Connection of Autumn North Asian Snow with Mid-winter Tibetan Plateau Snow

Abstract

The Tibetan Plateau (TP) snow variability is attracting growing interest, while its causes are not yet fully clear. In this study, the potential link of Eurasian snow with TP snow is detected. Excessive October–November (ON) north Asian snow cover can boost the upward wave activity and thus heat the stratospheric polar atmosphere, which subsequently gives rise to an attenuated stratospheric polar vortex (SPV). Meantime, the downward propagation of this SPV anomaly in boreal winter when the troposphere–stratosphere interaction is active induces an anomalous horizontal wave train in the middle troposphere. Such a wave train generates an anomalous anticyclone around the TP, facilitating the decreased local snowfall and snow depth in January. These processes indicate a connection of the mid-latitude Asia–Arctic–TP via the vertical and horizontal wave activity and effectively supply a predictive indicator for the mid-winter TP snow depth.