Balch, W. M.. Bigelow Laboratory for Ocean Sciences, bbalch@bigelow.org
Drapeau, D. M.. Bigelow Laboratory for Ocean Sciences, ddrapeau@bigelow.org
Fritz, J. J.. Smithsonian Environmental Research Center, fritz@serc.si.edu
Ashe, A. L.. Bigelow Laboratory for Ocean Sciences, aashe@bigelow.org
Dunford, S. J.. Bigelow Laboratory for Ocean Sciences,

 
MONSOONAL FORCING OF COCCOLITHOPHORE CALCIFICATION IN THE ARABIAN SEA
 
We summarize results on the changes in coccolithophore calcification and calcium carbonate standing stock associated with the transition from the SW monsoon to the NE monsoon in the Arabian Sea (cruises P4 and P6 of the U.S. JGOFS study, respectively). Mean calcification was ~3X greater during the SW Monsoon than during the NE Monsoon. Calcification per coccolithophore was 7-10X higher and the ratio of calcification to photosynthesis (C/P) was 40-45% higher during the SW Monsoon. The turnover time of particulate inorganic carbon (PIC) was not statistically different between the two cruises (~4.5d averaged over the euphotic zone). The turnover time of particulate organic carbon (POC) increased significantly between P4 and P6 (from ~3d-6d over the euphotic zone). We will discuss vertical sections of coccolithophore abundance, carbon standing stocks and carbon fixation. Coccolithophore calcification was usually about 1-5% of community photosynthesis during both periods. The ratio of calcification to photosynthesis spanned almost 2 orders of magnitude, and was not significantly different from the PIC:POC ratio. We compared surface PIC and POC production rates to sediment trap fluxes from the same region and comment on the fate of this coccolith calcite.
 
Day: Thursday, Feb. 4
Time: Poster
Location: Sweeney Center
 
Code: CS55TH0261S