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

The Equatorial Pacific Process Study (EQPAC) was conducted along 140 deg W
longitude during 1992.

Four cruises took place: February 3 - March 9, March 19 - April 15,
August 5 - September 18, and September 24 - October 21. A fifth benthic
cruise and sediment trap legs were added. During the first cruise
(TT007), 15 stations were occupied along 140 deg W longitude from
12 deg N latitude to 12 deg S latitude. During the second cruise
(TT008), data were collected at 8 stations along 140 deg W longitude
from 9 deg S latitude to 9 deg N latitude. During the third cruise
(TT011), data were collected at 15 stations along 140 deg W from 12 deg N
latitude to 12 deg S latitude. 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
"http://usjgofs.whoi.edu/jg/dir/jgofs/"

[The information in this summary was taken from the JGOFS
World Wide Web pages.]