HR: 1330h
AN: C42A-1015    [PDF]
TI: Global Mercury Pathways in the Arctic Ecosystem
AU: * Lahoutifard, N
EM: Nazafarin.Lahoutifard@science.uottawa.ca
AF: University of Ottawa, Department of Biology, Ottawa, Ontario, Canada, Ottawa, ON K1N 6N5 Canada
AU: Lean, D
EM: dlean@science.uottawa.ca
AF: University of Ottawa, Department of Biology, Ottawa, Ontario, Canada, Ottawa, ON K1N 6N5 Canada
AB: The sudden depletions of atmospheric mercury which occur during the Arctic spring are believed to involve oxidation of gaseous elemental mercury, Hg(0), rendering it less volatile and more soluble. The Hg(II) oxidation product(s) are more susceptible to deposition, consistent with the observation of dramatic increases in snow mercury levels during depletion events. Temporal correlations with ozone depletion events and the proliferation of BrO radicals support the hypothesis that oxidation of Hg(0) occurs in the gas phase and results in its conversion to RGM (Reactive Gaseous Mercury). The mechanisms of Hg(0) oxidation and particularly Hg(II) reduction are as yet unproven. In order to evaluate the feasibility of proposed chemical processes involving mercury in the Arctic atmosphere and its pathway after deposition on the snow from the air, we investigated mercury speciation in air and snow pack at Resolute, Nunavut, Canada (latitude 75$\deg$N) prior to and during snow melt during spring 2003. Quantitative, real-time information on emission, air transport and deposition were combined with experimental studies of the distribution and concentrations of different mercury species, methyl mercury, anions, total organic carbon and total inorganic carbon in snow samples. The effect of solar radiation and photoreductants on mercury in snow samples was also investigated. In this work, we quantify mercury removed from the air, and deposited on the snow and the transformation to inorganic and methyl mercury.
DE: 0365 Troposphere--composition and chemistry
DE: 1610 Atmosphere (0315, 0325)
DE: 1615 Biogeochemical processes (4805)
DE: 9315 Arctic region
SC: Cryosphere [C]
MN: 2003 Fall Meeting