Towards Synoptic Estimates of the Metabolic Status of the North Atlantic Subtropical Gyre
Dall'Olmo, Giorgio; Artioli, Yuri; Polimene, Luca
Plymouth Marine Laboratory, UNITED KINGDOM

Carbon loss rates are one of the important unknowns in the ocean carbon cycle. Large uncertainties remain especially in oligotrophic subtropical gyres, which are considered net sources of CO2 by some authors or systems in near balance by others. In-situ climatologies of pCO2, sea-surface temperature, salinity, and mixed-layer depth were exploited to derive the concentration of dissolved inorganic carbon (DIC) in the north Atlantic subtropical gyre. By accounting for air-sea exchange, net primary production, and vertical mixing, the contribution of heterotrophic respiration to variations in DIC was then estimated. Preliminary results highlighting the potential and drawbacks of this approach will be presented and discussed.