9419418 Sievering This project is part of the Southern Hemisphere Marine Aerosol Characterization Experiment (ACE-1), which will be conducted in the remote Southern Pacific in 1995 using aircraft, ship-board, and ground-based measurements of a wide variety of chemical species, physical and meteorological parameters with the central goal of investigating the formation, evolution, and optical properties of atmospheric aerosol. In this component, the role of non-sea-salt sulfate production from the oxidation of sulfur dioxide by ozone in sea-salt aerosol water will be investigated. Aerosol particle samples will be obtained with a high-volume cascade impactor at Cape Grim, Australia and aboard the research vessel Discoverer during the ACE-1 intensives, as well as during ship transit from Seattle, WA, to Tasmania. Ion chromatography analysis for anions and cations from aerosols collected in the different stages of the impactor, along with complementary data on the water associated with size fractions of the sea-salt particle mode, sulfur dioxide, ozone, and other ambient air concentrations as well as meteorological parameters will provide the necessary data for a comparison of observed and model predicted non-sea-salt sulfate in several sea-salt mode size fractions. These data, along with their interpretation, will also provide an estimate of the contribution that this mechanism of sulfur dioxide oxidation makes to sulfur dioxide loss rates as well as the total sulfur budget in the marine boundary layer.
