The sea surface CO 2 fugacity and its relationship with environmental parameters in the subpolar North Atlantic 2005

• Main Authors: Olsen, A., Brown, K. R., Chierici, M., Johannessen, T., Neill, C.
• Other Authors: Bjerknes Centre for Climate Research (BCCR), Department of Biological Sciences Bergen (BIO / UiB), University of Bergen (UiB)-University of Bergen (UiB), Geophysical Institute Bergen (GFI / BiU), University of Bergen (UiB), Marine Chemistry, Department of Chemistry
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2007
• Subjects: [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO]; [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph]; [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces; environment; [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; [SDU.STU]Sciences of the Universe [physics]/Earth Sciences; Greenland; North Atlantic
• Online Access: https://hal.science/hal-00297897; https://hal.science/hal-00297897/document; https://hal.science/hal-00297897/file/bgd-4-1737-2007.pdf

International audience We present the first year-long subpolar transatlantic 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 the shelves the f CO 2 sw goes through a pronounced seasonal cycle. Surface waters are saturated to slightly supersaturated over a wide range of temperatures in winter. 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, and f CO 2 sw is correlated to both of these through exponential decay and growth curves, respectively. In particular, MLD appears to be able to predict open ocean subpolar f CO 2 sw to within 12 ?atm using a single equation for the whole year. The predictive capability of chl a is around 20% less, with root mean square values of 14.5 ?atm. As f CO 2 sw extrapolation parameters, both MLD and chl a outperform sea surface temperatures in the open subpolar North Atlantic. However, the situation on the shelves is much more heterogeneous and the f CO 2 sw ?parameter relationships are not as strong as they are off the shelves.