Increased CO2 uptake due to sea ice growth and decay in the Nordic Seas

• Published in: Journal of Geophysical Research - Oceans Vol. 114; no. C9; pp. C09011 - n/a
• Main Authors: Rysgaard, S., Bendtsen, J., Pedersen, L. T., Ramløv, H., Glud, R. N.
• Format: Journal Article
• Language: English
• Published: Washington, DC American Geophysical Union 01-09-2009; Blackwell Publishing Ltd
• Subjects: Air/sea constituent fluxes; Air/sea interactions; Atmospheric Composition and Structure; Biogeochemical cycles, processes, and modeling; Biogeochemistry; Biogeosciences; carbon uptake; Cryosphere; Earth sciences; Earth, ocean, space; Exact sciences and technology; Nordic Seas; Oceanography; Physical; Sea ice; East Greenland; Arctic region; Atlantic Ocean; Arctic Ocean; polar regions; North Atlantic; Greenland Current; Greenland; carbon uptake; Nordic Seas; sea ice; surface water; models; brines; partial pressure; Summer; growth; melting; carbonates; Dissolved inorganic carbon; export; Uptake
• ISSN: 0148-0227; 2156-2202
• DOI: 10.1029/2008JC005088

The uptake rates of atmospheric CO2 in the Nordic Seas are among the highest in the world's oceans. This has been ascribed mainly to a strong biological drawdown, but chemical processes within the sea ice itself have also been suggested to play a role. The importance of sea ice for the carbon uptake in the Nordic Seas is currently unknown. We present evidence from 50 localities in the Arctic Ocean that dissolved inorganic carbon is rejected together with brine from growing sea ice and that sea ice melting during summer is rich in carbonates. Model calculations show that melting of sea ice exported from the Arctic Ocean into the East Greenland current and the Nordic Seas plays an important and overlooked role in regulating the surface water partial pressure of CO2 and increases the seasonal CO2 uptake in the area by approximately 50%.