Levasseur, M. Maurice Lamontagne Institute/Fisheries and Ocean Canada, levasseurm@dfo-mpo.gc.ca
Gosselin, M. Université du Québec à Rimouski, michel_gosselin@uqar.uquebec.ca
Sharma, S. Atmospheric Environment Service/Environment Canada, sangeeta.sharma@ec.gc.ca
Simard, N. Maurice Lamontagne Institute/Fisheries and Oceans Canada, simardn@dfo-mpo.gc.ca
Brickell, P. Atmospheric Environment Service/Environment Canada, peter.brickell@ec.gc.ca
Horner, R. School of Oceanography/University of Washington, rita@ocean.washington.edu
Bates, T. S. NOAA/Pacific Marine Environment Laboratory, bates@pmel.noaa.gc

We investigated the contribution of planktonic and ice microalgae to the production of dimethylsulfoniopropionate (DMSP) and dimethylsulphide (DMS) in the western and central Arctic Ocean during the summer of 1994 Canada/US Arctic Ocean Section. In surface waters, maximum concentrations of particulate DMSP (DMSP-P) (85 nM) and DMS (9.9 nM) were measured in the marginal ice zone of the Chukchi Sea and in leads. A significant positive relationship was found between the abundance of diatoms and DMS levels in these waters. In the ice-covered portion of the section, maximum DMSP-P (1,750 nM) was found in dense algal mats which formed at the ice-water interface, close to the North Pole (88 N). Dissolved DMSP (DMSP-D) and DMS levels were disproportionally low in these mats. DMSP-P and DMSP-D concentrations were very high at the bottom of the ice (up to 527 nM and 728 nM, respectively), with maximum DMS levels of 6.8 nM. DMS levels up to 2 nM were measured in melt ponds which covered up to 13% of the ice pack. Our results stress the potential for DMS production in ice-free Arctic waters and show that leads and melt ponds represent potential sources of sulfur for the Arctic atmosphere.
Day: Friday, Feb. 5
Time: 09:00 - 09:15am
Location: Sweeney Center
Code: SS37FR0900S