伊朗高原和青藏高原夏季加热对塔里木盆地降水的影响  

Effects of the Summer Heating over the Iranian Plateau and the Qinghai-Xizang Plateau on Precipitation over the Tarim Basin

作　　者：陈佳毅 赵勇[1] CHEN Jiayi;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》2023年第4期858-869,共12页Plateau Meteorology

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

摘　　要：基于1971-2019年日本气象厅(Japan Meteorological Agency,JMA)提供的JRA-55地表感热、潜热通量、大气环流再分析资料和国家气象信息中心(National Meteorological Information Center,NMC)提供的逐月格点降水数据,分析了夏季伊朗高原和青藏高原热力异常与同期塔里木盆地降水的关系。结果表明:夏季伊朗高原主导加热方式为感热加热,青藏高原主导加热方式为潜热加热。奇异值分解分析发现,夏季两个高原地表热力异常均与塔里木盆地降水关系密切,考虑两个高原共同热力异常要比单一高原热力异常与塔里木盆地夏季降水的关系更紧密。当伊朗高原感热整体偏强,同时青藏高原潜热呈“北强南弱”的异常分布时,导致中亚对流层中高层气温偏低,对应中亚副热带西风急流位置南移,中亚和蒙古高原对流层中层受异常气旋和反气旋控制,塔里木盆地主要受异常偏南风影响,形成降水有利的环流条件;同时阿拉伯海水汽可以通过两步方式输送送至塔里木盆地上空,西北太平洋水汽受我国北方异常反气旋影响,也可向西输送进入塔里木盆地,为该区域降水提供有利的水汽条件。夏季伊朗高原和青藏高原均可单独加热影响塔里木盆地降水,但是对水汽输送的源地和路径存在一定差异,前者主要影响热带印度洋水汽的向北输送,后者可以同时影响热带印度洋水汽的向北输送和西北太平洋水汽的向西输送。Based on the JRA-55 surface sensible and latent heat flux,reanalysis circulation data provided by Japan Meteorological Agency(JMA),monthly grid precipitation data provided by the National Meteorological Information Center(NMC)during the period of 1971-2019.The effects of thermal anomalies over the Iran Plateau and the Qinghai-Xizang Plateau on summer precipitation over the Tarim Basin are analyzed.Results show that the sensible heat over the Iran Plateau and the latent heat over the Qinghai-Xizang Plateau play main roles in summer heating.The singular value decomposition(SVD)analysis has indicated that the surface thermal anomalies over the two plateaus are well related to summer precipitation over the Tarim Basin.Correlations suggest that thermal anomalies in the two plateaus have better relationships with summer precipitation over the Tarim Basin than one in single plateau.When the sensible heat strengthens over the Iran Plateau,and the latent heat strengthen in northern Qinghai-Xizang Plateau and weaken in southern Qinghai-Xizang Plateau,which can cause the middle to upper tropospheric cooling over central Asia.On the one hand,the subtropical westerly jet will shift south over central Asia,and there is an anomalous cyclone over central Asia and an anomalous anticyclone over Mongolian Plateau,which result in anomalous south wind prevailing over the Tarim Basin.On the other hand,the water vapor can be transport to the Tarim Basin by an anomalous anticyclone over the Arabian Sea and an anomalous cyclone over central Asia,meanwhile,the anomalous anticyclone over north China also can transport the water vapor from northwest Pacific to the Tarim Basin.Above both are contributed to more summer precipitation over the Tarim Basin.The single thermal anomalies over the Iran Plateau and the Qinghai-Xizang Plateau both can influence the summer precipitation over the Tarim Basin,but show partial difference related to the source and path of water vapor.The former only can affect water vapor transmission in the tropical India

关 键 词：伊朗和青藏高原 塔里木盆地 热力异常 共同影响 夏季降水 

分 类 号：P461.3[天文地球—大气科学及气象学]