中国南方春季土壤湿度对夏季干热少雨复合事件的影响  

Effects of spring soil moisture on compound events of high temperature,low humidity,and rainfall in South China

作　　者：陈玥 王爱慧[2] CHEN Yue;WANG Aihui(College of Atmospheric Sciences,Lanzhou University,Lanzhou 730000,China;Nansen-Zhu International Research Centre,Institute of Atmospheric Physics,Chinese Academy of Sciences,Beijing 100029,China)

机构地区：[1]兰州大学大气科学学院,甘肃兰州730000 [2]中国科学院大气物理研究所竺可桢-南森国际研究中心,北京100029

出　　处：《大气科学学报》2023年第3期332-344,共13页Transactions of Atmospheric Sciences

基　　金：国家杰出青年科学基金资助项目(41925021);国家重点研发计划项目(2022YFC3002803)。

摘　　要：针对中国南方极端气候事件成因,本研究综合考虑高温、少雨和干燥三种极端事件,将其异常同时超出1959—2022年间1倍年际标准差定义为干热少雨复合事件,通过合成分析和相似环流-动力调整方法,研究了春季土壤湿度对夏季干热少雨复合事件的影响及物理机制,进一步对2022年夏季南方极端干热少雨复合事件开展深入分析。结果表明:1)中国南方地区春季土壤湿度与夏季气候局地耦合的热点与2022年夏季气温、降水和相对湿度的变率高值区基本吻合;2)春季长江流域及黄淮地区土壤偏干,且东南地区偏湿时,夏季出现干热少雨复合极端事件概率加大;3)春季土壤湿度通过调节局地蒸散和净辐射能量的分配影响夏季气候变率。本研究对改善干热少雨复合事件的预测具有重要参考价值。The summer of 2022 exhibits significant characteristics of high temperature,low humidity,and rainfall in South China.Previous studies have focused on extreme events of high temperature and low rainfall in summer,whereas attention to near-ground relative humidity,which is closely related to human comfort and crop growth,has been relatively insufficient.In this study,we define events of positive temperature anomaly,negative precipitation anomaly,and negative relative humidity anomaly exceeding one time of the interannual standard deviation between 1959 and 2022 are as compound events of summer high temperature,low humidity,and rainfall.Monthly ERA5 atmospheric reanalysis data of 1959—2022 are used in this study.We study the effect of spring soil moisture on the compound events in summer by composite analysis and a dynamic adjustment approach based on constructed circulation analogs,and the physical mechanism is analyzed.The results show that:1)The hot spots of the coupling between spring soil moisture and summer climate in south China are basically consistent with the high variability of summer temperature,precipitation,and relative humidity in 2022.2)When the soil in the Yangtze River Basin and Huang-Huai area is dry in spring and the southeast area is wet,the compound events of drying and heat will occur in summer.3)The effect of spring soil moisture on summer climate variability is mainly realized by adjusting the distribution of local evapotranspiration and net radiation energy.The study of the compound extreme events of high temperature,low humidity,and rainfall is of great significance in effectively preventing all kinds of disasters and safety accidents caused by them,protecting people s lives and property,and maintaining social production order.

关 键 词：中国南方地区 复合极端事件 土壤湿度 

分 类 号：P46[天文地球—大气科学及气象学]