Relation of emissions to air quality for photochemical smog

Effective evaluation of air pollution control strategies requires the use of validated and reliable mathemtical models that can relate pollutant emissions to atmospheric air quality. The primary objective of this research program has been to develop a fundamental capability to assess the effectiveness of air pollution control measures in reducing photochemical air pollution. An important aspect of the development has been to simplify the preparation of input data and operational use of the resulting model. The system has been designed to be used by air pollution agencies with relatively little experience in atmospheric physics and chemistry. The assumptions commonly employed in model formulations have been evaluated to ensure a valid representation of the physical and chemical processes in the atmosphere. In the most recent phase of this research the comprehensive photochemical airshed model has been evaluated against data available in the South Coast Air Basin of Southern California. This task was undertaken in collaboration with the California Air Resources Board, Air Quality Modeling Section. A statistical analysis package has been used to evaluate the correspondence of predicted and observed concentrations for the days on which the model was evaluated. An assessment of the EPA ozone isopleth modeling technique has been initiated