On the Mechanism of Arctic Climate Oscillation with a Period of About 15 Years According to Data of the INM RAS Climate Model

Abstract According to data from a preindustrial experiment, a mechanism of Arctic climate oscillation with a period of about 15 years in the INM-CM5 climate model is considered. For this purpose, a technique for computing the contribution of the different components to the generation of oscillation energy and phase variation is used. It is shown that, in the positive phase of an oscillation (the warm Arctic), a negative anomaly of the temperature and salinity occurs at middle latitudes of the North Atlantic. These anomalies are accompanied by a positive North Atlantic Oscillation index. A quarter of the period after Arctic warming, warming and salinization occur at middle latitudes of the North Atlantic. In the Arctic Ocean, the temperature anomalies are generated due to the intensifying advection of the Atlantic water. The evolution of the oscillation phase is accounted for by the heat transport from the Atlantic and the heat flux across the surface. Anomalies of the currents transporting the heat from the Atlantic to the Arctic Ocean are generated mainly by surface wind stress.