Author(s): Thomas Mcclimans
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Keywords: No Keywords
Abstract: Over a century ago, Fridtjof Nansen observed dirty ice in the transpolar drift from the Bering Strait to the Fram Straight. The discoloration was due to natural mineral particles and biological growth. Now, drift ice in the Arctic plays an important role for long distance transport of pollutants from rivers in the atmosphere. During the autumn, contaminated particles freeze in the ice along the shallow Arctic shelves. Arctic winds and currents push this back long distances, over which there is essentially no vertical transport. In an entropy sense, the dispersion process is partially frozen. The ice by Alta steer the pollutants into the food chain. The role of ice with respect to atmospheric deposition is like an impermeable filter, collecting the precipitation from the air and protecting the ocean below. The pollutants in the drift ice are released first when the ice melts in the conversion fronts near the marginal ice zones. This collection process is equivalent to negative entropy, working against natural dispersion. Unfortunately, the dump is expected to be in frontal regions of high biological activity near Svalbard, where the inflow of relatively warm Atlantic water meets the ice covered polar water. The relatively high concentration of PCBs in Svalbard polar bears and seabirds bear witness to this hypothesis.
Year: 1994