Enhanced concentrations of dissolved gaseous mercury in the surface waters of the Arctic Ocean

• During an almost three months long expedition in the Arctic Ocean, the Beringia 2005, dissolved gaseous mercury (DGM) was measured continuously in the surface water. The DGM concentration was measured using an equilibrium system, i.e. the DGM in the water phase equilibrated with a stream of gas and the gas was thereafter analysed with respect to its mercury content. The DGM concentrations were calculated using the following equation, DGM = Hg eq / k H' where Hg eq is the equilibrated concentration of elemental mercury in the gas phase and k H' is the dimensionless Henry's law constant at desired temperature and salinity. During the expedition several features were observed. For example, enhanced DGM concentration was measured underneath the ice which may indicate that the sea ice acted as a barrier for evasion of mercury from the Arctic Ocean to the atmosphere. Furthermore, elevated DGM concentrations were observed in water that might have originated from river discharge. The gas-exchange of mercury between the ocean and the atmosphere was calculated in the open water and both deposition and evasion were observed. The measurements showed significantly enhanced DGM concentrations, compared to more southern latitudes. © 2008 Elsevier B.V. All rights reserved.

Ämnesord

NATURVETENSKAP  -- Geovetenskap och miljövetenskap -- Oceanografi, hydrologi och vattenresurser (hsv//swe)

NATURAL SCIENCES  -- Earth and Related Environmental Sciences -- Oceanography, Hydrology and Water Resources (hsv//eng)

NATURVETENSKAP  -- Kemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences (hsv//eng)

Nyckelord

gas-exchange

mediterranean sea

humic substances

time-series

elemental mercury

coastal seawater

atmospheric mercury

atlantic-ocean

air

springtime depletion

atmospheric mercury

springtime depletion

mediterranean sea

elemental mercury

humic substances

coastal seawater

atlantic-ocean

gas-exchange

time-series

air

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art (ämneskategori)

ref (ämneskategori)