2024年长江中下游梅雨集中期大气环流特征分析  

Analysis of atmospheric circulation characteristics during Meiyu concentrated period in 2024 in middle and lower reaches of Changjiang River

作　　者：邱辉 马艺铭 祁海霞[1] QIU Hui;MA Yiming;QI Haixia(China Meteorological Administration Basin Heavy Rainfall Key Laboratory/Hubei Key Laboratory for Heavy Rain Monitoring and Warning Research,Institute of Heavy Rain,China Meteorological Administration,Wuhan 430205,China;Bureau of Hydrology,Changjiang Water Resources Commission,Wuhan 430010,China)

机构地区：[1]中国气象局武汉暴雨研究所中国气象局流域强降水重点开放实验室/暴雨监测预警湖北省重点实验室,湖北武汉430205 [2]长江水利委员会水文局,湖北武汉430010

出　　处：《人民长江》2024年第12期30-38,共9页Yangtze River

基　　金：中国气象局流域强降水重点开放实验室项目(2023BHR-Y10);国家重点研发计划项目“空天地一体化流域性大洪水实时精准监测和精确预报技术与装备”(2022YFC3002701)。

摘　　要：为提高梅雨期强降雨过程的预报水平,利用长江流域逐日雨量站资料和NCEP再分析资料,对2024年长江中下游梅雨集中期异常特征及其大尺度环流成因进行了分析,并与2016年梅雨集中期特征进行了对比。结果表明:①2024年长江中下游梅雨有明显的阶段性特征,6月17日至7月2日为梅雨集中期,期间发生4次强降雨过程,主雨区均位于长江中下游干流附近及两湖水系中北部;7月2日后主雨区北抬至长江干流北部,梅雨集中期结束,长江流域降雨形态由南多北少转为北多南少。②梅雨集中期间,高、中、低层环流系统的耦合是长江中下游强降雨形成和维持的大尺度环流背景。4次降雨过程,中高纬度均呈现“两槽一脊”经向型环流配置,西太平洋副高主体呈稳定的带状分布,来自孟加拉湾和西太平洋的水汽输送强盛,通过强烈的西南风将暖湿气流向长江中下游地区输送,冷暖空气长时间在长江中下游干流南北两侧交汇,导致梅雨集中期降雨过程不断,降雨异常偏多。③2024年和2016年梅雨集中期有诸多共同特点,如梅雨特征相似、强度基本相当,均出现在厄尔尼诺事件的衰减阶段,副高偏强、偏西,西南暖湿气流偏强。研究成果可为长江流域梅雨期防洪减灾工作提供参考。To enhance the forecast level of heavy rainfall during the Meiyu period,causes of abnormal characteristics and large-scale circulation during the Meiyu concentrated period in 2024 in the middle and lower reaches of the Changjiang River were analyzed by using the daily precipitation station data and NCEP reanalysis data.Additionally,a comparison was made with the characteristics of the Meiyu concentrated period in 2016.The results showed that:①The Meiyu period in the middle and lower reaches of the Changjiang River in 2024 had obvious phased characteristics.The period from June 17th to July 2nd was a Meiyu concentrated period,during which four heavy rainfall events occurred.The main rainfall areas were along the mainstream of the middle and lower reaches of the Changjiang River,as well as in the central-northern parts of the Dongting Lake and Poyang Lake watersheds.After July 2nd,the main rainfall area moved northward to the northern part of the Changjiang River mainstream,so the Meiyu concentrated period ended.The rainfall pattern in the Changjiang River Basin has changed from more in the south and less in the north to more in the north and less in the south.②The coupling of high,middle,and low-level circulation systems was the large-scale circulation background for the formation and maintenance of heavy rainfall in the middle and lower reaches of the Changjiang River during the Meiyu period.During the four rainfall events,a meridional circulation pattern"two troughs and one ridge"was observed at mid-to-high latitudes,while the Western Pacific Subtropical High(WPSH)maintained a stable zonal distribution.Strong water vapor from the Bay of Bengal and the western Pacific Ocean was transported to the middle and lower reaches of the Changjiang River by prevailing southwest winds.Cold and warm air converged persistently on both sides of the mainstream of the middle and lower reaches of the Changjiang River.All these factors lead to relentless rainfall and abnormally high precipitation totals during the Meiyu concen

关 键 词：强降雨 梅雨集中期 大气环流 长江中下游 2024年长江洪水 

分 类 号：P458[天文地球—大气科学及气象学]