gyres in the Eurasian Basin, one each in the Amundsen and Nansen Basins, in the model.
5. CONCLUSIONS
The present results are encouraging, and from our first impressions appear to well approximate the fundamental characteristics of the intermediate water circulation, of which the river water appears to be intimately involved. The results also suggest that while there certainly can be considerable modification of the AW by waters entering through the St. Anna and Voronin Troughs, additional mixing may be accomplished further to the east along the Laptev Sea shelf, where waters from all four major Eurasian rivers are injected directly. We also note that the shelf-hugging plumes do not seem to be captured by the Siberian end of the Nansen-Gakkel Ridge, though their presence may be responsible for forcing the Fram Strait waters northward enough so that they are captured by the Nansen-Gakkel Ridge topography, causing them to participate in the Nansen Basin cyclonic circu1ation cell.
Some of the specific physical processes and circulation phenomena that we are currently investigating with regard to these results include: (l) nature of the manner in which the river water interacts with, and modifies the AW; (2) characteristics of the subduction of the primary river waters in the Laptev Sea as a function of the nature of the confluence between them at the surface; (3) nature and sensitivities of the baroclinic/barotropic flow relative strengths, and their impact on the ability of the flow to shift from one ridge location to another (e.g., jump from the Lomonosov Ridge to the Mendeleev), as a function of surface buoyancy and mass f1ux forcings; (4) infulence of the confluence and interactions of the river plumes along the Siberian shelf, and the role of these interactions in causing/allowing Fram Strait water to jump from the continental shelf several hundred kilometers to the Nansen-Gakkel Ridge to form the return branch of the Nansen Basin intermediate water circulation.
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