Interannual variability of the upper ocean carbon cycle in the northeast Atlantic Ocean

Abstract

Surface waters in the subtropical gyres have persistently absorbed anthropogenic CO2 at a rate such that their inorganic carbon concentrations have shown a clear upward trend. We report a 10-year time series of upper-ocean inorganic carbon observations from the northeastern subtropical Atlantic at ESTOC which indicates significant variability in the inorganic carbon fluxes produced by variations in the Winter mixed-layer depths, induced by sea surface temperature anomalies. This variability reflects fluctuations relating to the NAO for both sites of the sub-tropical gyre, with the Eastern part showing a closer correlation with a 3-year NAO delay. The response to interannual variations in the meteorological forcing to the extra-tropical carbon cycle can be predicted to clarify effects on future climate change. Copyright 2007 by the American Geophysical Union.