Variations in the ice cover of the Arctic Basin in the 21st century based on model simulations: Estimates of the perspectives of the Northern Sea Route

Trends in variations of the ice cover of the ArcticBasin were analyzed based on the daily data of simula-tions for the 21st century to estimate possible perspec-tives of the Northern Sea Route. Numerical simulationsusing the coupled atmosphere–ocean general circula-tion model (AOGCM) ECHAM5/MPI-OM were usedin the analysis [1, 2] under a sufficiently aggressiveSRES-A2 scenario [3] of anthropogenic emission ofgreenhouse gases into the atmosphere.Variation in the sea ice area in the Arctic Ocean isone of the key factors and indicators of climaticchanges in the Arctic. The processes of ice formationand melting are related to a number of physical factors.Ice formation depends not only on the meteorologicalfactors that influence cooling of the ocean, but also onthe characteristics of the upper ocean layer, in particu-lar its temperature, salinity, and thickness. A transitionfrom the ice-free regime to the ice regime is related tothe reconstruction of the vertical structure of the oce-anic layer with the formation of a halocline, which lim-its significantly the vertical exchange [4].According to the satellite data (see, for example,http://nsidc.org), since the end of the 1970s, the mini-mal area of sea ice in the Arctic basin in Septemberdecreased annually by 60000 km