Тенденции изменения концентрации льда и температуры воздуха в Арктике

Abstract

The article analyses monthly spatial distributions of linear trend coefficients from 1950 to 2019 in the Arctic region using data from the NCEP/NCAR and ERA5 reanalysis on surface air temperature and the HadISST data array on ice concentration. To assess the reliability of the maximum trend values, the observational data in the areas are used. Additionally, the role of the North Atlantic in the air temperature and ice concentration changes in the Arctic region is considered. As a result of the climatic change analysis in the Arctic using different types of reanalysis and observation data, it is revealed that the temperature increases, whereas the ice cover decreases in this region, but it occurs unevenly over the seasons. The maximum values of the air temperature trends are characteristic of the winter period and consistent with the positive NAO trend. Warming is especially pronounced near Spitsbergen Island, Franz Josef Land and the northern part of New Earth Island. According to the observational data and NCEP/NCAR reanalysis, the trends vary from 2 to 2.8°C/10 years, while according to ERA 5, these values are overestimated by about 30%. Intense warming is also observed in October and November in the Beaufort Sea region, according to both NCEP/NCAR and ERA 5 data. Trend values of the air temperature in October and November in these regions from two reanalyses are from 1,8 to 2,4°C/10 years. Both reanalysis overestimate the values compared to the real station data. The maximum ice melting occurs from August to October. At the same time, in September and October the area of the ice cover formation has almost halved in 70 years. In turn, the decrease in ice cover causes a decrease in reflectivity of the underlying Arctic surface, and this is one of the feedback elements in the warming of this region.