Time dependence of average regional sulfur oxide concentrations

The atmospheric burden of SO/sub 2/ and SO/sub 4/ in a large regional area has been calculated as a function of time during the July 1978 SURE intensive period. A formulism is developed in which a highly parameterized description of deposition and chemical conversion is combined with a realistic emissions inventory and with realistic trajectories as calculated with the BNL long-range air quality model, AIRSOX. Temporal variations in the regional atmospheric burden are calculated as being due to variations in the advection of material through the region, with the pollutant being advected having a characteristic half-life for its formation and decay. The calculated atmospheric burdens are divided by a nominal mixing height to derive an average ground-level concentration. Comparison is made with the corresponding concentrations derived from SURE observations. The regions for which these comparisons have been made are in the Midwest and East and are similar in size (approx. 5 x 10/sup 5/ KM/sup 2/) and location to areas commonly affected by regional sulfate episodes