Measurement and interpretation of acidity in Southern California rainfall and aerosols

Abstract

The long-term goal of this work is to assess the environmental significance of acidity transport in the Southern California region. There are three potentially important transport routes: wet flux of acidity to the surface of the basin; dry flux of acidity as aerosol deposition; absorption of acidic and basic gases at the basin surface. We view the research from two perspectives: (1) the overall mass balance aspect of sources and sinks for various acids and bases (nitric acid, sulfuric acid, ammonia, organic acids, etc.) in the basin, and (2) the potential environmental impact of acid components transported via specific routes. The purpose of this research is to understand the transport of acidity in its various physical-chemical forms from energy-related sources to receptors in the Southern California region. The work entails: (a) chemical characterization of rainfall to define kinds and amounts of acid substances present; (b) relationships between air quality and the acid-base chemistry of Southern California rainfall; and (c) the relationships between acid transport and sources of acidity.