Record Display for the EPA National Library Catalog


Main Title Interpretive Analysis of Observed and Modeled Mesoscale Ozone Photochemistry in Areas with Numerous Point Sources.
Author Pleim, J. E. ; Ching, J. K. S. ;
CORP Author National Oceanic and Atmospheric Administration, Research Triangle Park, NC. Atmospheric Sciences Modeling Div.;Environmental Protection Agency, Research Triangle Park, NC. Atmospheric Research and Exposure Assessment Lab.
Publisher c1993
Year Published 1993
Report Number EPA/600/J-93/264;
Stock Number PB93-212702
Additional Subjects Ozone ; Point sources ; Photochemical reactions ; Nitrogen oxides ; Hydrogen compounds ; Computerized simulation ; Air pollution ; Atmospheric chemistry ; Photochemistry ; Flow models ; Reprints ; RADM(Regional Acid Deposition Model) ; Volatile organic compounds
Library Call Number Additional Info Location Last
NTIS  PB93-212702 Some EPA libraries have a fiche copy filed under the call number shown. 07/26/2022
Collation 19p
The Regional Acid Deposition Model (RADM) has been applied to several of the field experiments that were part of the Acid Models Operational and Diagnostic Evaluation Study (Acid MODES) to assess the model's ability to simulate photochemical production of ozone in regions dominated by point source emissions. The comparison of model simulations at different grid resolutions suggests that increased resolution improves the simulation of ozone photochemistry in such regions. Further analysis of NOx, and HOx concentrations and photochemical production rates of ozone, however, show that the model's response to large point source emissions is very unsystematic both spatially and temporally. This is due to the models inability to realistically simulate the small scale (subgrid) gradients in precursor concentrations in and around large point source plumes. Because of the inherently nonlinear nature of ozone photochemistry with respect to concentrations of NOx and VOC, ozone formation rates in model grid cells depend enormously on grid resolution, dispersion rates (primarily wind speed and mixed layer height), chemical background (VOCs and radicals) and NOx emission rates.