Grantee Research Project Results
2000 Progress Report: Development and Evaluation of Modeling Techniques for the Study of Interactions between Urban and Point Source Plumes and Regional Atmospheres in the Formation of Secondary Pollutants
EPA Grant Number: R827028Title: Development and Evaluation of Modeling Techniques for the Study of Interactions between Urban and Point Source Plumes and Regional Atmospheres in the Formation of Secondary Pollutants
Investigators: Odman, Mehmet Talat , McRae, D. Scott
Institution: Georgia Institute of Technology , North Carolina State University
Current Institution: Georgia Institute of Technology
EPA Project Officer: Hahn, Intaek
Project Period: January 15, 1999 through January 14, 2002 (Extended to March 31, 2002)
Project Period Covered by this Report: January 15, 2000 through January 14, 2001
Project Amount: $468,324
RFA: Air Pollution Chemistry and Physics (1998) RFA Text | Recipients Lists
Research Category: Air , Air Quality and Air Toxics , Safer Chemicals
Objective:
The purpose of the study is to develop new modeling techniques and build on existing ones to improve the representation of emission sources in air quality models (AQMs). The interaction of point and urban source plumes with the surrounding atmosphere involves processes of critical importance to the formation, and long-range transport and fate of secondary pollutants such as ozone. Various reactive plume models were imbedded in AQMs to better resolve point source plumes, but no real benefits were reported other than those in the immediate vicinity of the sources. It is suspected that this is due to underestimating the magnitude of numerical diffusion at grid scales where information is typically transferred from the subgrid scale plume model to the grid model. Hand-over criteria will be designed considering chemical state as well as the potential numerical diffusion of the plume. Modeling techniques will be developed that can better resolve urban plumes and provide local grid refinements for a better interface with subgrid scale models.
Progress Summary:
In the second year, we continued the development of criteria for accurate hand-over of information generated by sub-grid scale reactive plume models to regional scale air quality models. Plume distributions generated by the sub-grid models were analyzed using discrete Fourier transforms to obtain the frequency distribution and amplitude of the Fourier components. The transformed frequency distributions then were filtered to reflect the frequencies resolved by the coarser mesh of the regional scale model. An inverse transform of the filtered frequency distributions then is performed. The degree to which the resulting function agrees with the original function gives an indication of the effect of transferring the plume to the coarse grid. Further work remains in generalizing criteria such as the energy ratio and other norm-based metrics.
The concept of an adaptive grid AQM has been fully developed. This concept has been implemented in the Multiscale Air Quality Simulation Platform (MAQSIP). No major data structure changes were necessary. An adaptation module was added that must be called before the science process module for each time step. This module calculates the weight function, computes new grid locations, redistributes the concentration field to new grid locations using advection-interpolation equivalence, and calculates the part of the Jacobian related to adaptive grid transformation and the metrics needed for contravariant velocities. Once the movement tolerance is met, the module processes the meteorology and emissions data for the new grid. The verification of the FORTRAN implementation is underway. For this, we are simulating an ozone episode in the Northern Alabama and Southern Tennessee region during the period of July 7-17, 1995. The meteorological inputs were prepared using a 4x4 km resolution Regional Atmospheric Modeling System (RAMS) run conducted by the Tennessee Valley Authority. The emissions inputs were developed from the Southern Appalachian Mountains Initiative (SAMI) inventory. There are approximately 6,000 major point sources in this domain. For the plume rise calculations, which must be performed in real time, we are using the Emissions-Chemistry Interface Processor (ECIP) for Models-3.
Future Activities:
During the next year we expect to: (1) continue the application of the Fourier transform methodology using plume distributions obtained from SCICHEM and CMAQ-APT; (2) finalize the design of hand-over criteria; (3) complete the verification of the adaptive grid AQM, (4) perform adaptive grid ozone simulations in the Northern Alabama and Southern Tennessee region for the period of July 7-17, 1995, using the meteorological and emissions data prepared; and (5) continue the design of criteria for adaptation for more accurate ozone simulations.
Journal Articles on this Report : 2 Displayed | Download in RIS Format
Other project views: | All 14 publications | 7 publications in selected types | All 4 journal articles |
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Type | Citation | ||
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Srivastava RK, McRae DS, Odman MT. Simulation of a reacting pollutant puff using an adaptive grid algorithm. Journal of Geophysical Research-Atmospheres 2001;106(D20):24245-24257. |
R827028 (2000) R827028 (2001) |
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Srivastava RK, McRae DS, Odman MT. Simulation of dispersion of a power plant plume using an adaptive grid algorithm. Atmospheric Environment 2001;35(28):4801-4818. |
R827028 (2000) R827028 (2001) |
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Supplemental Keywords:
tropospheric, oxidants, nitrogen oxides, mathematics, analytical, Northeast., RFA, Scientific Discipline, Air, Geographic Area, Physics, Environmental Chemistry, Chemistry, mobile sources, tropospheric ozone, Engineering, Chemistry, & Physics, East Coast, air quality standards, fate and transport, Fourier Transform Infrared measurement, urban air, subgrid scale models, air quality models, air modeling, air pollution models, point source effluents, regional atmospheres, troposphere, mathematical formulations, nitrogen removal, urban air , measurement methods , plume dispersion modelsRelevant Websites:
http://environmental.gatech.edu/~odman/ Exit
Progress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.