Diurnal Cycles of Gaseous Mercury within the Snowpack at Kuujjuarapik/Whapmagoostui, Québec, Canada
- 21 June 2003
- journal article
- Published by American Chemical Society (ACS) in Environmental Science & Technology
- Vol. 37 (15), 3289-3297
- https://doi.org/10.1021/es026242b
Abstract
Mercury is a globally dispersed and toxic pollutant that can be transported far from its emission sources. In polar and subpolar regions, recent research activities have demonstrated its ability to be converted and deposited rapidly onto snow surfaces during the so-known Mercury Depletion Events (MDEs). The fate of mercury once deposited onto snow surfaces is still unclear: a part could be re-emitted to the atmosphere, the other part could contaminate water systems at the snowmelt. Its capacity to transform to more toxic form and to bioaccumulate in the food chain has consequently made mercury a threat for Arctic ecosystems. The snowpack is a medium that greatly interacts with a variety of atmospheric gases. Its role in the understanding of the fate of deposited mercury is crucial though it is poorly understood. In April 2002, we studied an environmental component of mercury, which is interstitial gaseous mercury (IGM) present in the air of the snowpack at Kuujjuarapik/Whapmagoostui (55°N, 77°W), Canada on the east shore of the Hudson Bay. We report here for the first time continuous IGM measurements at various depths inside a seasonal snowpack. IGM concentrations exhibit a well-marked diurnal cycle with uninterrupted events of Hg0 depletion and production within the snowpack. A possible explanation of Hg0 depletion within the snowpack may be Hg0 oxidation processes. Additionally, we assume that the notable production of Hg0 during the daytime may be the results of photoreduction and photoinitiated reduction of Hg(II) complexes. These new observations show that the snowpack plays undoubtedly a role in the global mercury cycle.Keywords
This publication has 40 references indexed in Scilit:
- Size distributions and modal parameters of aerosol constituents in northern Finland during the European Arctic Aerosol StudyJournal of Geophysical Research: Solid Earth, 2002
- Observations of rapid photochemical destruction of ozone in snowpack interstitial airGeophysical Research Letters, 2001
- Evidence of NOx production within or upon ice particles in the Greenland snowpackGeophysical Research Letters, 1999
- Extremely intense whistler mode waves near the bow shock: Geotail observationsJournal of Geophysical Research, 1999
- H2O2 in snow, air and open pore space in firn at Summit, GreenlandGeophysical Research Letters, 1995
- Exposure of James Bay Cree to methylmercury during pregnancy for the years 1983?91Water, Air, & Soil Pollution, 1995
- Exposure of Canadian aboriginal peoples to methylmercuryWater, Air, & Soil Pollution, 1995
- A new sensitive and portable mercury vapor analyzer Gardis-1AWater, Air, & Soil Pollution, 1995
- Sunlight-Induced Formation of Dissolved Gaseous Mercury in Lake WatersEnvironmental Science & Technology, 1994
- Optical properties of snowReviews of Geophysics, 1982