A decrease in the sink for atmospheric CO2 in the North Atlantic

Global ocean carbon models and available syntheses of the oceanic CO 2 flux suggest that the North Atlantic subpolar gyre (50°N–70°N, 80°W–10°W) is a region of increasing uptake of CO 2 from the atmosphere, with the oceanic partial pressure of CO 2 (pCO 2 ) increasing more slowly than the atmospheric CO 2 over time. Our analysis of available CO 2 data shows that, on the contrary, seawater pCO 2 has increased faster than the atmosphere in recent decades, especially in summer, resulting in a decrease in uptake from the atmosphere. A decrease in the biological productivity of the region may be the underlying cause of this trend. From the observed trend we estimated a significant decrease in the annual carbon uptake in this region.