Precipitation anomaly over the Tibetan Plateau affected by tropical sea-surface temperatures and mid-latitude atmospheric circulation in September  

作　　者：Ping ZHANG Anmin DUAN 

机构地区：[1]State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics(LASG),Institute of Atmospheric Physics,Chinese Academy of Sciences,Beijing 100029,China [2]College of Earth Science,University of Chinese Academy of Sciences,Beijing 100049,China [3]State Key Laboratory of Marine Environmental Science,College of Ocean and Earth Sciences,Xiamen University,Xiamen 361102,China

出　　处：《Science China Earth Sciences》2023年第3期619-632,共14页中国科学（地球科学英文版）

基　　金：supported by the National Natural Science Foundation of China(Grants Nos.41725018,91937302,&42030602)。

摘　　要：Tibetan Plateau(TP)precipitation is affected by anomalous circulation systems in both the tropics and mid-latitudes,due to the TP’s unique geographical location.By using observational,reanalysis,and CMIP6 model datasets,this study reveals the individual and joint effects of the Indian Ocean Dipole(IOD)and Silk Road pattern(SRP)on the interannual variability of TP precipitation in September.In the positive IOD phase,the zonal gradient of the sea-surface temperature anomalies(SSTAs)drives a Gill-type response with an anticyclonic anomaly over the Indian subcontinent and Bay of Bengal.To the north,anomalous westerlies induce a shallow trough,and the associated anomalous southwesterlies transport moisture to the southeastern TP,resulting in surplus precipitation there.Meanwhile,the westerly jet disturbances over the North Atlantic excite an SRP-like pattern,resulting in a baroclinic structure in northern India with the upper(lower)tropospheric anomalous anticyclone(cyclone)over west-central Asia(northern India).The anomalous southwesterlies to the east of the low-level cyclone transport abundant moisture to the southeastern TP,which results in increased precipitation there.The joint effects of IOD and SRP can explain nearly 52%of the TP precipitation anomaly,exceeding the contribution of IOD(19%)and SRP(27%)alone.Our results highlight the necessity of considering the joint effects of drivers in the tropics and mid-latitudes,providing a basis for more accurate simulations and predictions of TP precipitation.

关 键 词：Tibetan Plateau precipitation Interannual variability Indian Ocean Dipole Silk Road pattern 

分 类 号：P426.6[天文地球—大气科学及气象学]