Pacific Decadal Oscillation modulates the Arctic sea-ice loss influence on the midlatitude atmospheric circulation in winter

Abstract. The modulation of the winter impacts Arctic sea-ice loss by Pacific Decadal Oscillation (PDO) is investigated in IPSL-CM6A-LR ocean–atmosphere general circulation model. Ensembles simulations are performed with constrained concentration following Polar Amplification Model Intercomparison Project (PAMIP) and initial conditions sampling warm cold phases PDO. Using a linear model, we estimate simulated impact loss, PDO their combined effects. On one hand, negative North Atlantic (NAO)-like pattern appears response to together modest deepening Aleutian Low. other phase induces large positive Pacific–North America pattern, as well small pattern. Both responses associated weakening poleward flank eddy-driven jet, an intensification subtropical jet stratospheric polar vortex. These effects partly additive; therefore enhances while reduces it. However, also non-additive, interaction between both signals being slightly destructive. This results damping teleconnections under conditions, especially stratosphere. compared those obtained same model atmosphere-only simulations, where does not significantly alter