Importance of orographic gravity waves over the Tibetan Plateau on the spring rainfall in East Asia

作     者：Runqiu LI Xin XU Xiangde XU Theodore G.SHEPHERD Yuan WANG 

作者机构：Key Laboratory of Mesoscale Severe Weather/Ministry of Education and School of Atmospheric SciencesNanjing UniversityNanjing 210023China State Key Laboratory of Severe WeatherChinese Academy of Meteorological SciencesBeijing 100081China Department of MeteorologyUniversity of ReadingEarley GatePO Box 243Reading RG66BBUK 

出 版 物：《Science China Earth Sciences》 (中国科学（地球科学英文版）)

年 卷 期：2023年第66卷第11期

页      面：2594-2602页

核心收录：

学科分类：07[理学] 070601[理学-气象学] 0708[理学-地球物理学] 0706[理学-大气科学] 0704[理学-天文学] 

基　　金：supported by the Second Tibetan Plateau Scientific Expedition and Research Program(STEP)(Grants No.2019QZKK0105) the National Natural Science Foundation of China(Grants Nos.42122036,91837207,42230607) 

主　　题：Tibetan Plateau Orographic gravity waves Monsoon Spring persistent rainfall 

摘      要：The springtime persistent rainfall(SPR)is the major rainy period before the onset of summer monsoon in East Asia,which profoundly affects the regional and even global hydrological *** the great importance of the mechanical and thermal effects of the Tibetan Plateau(TP)large-scale orography on the formation of SPR,the impact of small-scale orography over the TP remains poorly *** we show that upward-propagating orographic gravity waves(OGWs),which occur as the subtropical westerlies interact with the TP s small-scale orography,contribute importantly to the *** breaking of OGWs induces a large zonal wave drag in the middle troposphere,which drives a meridional circulation across the *** rising branch of the meridional circulation acts to lower the pressure and increase the meridional pressure gradient to the south of the TP by dynamically pumping the lower-tropospheric air *** southwesterly monsoonal flow on the southeastern flank of the TP thus intensifies and transports more water vapor to East Asia,resulting in an enhancement of the *** finding helps more completely understand the impacts of TP s multiscale orography on the SPR and provides a new perspective on the westerly-monsoon synergy in East Asia.