The Source and Fate of Primary Production in Relation to Carbon Fluxes on NOAA's Long Line Cruises

Francisco P. Chavez, Reiko Michisaki, Kurt Buck

N93S : North Atlantic Summer 1993

Seasonal composite of chlorophyll for the Summer, 1993
from the Coastal Zone Color Scanner (CZCS 53k).

This cruise supports research funded by the NOAA Climate and Global Change Program under the Ocean-Atmosphere Carbon Exchange Study (OACES) and the Radiatively Important Trace Species (RITS) component of the Atmospheric Core Project. The goal of the OACES project is to determine the source and sink regions of CO2 in the Equatorial and North Atlantic during the summer. Baseline of total carbon inventory in this region was established such that the uptake rate of atmospheric CO2 can be determined for future cruises. Our contribution to this project was to enhance the observations relevant to climate and global change with measurements of primary and new production in an attempt to quantify the effects of the biological system on the carbon and nitrogen cycle.

The cruise took place aboard the NOAA research vessel R/V MALCOLM BALDRIGE and occurred between July 7 - August 28, 1993. There were three legs to the cruise of which the data submitted in this report encompasses only Legs 1 and 2. Cruise tracks and station locations are shown in Figure 1. Leg 1 departed from Fortaleza, Brazil and began sampling on July 7 at 5°S, 25°W with 0.5° station spacing between 5°S and 5°N and 1° spacing afterwards. Kevlar stations were 5° apart. Leg 1 ended in Funchal, Madeiras on August 15. Leg 2 began in Madeira, Portugal on August 18 and ended in Reykjavik, Iceland on August 28. CTD stations on Leg 2 were 1° apart.

An underway mapping system was deployed, providing a continuous record of fluorescence, PAR, GPS positions, and nitrate. Data from this cruise was collect and processed by personnel from the Monterey Bay Aquarium Research Institute (MBARI) and NOAA.

Next: Methods and Materials