Description
Summary:International audience We present the first year-long subpolar trans-Atlantic set of surface seawater CO 2 fugacity ( f CO 2 sw ) data. The data were obtained aboard the MV Nuka Arctica in 2005 and provide a quasi-continuous picture of the f CO 2 sw variability between Denmark and Greenland. Complementary real-time high-resolution data of surface chlorophyll- a (chl- a ) concentrations and mixed layer depth (MLD) estimates have been collocated with the f CO 2 sw data. Off-shelf f CO 2 sw data exhibit a pronounced seasonal cycle. In winter, surface waters are saturated to slightly supersaturated over a wide range of temperatures. Through spring and summer, f CO 2 sw decreases by approximately 60 ?atm, due to biological carbon consumption, which is not fully counteracted by the f CO 2 sw increase due to summer warming. The changes are synchronous with changes in chl- a concentrations and MLD, both of which are exponentially correlated with f CO 2 sw in off-shelf regions.