副热带西风急流与中亚夏季降水的关系  

Relationship between the Subtropical Westerly Jet and Summer Rainfall over Central Asia from 1961 to 2016

作　　者：任国强 赵勇[1] REN Guoqiang;ZHAO Yong(Plateau Atmosphere&Environment Key Laboratory of Sichuan Province/School of Atmospheric Sciences,Chengdu University of Information Technology,Chengdu 610225,Sichuan,China)

机构地区：[1]高原大气与环境四川省重点实验室/成都信息工程大学大气科学学院,四川成都610225

出　　处：《高原气象》2022年第6期1425-1434,共10页Plateau Meteorology

基　　金：四川省科技计划项目(2020JDJQ0050);国家自然科学基金项目(41875102)。

摘　　要：基于美国国家环境预测中心(NCEP)/美国国家大气研究中心(NCAR)提供的大气环流再分析数据和全球降水气候中心(GPCC)提供的逐月降水数据,研究了副热带西风急流与中亚夏季降水的关系。结果表明,当副热带西风急流位置偏南时,中亚上空受异常气旋控制,印度半岛上空的异常反气旋将阿拉伯海的水汽向北输送,并通过中亚上空的异常气旋接力输送至中亚上空,导致中亚夏季降水偏多,反之亦然。青藏高原夏季风和热带印度洋海温是影响中亚副热带西风急流位置移动的重要因子。当热带印度洋海温整体暖异常时,南亚夏季风减弱,印度半岛降水减少潜热加热减弱,印度半岛西北侧对流层高层受异常气旋控制,导致中亚对流层中高层气温偏低;当青藏高原夏季风偏强时,高原降水增多潜热加热增强,高原西北侧对流层高层对应反气旋环流,导致中亚对流层高层气温偏低。二者共同导致中亚对流层中高层温度降低,形成异常气旋环流,导致中低纬西风加强,中高纬西风减弱,对应副热带西风急流南移,反之亦然。Based on the reanalysis data provided by the National Center for Environmental Prediction(NCEP)/National Center for Atmospheric Research(NCAR)and the monthly precipitation data provided by the Global Precipitation Climatology Center(GPCC)from 1961 to 2016,the relationships between the subtropical westerly jet and summer rainfall over central Asia were analyzed. The results show that when the subtropical westerly jet shifts south,the anomalous cyclone determines the central Asia,meantime the anomalous anticyclone over the Indian Peninsula and anomalous cyclone over central Asia transport the water vapor from the Arabian Sea into the central Asia,which cause more summer rainfall over central Asia,vice versa. The plateau monsoon over the TQinghai-Xizang Plateau and the surface sea temperature(SST)tropical Indian Ocean are well related to the jet position of subtropical westerly jet over central Asia. When positive anomalies of SST over whole tropical Indian Ocean,corresponding to weakened south Asian summer monsoon,it causes less rainfall and weakened latent heat over the Indian Peninsula. Based on the Gill atmospheric response,there is an anomalous cyclone over northwest flank of Indian Peninsula in upper troposphere,which causes the cooling of temperature in upper troposphere over central Asia;When the strengthened plateau monsoon over the Qinghai-Xizang Plateau,corresponding to more rainfall and strengthened latent heat,it causes an anomalous anticyclone over northwest flank of Qinghai-Xizang Plateau,which results in the cooling of temperature in upper troposphere over central Asia.Under the joint action of the plateau monsoon and SST over the Indian Ocean,the cooling of temperature in upper troposphere forms an anomalous cyclone in upper troposphere over central Asia,it causes more strengthened westerly at middle-low latitudes,corresponding to the jet shifting south,vice versa.

关 键 词：青藏高原季风 副热带西风急流 热带印度洋增暖 中亚干旱区 夏季降水 

分 类 号：P461.2[天文地球—大气科学及气象学]