Snowfall Characteristics in Winter over Qinghai-Xizang （Tibetan） Plateau and Its Key Circulation

Based on the meteorological observational data over Qinghai-Xizang （Tibetan） Plateau and atmospheric reanalysis dataset during 1961 to 2020， the snowfall variation characteristics over the Qinghai-Xizang （Tibetan） Plateau and its related corresponding circulation system were analyzed in this paper.Main conclusions are drawn as following： the spatial distribution of snowfall shows a uniformity with less in the northwest and more in the southeast.The characteristics of interannual and interdecadal variability are very evident.The interannual variability of the snowfall over Qinghai-Xizang Plateau was strong.The first mode of Qinghai-Xizang （Tibetan） Plateau snowfall anomalies is regional uniformity.In terms of the key circulation systems that affect Qinghai-Xizang （Tibetan） Plateau snowfall， when the snowfall over Qinghai-Xizang （Tibetan） Tibetan Plateau is more， the upper troposphere corresponds to the positive phase of the southern Eurasian （SEA） teleconnection， characterized as positive anomalies over the southwestern Europe， the Arabian Sea， and the northeast Asia， and negative anomalies over the Middle East and the Qinghai-Xizang （Tibetan） Plateau， while the Middle East jet is stronger； the positive （negative） phase of North Atlantic Oscillation （NAO） is conducive to more （less） snowfall over Tibetan Plateau， via modulating the SEA teleconnection and key circulation systems such as the Middle East jet stream.