HR: 0800h
AN: A31B-0843    [Abstracts]
TI: Biogenic Sulphate and Sulphur Dioxide Over the North Atlantic: Spring 2003
AU: * Eaton, S
EM: sarah_eaton@hotmail.com
AF: Memorial University, Earth Sciences, St. John's, NF A1B 3X5 Canada
AU: Burridge, C
EM: ccburridge@hotmail.com
AF: Memorial University, Earth Sciences, St. John's, NF A1B 3X5 Canada
AU: Norman, A
EM: annlisen@phas.ucalgary.ca
AF: The University of Calgary, Physics & Astronomy, Calgary, AB T2N 1N4 Canada
AU: Wadleigh, M A
EM: moire@esd.mun.ca
AF: The University of Calgary, Physics & Astronomy, Calgary, AB T2N 1N4 Canada
AU: Sharma, S
EM: Sangeeta.Sharma@ec.gc.ca
AF: Meteorological Service of Canada, 4905 Dufferin Street, Toronto, ON M3H 5T4 Canada
AU: Leaitch, R
EM: Richard.Leaitch@ec.gc.ca
AF: Meteorological Service of Canada, 4905 Dufferin Street, Toronto, ON M3H 5T4 Canada
AB: Dimethylsulphide (DMS) is released from the ocean surface and is a function of wind speed, photo-oxidation, and phytoplankton productivity. CCN from DMS oxidation are thought to alter the global radiation budget by scattering incoming solar radiation and enhancing cloud albedo. Shipboard measurements of size-segregated and total aerosol sulphate and methanesulphonic acid (MSA) as well as sulphur dioxide from the oxidation of dimethylsulphide (DMS) were measured over the North Atlantic during the spring of 2003. These results are compared to atmospheric DMS concentrations from the same sampling program. Natural sulphur isotope abundance measurements were used to identify the contribution of DMS to sulphur dioxide concentrations since anthropogenic plus volcanogenic and biogenic isotope compositions for this gas are distinct. Unusually light isotope values were found for non sea salt sulphate in all size fractions: a result that has not been described elsewhere for the North Atlantic. These results are compared to MSA and atmospheric DMS concentrations.
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0312 Air/sea constituent fluxes (3339, 4504)
DE: 0315 Biosphere/atmosphere interactions (0426, 1610)
DE: 0322 Constituent sources and sinks
DE: 0330 Geochemical cycles (1030)
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005