Coupling of Land Surface Thermodynamics With Atmospheric Dynamics Effect on Summer Extreme Precipitation in the Northern Tibetan Plateau

Abstract In recent years, frequent extreme precipitation events have occurred in the northern Tibetan Plateau (NTP), increasing flood disaster risks in socio‐economic systems. Based on the Self‐Organizing Map method, this study analyzed the typical synoptic types causing extreme summer precipitation events in the NTP and the role of local and non‐local land surface thermal changes. Results show that there are two typical synoptic types that are conducive to the occurrence of extreme precipitation events in the NTP and with an increasing trend, namely the shortwave type and the zonal high‐pressure type. Coupling with these two synoptic types, the reduced soil moisture (SM) in the southwestern and northeastern TP has a prior promotion on extreme precipitation events corresponding to two typical synoptic types in the NTP. The reduction in non‐local SM in the southwestern TP results in a dipole circulation pattern, which leads to convergence of warm and cold air and promotes the transport of moisture from the southwestern TP to the NTP. The reduction in local SM in the northeastern TP contributes to the development of an anticyclone over the northern TP that drives monsoon moisture from the east of the TP, while simultaneously suppressing the eastward export of moisture from the westerlies, leading to increased precipitation in the NTP. This study demonstrates that both local and non‐local thermal effects of the TP can drive extreme precipitation when coupling with specific synoptic types, and it provides some assistance in disaster forecasting and prediction.