The Influence of Autumn Eurasian Snow Cover on the Atmospheric Dynamics Anomalies During the Next Winter in INMCM5 Model Data

Abstract

The influence of autumn Eurasian snow cover on the atmospheric dynamics anomalies during the following winter is studied based on the INM RAS climate model data. The North Atlantic Oscillation is the leading pattern that causes the weather and climate variability in the Northern hemisphere. We evaluate the up-to-date model version (INMCM5) ability of the autumn Eurasian snow – winter NAO teleconnection simulation on different timescales. Maximum covariance analysis (MCA) is used to find winter atmospheric signals that are significantly correlated with autumn snow cover anomalies. Using MCA we conclude that Autumn Eurasian snow – winter NAO teleconnection is present in INMCM5 experiments on pre-industrial and present-day climate simulation. However, this method fails to show this phenomenon in experiments on a seasonal timescale. We conduct additional experiments on a seasonal timescale to assess the sensitivity of North Atlantic Oscillation index predictability to initial snow cover perturbations. These experiments demonstrate the absence of direct autumn Eurasian snow impact on the NAO index.