This award is for support for a project to develop long-term records of the atmospheric deposition of aerosol-borne, marine- derived elements to the Antarctic ice sheet. The project includes the sampling of Antarctic ice core samples from the Vostok ice core and the laboratory analysis of soluble ions in the ice. The analyses include methanesulfonate, non-sea-salt sulfate, and several additional ions derived from gaseous emissions from the sea surface, from seasalt, and associated with continental dust. The principal emphasis of this work is on sulfur, because of its role as a major aerosol-forming constituent of the atmosphere, and its potential importance to climate. The main goal of the project is to complete analyses of the Vostok ice core.