High concentrations of both ozone and aerosols are observed over the eastern United States during pollution episodes; they show similar spatial and temporal patterns. Until recently, ozone and aerosols have been treated as separate issues; but recent studies show that they are physically and chemically coupled. Efforts are underway to test the effectiveness of integrated control strategies for ozone and fine particulate matter (PM2.5) reductions. Here, we investigate the impact of reduced sulfur dioxide emissions on ozone production using a Community Multiscale Air Quality (CMAQ) modeling system to simulate the July 12-15, 1995 episode. Neural network models derived from Mie calculations were used to compute aerosol optical properties such as optical depth, single scattering albedo, and asymmetry factor using hourly aerosol volume size distributions and refractive indices predicted by the aerosol module in CMAQ. We included the effects of aerosol scattering on photolysis rates and performed two model runs: one with current sulfur dioxide emissions and one with reduced sulfur dioxide emissions. We will present results from these model simulations and discuss the implications
Symposium on Interdisciplinary Issues in Atmospheric Chemistry