CO2 Exchange Over Sea Ice in the Canadian Arctic
Abstract
Our understanding of the role that atmosphere plays in the seasonally-varying polar marine carbon budget is inadequate, largely because direct measurements of the near-surface atmospheric CO2 flux in this environment are few and far between. During periods of open water and marginal ice cover, the atmosphere and ocean should freely exchange CO2 in response to changing near surface gradients of pCO2. During the winter season however, the sea ice cover should represent a semi-permeable barrier, severely restricting the direct diffusive exchange of gas. Eddy covariance measurements of the atmospheric CO2 flux over seasonal sea ice that were made during the spring season (as part of the C-ICE02 experiment in the central Arctic Archipelago) and in the winter (the over-winter phase of the 2004 Canadian Arctic Shelf Exchange Study near to Amundsen Gulf), support this supposition. However, we have observed, and will report on, a strong air-ice exchange of CO2 that appears independent of water-column processes, being instead driven by processes originating in the ice volume itself. We believe that this flux is associated with the temperature-brine salinity relationship within the snow and sea ice and that it may: (i) form the basis for an important early spring carbon source to ice biota, and (ii) underpin an important positive climate feedback.
- Publication:
-
AGU Spring Meeting Abstracts
- Pub Date:
- May 2004
- Bibcode:
- 2004AGUSM.C43A..05P
- Keywords:
-
- 1620 Climate dynamics (3309);
- 3339 Ocean/atmosphere interactions (0312;
- 4504);
- 4207 Arctic and Antarctic oceanography;
- 4540 Ice mechanics and air/sea/ice exchange processes