Magnitude,Scale,and Dynamics of the 2020 Mei-yu Rains and Floods over China  

作　　者：Ambrogio VOLONTÉ Mark MUETZELFELDT Reinhard SCHIEMANN Andrew GTURNER Nicholas KLINGAMAN 

机构地区：[1]Department of Meteorology,University of Reading,Reading,RG66ES,UK [2]National Centre for Atmospheric Science,University of Reading,Reading,RG66ES,UK

出　　处：《Advances in Atmospheric Sciences》2021年第12期2082-2096,共15页大气科学进展（英文版）

基　　金：AV,MM,RS,AGT and NPK were supported by the COSMIC project through the Met Office Climate Science for Service Partnership(CSSP)China as part of the Newton Fund,contract number P106301.NPK was supported by a Natural Environmental Research Council(NERC)Independent Research Fellowship(NE/L010976/1)and by the ACREW programme of the National Centre for Atmospheric Science.We thank Omar V.MÜLLER for help with GloFAS-ERA5.

摘　　要：Large parts of East and South Asia were affected by heavy precipitation and flooding during early summer 2020.This study provides both a statistical and dynamical characterization of rains and floods affecting the Yangtze River Basin(YRB).By aggregating daily and monthly precipitation over river basins across Asia,it is shown that the YRB is one of the areas that was particularly affected.June and July 2020 rainfall was higher than in the previous 20 years,and the YRB experienced anomalously high rainfall across most of its sub-basins.YRB discharge also attained levels not seen since 1998/1999.An automated method detecting the daily position of the East Asian Summer Monsoon Front(EASMF)is applied to show that the anomalously high YRB precipitation was associated with a halted northward progression of the EASMF and prolonged mei-yu conditions over the YRB lasting more than one month.Two 5-day heavy-precipitation episodes(12−16 June and 4−8 July 2020)are selected from this period for dynamical characterization,including Lagrangian trajectory analysis.Particular attention is devoted to the dynamics of the airstreams converging at the EASMF.Both episodes display heavy precipitation and convergence of monsoonal and subtropical air masses.However,clear differences are identified in the upper-level flow pattern,substantially affecting the balance of airmass advection towards the EASMF.This study contextualizes heavy precipitation in Asia in summer 2020 and showcases several analysis tools developed by the authors for the study of such events.

关 键 词：East Asian summer monsoon 2020 China floods Yangtze River basin mei-yu front extreme precipitation 

分 类 号：P426.616[天文地球—大气科学及气象学] TV87[水利工程—水利水电工程]