The carbon balance during the 1989 spring bloom in the North Atlantic Ocean, 47°N, 20°W

We report on studies of the carbon balance of the upper water column, done as part of the JGOFS North Atlantic Bloom Experiment, over a 13-day period, at 47°N, 20°W, during the 1989 spring phytoplankton bloom. Gross carbon production was calculated from data on ¹⁸O gross O₂ production and from ¹⁴C production as well. Net carbon production was calculated from net O₂ production rates measured in vitro, as well as from changes in the inventories of nutrients and O₂ along with O₂ evasion rates by gas exchange. Gross carbon production during this period was measured to be 1.83 mol m⁻², and net production was 0.68 mol m⁻². Of this net carbon production, 0.30 mol m⁻² was stored in the euphotic zone as particulate organic carbon, and 0.09 mol m⁻² rained out to depths >150 m. The remainder was remineralized to DIC in the 50–150 m depth interval, with perhaps some DOC storage in the upper 150 m.