This award is for support of a three year project to obtain a long term record of the atmospheric deposition of the marine-derived elements Sulfur, Bromine, Iodine, and Selenium. The principle focus of the work is on the sulfur cycle, because of its role as the major aerosol forming species in the atmosphere and its potential importance in climate regulation. Samples from the Vostok and Taylor Dome ice cores will be analyzed for this study. The ice core record of methansulfonate and non-seasalt sulfate will be extended to include two complete glacial cycles in the deep Vostok ice core and analyses of a shallow, dry drilled ice core from Vostok will allow the identification of any recent changes in these parameters. Analyses of the Taylor glacier ice core will also be made for comparison with Vostok.
