Natural Iron Fertilization of the Southern Ocean from Melting Sea-ice

Old Dominion University Research Foundation, Norfolk VA

Investigators

Abstract

01-29814 Edwards The proposed project is a Small Grant for Exploratory Research (SGER) which will take advantage of a cruise of the Australian icebreaker RSV Aurora Australis in October 2001 to investigate the concentration of biologically active iron in the sea ice and its snow cover. Sea ice acts as a natural depository for wind-borne dust, but there is currently no reliable information on the magnitude of this source of iron for the production of phytoplankton in the upper layers of the Southern Ocean. Simple flux calculations suggest that this may be the dominant source, and up to three times as large as all other sources combined. The objective of this research is to evaluate both the concentration and bioavailability of iron in the seasonal sea ice of the Southern Ocean south of Australia. Sample data, when combined with other sea ice observations and sea ice drift models will greatly enhance our knowledge of antarctic iron biogeochemistry. ***