2024年广西前汛期降水极端性气候背景分析  

Analysis of the climatic background of precipitation extremes during the pre-rainy season in Guangxi in 2024

作　　者：朱秋宇 覃卫坚[1] 蔡悦幸 李妍君 ZHU Qiuyu;QIN Weijian;CAI Yuexing;LI Yanjun(Guangxi Climate Centre,Nanning 530022,China)

机构地区：[1]广西壮族自治区气候中心,南宁530022

出　　处：《气象研究与应用》2024年第4期45-49,共5页Journal of Meteorological Research and Application

基　　金：广西气象科研计划项目(桂气科2023Z005、桂气科2024QN04);广西自然基金项目(2024GXNSFBA010025);广西极端暴雨形成机理及预报技术研究创新团队项目。

摘　　要：2024年前汛期(4—6月)广西降雨量和暴雨日数均为历史同期最多,风雹灾害近30 a最强,部分地区出现极端天气事件。利用1951年1月至2024年10月广西90个地面气象观测站逐日降水资料和NCEP/NCAR再分析资料及美国国家海洋和大气管理局(NOAA)扩展重建海表温度资料,利用气候异常度指数方法,分析2024年前汛期降水极端性环流和海温背景。结果表明,贝加尔湖至喀什湖区域的高度场异常偏高,有利于冷空气南下影响广西,导致降水量增多;赤道太平洋中部、赤道印度洋及南海西部的海温异常升高,促进对流活动增强,有利于向广西输送水汽,是2024年前汛期出现极端性降水的气候背景。The amount of rainfall and the number of days of heavy rainfall during the pre-rainy season of 2024(April-June)in Guangxi are the highest during the same period in history,and the wind and hailstorms are the strongest in the past 30 years,with extreme weather events occurring in some areas.Based on the daily precipitation data from 90 ground-based meteorological observation stations in Guangxi from January 1951 to October 2024 and the NCEP/NCAR reanalysis data and the SST data from the National Oceanic and Atmospheric Administration(NOAA),this paper analyses the precipitation extremes,circulation patterns and SST background during the first flood season of 2024 by using the climate abnormality index method.The results indicate that the anomalously high geopotential height field in the region from Lake Baikal to Lake Balkhash is favourable to the southward influence of cold air on Guangxi,leading to an increase in precipitation;the anomalously high SSTs in the central equatorial Pacific Ocean,the equatorial Indian Ocean and the western part of the South China Sea promote the enhancement of convective activities,which is favourable to the transport of water vapour to Guangxi,and constitutes a climatic background for the occurrence of extreme precipitation in the pre-rainy season of 2024.

关 键 词：前汛期 降水极端性 气候背景 气候异常度 

分 类 号：P426.6[天文地球—大气科学及气象学]