ANALYSIS OF ICE SITUATION CHANGES ON THE NORTHERN SEA ROUTE IN THE LATE XX - EARLY XXI CENTURY
As global climate changes are becoming a major concern for climatologists and earth scientists, substantial sea ice decline in the Arctic, on the contrary, brings new possibilities for shipping, cargo transportation, and coastal mineral development. Ice cover dynamics in the Russian Arctic in the late XX - early XXI century has been investigated in the paper. On this basis, the aim to assess the prospects for ice situation improvement on the Northern Sea Route during the next decades is set. Thorough analysis of numerous scientific papers addressing this issue reveals that there is a great variety of views and forecasts on this matter. The Arctic ice, as some researchers predict, is expected to completely vanish in the summer months by the middle of the XXI century, however other insights suggest the Arctic climate cooling and subsequent sea ice growth due to the Solar constant lessening by approximately the same time. In this paper, the major factors influencing the Arctic ice dynamics, including the Arctic-North Atlantic water exchange, formation of polynyas around river estuaries, solar activity variations, are considered. The most essential indicators of the ice situation such as the ice extent of the water areas, the average and the maximum ice thickness therein, and the total area of polynyas are investigated. The time series for the above indicators are obtained by use of the ICDC reanalysis data provided by the University of Hamburg.Reanalysis datasets available for 1979-2017 are used to reveal the major trends in the ice situation dynamics for this period. It is shown that the ice cover had been having an overall tendency to decline in the European and the West-Siberian sectors of the Russian Arctic, which in turn had been improved navigability therein. Similar trends are likely to be seen in the next two decades. In the East-Siberian and the Chukchi sectors, the similar dynamics for sea ice decline was obvious until 2007, and then the opposite trend leading to the ice situation aggravation emerged. It is thus feasible to assume that substantial improvement of ice conditions in the East- Siberian and the Chukchi Seas in the summer months is not to be expected in the next decades. Shipping safety therein will remain highly dependent on icebreaker services. It is also quite clear that in the next at least two decades the prospects for opening the transpolar shipping routes will remain illusory, whereas the Northern Sea Route will serve as the main transport artery in the Arctic.