Contribution of Water Vapor to the Record-Breaking Extreme Meiyu Rainfall along the Yangtze River Valley in 2020

作     者：Licheng WANG Xuguang SUN Xiuqun YANG Lingfeng TAO Zhiqi ZHANG Licheng WANG;Xuguang SUN;Xiuqun YANG;Lingfeng TAO;Zhiqi ZHANG

作者机构：CMA-NJU Joint Laboratory for Climate Prediction StudiesSchool of Atmospheric SciencesNanjing UniversityNanjing 210023 

出 版 物：《Journal of Meteorological Research》 (气象学报（英文版）)

年 卷 期：2021年第35卷第4期

页      面：557-570页

核心收录：

学科分类：07[理学] 070601[理学-气象学] 0706[理学-大气科学] 0816[工学-测绘科学与技术] 0825[工学-航空宇航科学与技术] 

基　　金：Supported by the National Key Research and Development Program of China(2018YFC1505803) National Natural Science Foundation of China(41775074) Foundation for Innovative Research Groups of the National Natural Science Foundation of China(41621005) 

主　　题：water vapor convective activity Meiyu rainfall Indian Ocean Atlantic Ocean 

摘      要：A record-breaking extreme Meiyu rainfall occurred along the Yangtze River valley(YRV)in 2020 since 1961,persisting from 11 June to 31 July with the largest amount and the highest *** the aspect of water vapor,the causes of its formation are revealed in this *** 2020 Meiyu rainfall amount is directly attributed to the greatly enhanced vertically integrated water vapor transport(IVT)convergence,which is in turn primarily determined by the mean circulation dynamic(MCD)contribution associated with anomalous East Asian summer monsoon(EASM)and the thermodynamic component(TH)contribution due to water vapor *** MCD contribution is mainly responsible for the extreme Meiyu rainfall amount and abundant water vapor convergence in the YRV,whereas the TH contribution tends to shift Meiyu rain belt northward to the Yangtze-Huaihe River valley,extending the Meiyu rainfall coverage ***,the excessive moist static energy(MSE)associated with the largest water vapor anomaly could substantially increase the atmospheric instability,favoring the extreme 2020 Meiyu rainfall *** terms of the tremendous IVT to the YRV from both the South China Sea and Bay of Bengal during the 2020 Meiyu period,the low-level anticyclone anomalies over the western North Pacific(WNP)and Bay of Bengal provide appropriate atmospheric circulation conditions,and they are generated by the super suppressed WNP convective activities as a Matsuno-Gill type response,which are further attributed to the combined warm SST anomalies in both the tropical western Indian Ocean(TWIO)and tropical Atlantic Ocean(TAO)eventually.