Oceanic Primary Production and Chlorophyll Production Measured during the JGOFS Equatorial Pacific Process Study (EQPAC)

During the fourth cruise (TT012), data were collected at 5 stations along 140 deg W longitude from 17 deg S latitude to the equator. At each of the stations, ocean water was sampled at 8 depths down to the 0.1% incident light level using the trace metal (TM) clean rosette. These samples were taken before dawn between 3 and 4 AM.

Carbon-14 solution was added to the samples, and the samples were attached at their appropriate depths on an array line. The array line was attached to a buoy, and the samples were allowed to incubate in situ for 24 hours. After filtering the samples, the filters were placed in scintillation vials, and the activity was counted on a liquid scintillation counter.

Carbon uptake could then be calculated. In addition to primary production (mgC/m^3/day), the following parameters were also measured: primary production integrated to the 1% light level, primary production integrated to the 0.1% light level, chlorophyll-a production (mg/m^3/day), chlorophyll-a production integrated to the 1% light level, chlorophyll-a production integrated to the 0.1% light level, and chlorophyll-a specific production (i.e. mgC/mgChl/day).

The data is public domain and can be retrieved on-line at "usjgofs.whoi.edu/jg/dir/jgofs/" [The information in this summary was taken from the JGOFS World Wide Web pages.]