Spring 2008 Seminar Series

Dr. Peter Sedwick

Abstract

The now well-established role of iron in regulating marine primary production mandates the inclusion of iron in conceptual and numerical models of ocean ecology and biogeochemistry.  At present, this task is hindered by our poor knowledge of the distribution of iron in the surface ocean, and of the sources, transformations and sinks that define this distribution.  This point is well demonstrated by the long-running BATS ocean time-series station, for which, until recently, there were no published iron measurements.  In this talk I will discuss new data demonstrating the pronounced impacts of atmospheric input, biological removal, and mesoscale circulation on the distribution of dissolved iron in surface waters of the Sargasso Sea near BATS.  In addition, I will present data concerning the fraction of aerosol iron that dissolves in surface seawater, and argue that anthropogenic emissions may account for a significant fraction of the atmospheric flux of biologically-available iron to the surface ocean.