Trends in the Sea Surface Temperature in the Sea of Okhotsk and Adjacent Basins Based on the Satellite Data in 1998–2017

Abstract

Time series of monthly mean sea surface temperatures in the Sea of Okhotsk and adjacent basins have been formed from 20-year-long satellite measurements (1998–2017). Coefficients of the linear trend are determined in each spatial cell with a size of 2 × 2 km using the method of least squares. Such coefficients are calculated for each month separately, for the annual mean values, and for seasonally average values of the temperature. The relationship of these coefficients with the observed decrease in the ice cover in the Sea of Okhotsk in the last 20 years has been analyzed. It is shown that the temperature of the surface layer in this basin decreases; the most significant decrease is observed in its northern and western parts. This trend is especially pronounced in the spring, which may be due to a decrease in the ice cover and stronger water cooling due to the winter convection when the area of ice cover decreases.