Tom Trull – IMAS

Date:  Friday, 15 June 2012, 4:00 PM
Venue:  IMAS Seminar room

Abstract:
The Southern Ocean is a strangely special place.  Biological productivity is severely limited by the lack of one of the most abundant elements on Earth – Iron.  The deficiency was suspected in the 1930’s, but not until the 1980’s could the sub-parts per billion levels be determined.  In 1999, an iron addition experiment produced a phytoplankton bloom that became the first man-made marine object visible from space – showing that even in the low light and cold phytoplankton respond to iron supply and take up CO2.  This response contributes to the magnitude of glacial-interglacial climate variations and will influence future ocean CO2 uptake.  That uptake increases acidity, which appears to be already altering ocean ecosystems. Quantifying the coupling of Fe and CO2 and the impacts of acidity is proving to be complex and regionally variable.