, Norfolk, VA, May 20-24, 2002.
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Many observations of temperature and wind speed profiles have been taken over "ideal" terrain and analyzed to develop the stability correction terms which are commonly used in the application of similarity theory. Fewer observations have been taken and analyzed in this manner over more "real world" conditions. In this study four extensive data sets from recently completed field studies of atmospheric deposition are used to derive values of the stability correction terms. Observations were made over a corn field, a soybean field, a deciduous forest, and a mixed deciduous - coniferous forest. Because observations of effective surface temperature were not available, Psi-T is presented as it would be used to estimate differences in temperature between two levels in the atmosphere. Similarities and differences in the observations as a function of site, stability, and other variables are presented and discussed. Comparisons are made to published models. Points of agreement and disagreement are noted and discussed.
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| PRESENTATION |
A Regional Model for Pcdd/F's Based on a Photochemical Model for Air Quality and Particulate Matter |
12/06/2002
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Hutzell, W. T. A Regional Model for Pcdd/F's Based on a Photochemical Model for Air Quality and Particulate Matter. Presented at Special Session on Air Toxics American Geophysical Union, San Francisco, CA, December 6-10, 2002.
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How important is gas to particle partitioning in predicting air concentrations and deposition of Poly-Chlorinated Dibenzo-p-Dioxins and Furans (PCDD/F's)? Literature indicates that the fate of emissions changes because the summation of atmospheric processes has a different balance. Dry deposition decreases if fine particulate matter uptakes the compounds but it increases if coarse and larger particulates provide a large amount of particulate mass. Wet deposition increases, as sorption to particulate matter increases, but increased wet deposition is episodic. Competing effects then make difficult assessing how important gas to particle partitioning is at predicting air concentration and deposition. This presentation explores an answer to the question by using a regional model for air quality and particulate matter. The model uses a continental domain and a simulation period from one to two months. Both facilitate investigating compounds that undergo long-range transport such as PCDD's and PCDF's. To illustrate the above effects, deposition and transport changes are shown for congeners with differing volatility. Additional evaluation compares observed air concentrations to model predictions.
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| PRESENTATION |
Meteorological Measurements and Modeling in Support of Human Exposure Modeling Microenvironmental Factors |
02/25/2002
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Meteorological Measurements and Modeling in Support of Human Exposure Modeling Microenvironmental Factors. Presented at CRC Workshop on Air Toxics Modeling, Woodlands, TX, February 25-26, 2002.
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There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.
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