Seasonal distributions of the coccolithophore, Emiliania huxleyi, and of particulate inorganic carbon in surface waters of the Scotia Sea

Data on the surface distributions of chlorophyll, particulate inorganic carbon, biogenic silica and coccolithophores for a section in the western Scotia Sea (Drake Passage) made in December 2006 are presented. The relationships between PIC, total coccoliths and water-leaving radiance (as measured by MODIS) are largely consistent with published observations for warmer waters. However, for water temperatures < 4 °C, the estimated values of PIC per coccolith are relatively low. Examination of satellite images of the Scotia Sea for the austral summer 2006/7 and for mid-January 2003 to 2008 indicates considerable temporal (seasonal and interannual) variability in the surface distribution of PIC. Physical processes (advection and cross-frontal exchange) appear to be important in determining year-to-year differences. Current satellite algorithms may give significant overestimates of coccolith PIC for the colder waters of the Southern Ocean.