The nature of 60-year oscillations of the Arctic climate according to the data of the INM RAS climate model

Abstract

Abstract Using the data of pre-industrial experiment with the INM-CM5 climate model for the period of 1200 years, we study the mechanism of natural oscillations of Arctic climate with the period of about 60 years. It is shown that for a quarter of the period prior to the Arctic warming there is a flow of Atlantic water into the Arctic ocean (AO) being more intense than usual, the salinity and density are less than usual near the coast and shelf border. As the result of advection of Atlantic water after Arctic warming, the water near the coast and shelf border becomes more salty and heavy, which leads to a weakening of the flow of Atlantic water and the change of oscillation phase. The conclusions are confirmed by calculations of the generation of anomalies of temperature, salinity, and velocity of currents by different terms, as well as estimation of the contribution of various components to the change of oscillation phase.