Formation of Winter Surface Temperature Anomalies in the North Atlantic in Decades of Negative and Positive Values of the North Atlantic Oscillation Index

Abstract An analysis of the variability of the winter surface temperature anomaly in the North Atlantic in decades of negative and positive values of the North Atlantic Oscillation Index is presented. It is found that, in a decade with negative values of the North Atlantic Oscillation Index, the slope waters of the Gulf Stream system and Labrador Current waters decrease the temperature of the Gulf Stream at the mixing zone on the Scotia Peninsula shelf and in the area of the quasi-stationary anticyclonic gyre to a maximum. In a decade with positive values of the North Atlantic Oscillation Index, the temperature of the slope waters is close to the climate normal. Taking into account the increased speed of the Gulf Stream in the years with positive values of the North Atlantic Oscillation Index, the spreading of the ocean surface temperature anomaly over the North Atlantic water area occurs for a shorter time than in the years with negative values.