Processes Determining Synchronous Interdecadal Variability of Surface Temperature in the Barents and Black Seas

Purpose. The work is devoted to considering the phase correspondence between the interdecadal variability of the North Atlantic Oscillation and the Atlantic Multidecadal Oscillation indices, and their influence on the mechanism of synchronous formation of the surface temperature anomalies in the Barents and Black seas. Methods and Results. The surface temperature anomaly values in the Barents and Black seas selected from the Hadley Centre for Climate Prediction and Research arrays, namely the sea ice and sea surface temperature data set, were used. To assess the atmospheric circulation in the Atlantic-European sector, the North Atlantic Oscillation and Atlantic Multidecadal Oscillation indices, as well as the position of the tropospheric frontal zone were applied. The correlation between the position of the tropospheric frontal zone and the values of the North Atlantic Oscillation index was analyzed using the initial series smoothed by a filter of a moving average, and spatial distribution of the surface temperature anomalies - by the composite maps. At the negative values of the Atlantic Multidecadal Oscillation (1950-1970), the processes characteristic of the negative values of the North Atlantic Oscillation index were predominant, whereas at the positive values of the Atlantic Multidecadal Oscillation index (1970-1990), the processes characteristic of the positive values of the North Atlantic Oscillation index prevailed. Conclusions. The atmospheric circulation in the Atlantic-European sector constitutes the basic mechanism regulating the sea surface temperature anomalies in the North Atlantic, as well as in the Barents and Black seas. At the positive values of the North Atlantic Oscillation index, the sea surface temperature in the Barents Sea became higher, and that of the Black Sea - lower than the climate mean. At the negative values of the North Atlantic Oscillation index, the sea surface temperature in the Barents Sea became lower, and that of the Black Sea - higher relative to the climate mean.