Transpolar Drift

In certain regions, the transport and the distribution carried out by sea ice are important processes. This is especially true for the Arctic Ocean where specific processes in the shallow coastal areas of the Eurasian shelf induce the ice, in the course of its formation, to incorporate sediment material from the ocean floor and the water column. The Transpolar Drift distributes the sediment material across the Arctic Ocean all the way to the North Atlantic. Glacio-marine sedimentation covers one-fifth of present day s ocean floor (Lisitzin 1996). 

In surface current systems away from the continents, Ra becomes a powerful tracer for waters that have been in contact with the continental shelf. The Ra enrichment in surface waters in the equatorial Pacific point to shelf sources off New Guinea, from where the isotope is carried eastward in the North Equatorial Counter Current. In this plume, the vertical distribution of the isotope has been used to derive vertical mixing rates. A very high accumulation of Ra is observed in the transpolar drift in the central Arctic Ocean, a signal derived from the extensive Siberian shelves. 

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