Calcite Concentration, Calcification, and Photosynthesis Measured during the U.S. JGOFS Arabian Sea Process Study

A component of U.S. Joint Global Ocean Flux Study (JGOFS) is the
Arabian Sea Process Study. Eleven cruises took place aboard the R/V
Thomas G. Thompson for about sixteen months from October 1994 until
January 1996. These cruises provided seasonal coverage of the annual
monsoon and inter-monsoon cycles in the area southeast of Oman - from
where the cruises were staged. The monsoons of the Arabian Sea drive
a uniquely intense carbon cycling system, and it is the goal of JGOFS
to better understand the role of the oceans in global carbon cycling.

Suspended calcite concentration (CaCO3), calcification rate, and
photosynthesis rate were measured from water samples collected at
various depths on cruises TTN-049 and TTN-053. The water samples were
incubated with carbon-14, a radioactive label to measure the
production of calcite by coccolithophores. After incubation, the
water samples were filtered, and radioactivity was measured to
determine the carbon-14 fixation rate.

Photosynthesis was measured by rate of carbon-14 fixation on the
organic fraction of the filtrate.

Calcification was measured by rate of carbon-14 fixation on the
calcite fraction of the filtrate.

Suspended calcite concentration was measured as calcium concentration
for particles greater than 0.4 microns.

The data is public domain and can be retrieved on-line at
"http://usjgofs.whoi.edu/jg/dir/jgofs/"

[This information was obtained from U.S. JGOFS website at WHOI.]