Interannual variability of sea surface temperature at the polar latitudes of the Atlantic Ocean

Abstract

The general regularities and regional differences in the interannual variability of the sea surface temperature in the polar latitudes of the Atlantic Ocean are revealed according to the OI SST reanalysis data for period 1982—2017. The reanalysis contains daily average sea surface temperature values at the nodes of a regular grid 0,25°×0,25°. In this work, areas where the ice concentration did not exceed 90 % were analyzed. In both polar basins, the position of areas with a high level of sea surface temperature interannual variability qualitatively coincides with the position of intense currents. The maximum values of linear sea surface temperature trends are observed in areas of the maximum level of interannual variability, while the trends in long-term sea surface temperature variability in the Arctic and Antarctic are noticeably different. Significant positive sea surface temperature trends prevail in the Atlantic sector of the Arctic. Significant negative trends have been identified only off the northeastern coast of Greenland and north of the Arctic Current. The sea surface temperature decrease on a long-term scale in this area is associated with an increase of cold water transport by the East Greenland and Arctic currents, which are formed as a result of the intensive melting of Arctic ice observed in recent decades. In the Atlantic sector of the Antarctic, on the contrary, significant negative sea surface temperature trends prevail. In the Arctic, the maximum values of positive sea surface temperature trends are observed in August—September during the period of maximum warming of surface waters and minimum concentration of drifting ice. In the Antarctic, the maximum negative sea surface temperature trends in absolute value are observed from August to October, during the period of surface water cooling and maximum ice concentration.