Tibetan Plateau snow cover (TPSC) has subseasonal variations and rapidly influences the atmosphere. In this study, we present the rapid response of the East Asian trough (EAT) within a week to subseasonal variations in TPSC during the boreal winter. Using snow cover analysis obtained from the daily interactive multisensor snow and ice mapping system and the ERA‐Interim reanalysis, a considerable relationship between TPSC and 500‐hPa geopotential height anomalies over the downstream EAT region is found. Significant negative (positive) 500‐hPa geopotential height anomalies originating from the Tibetan Plateau and moving into the EAT region appear within a week following anomalous positive (negative) TPSC events, which lead to changes in EAT strength. Thus, a significantly enhanced (reduced) intensity of the EAT occurs approximately 5–6 days after increased (decreased) TPSC. Numerical experiments confirm the causality of this relationship. Further analysis of the quasi‐geostrophic geopotential height tendency equations in numerical experiments indicates that such EAT variations result from anomalous thermal advection from the Tibetan Plateau forced by TPSC.

中文翻译：

---

东亚海槽对青藏高原积雪的快速响应

青藏高原的积雪（TPSC）具有季节性变化，并迅速影响大气。在这项研究中，我们介绍了北亚低谷（EAT）在寒冬期间对TPSC的亚季节变化的快速响应。利用从日常互动式多传感器冰雪制图系统获得的积雪分析和ERA-Interim重新分析，发现下游EAT地区TPSC与500-hPa地势高度异常之间存在相当大的关系。在TPSC异常正（负）事件发生后的一周内，出现了源自青藏高原并进入EAT地区的显着的负（正）500-hPa高度势异常，这导致EAT强度发生了变化。从而，TPSC增加（减少）后约5–6天，EAT的强度显着增强（降低）。数值实验证实了这种关系的因果关系。在数值实验中对准地转位势高度趋势方程的进一步分析表明，这种EAT变化是由TPSC强迫青藏高原热对流异常引起的。