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

 
BIOGENIC SOURCES OF SULFUR IN THE ARCTIC
 
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