1961~2017年华南区域性持续高温过程年际变化成因分析  

Analysis of Interannual Variation of Regionally Persistent High-Temperature Events in South China during 1961–2017

作　　者：董少柔 林爱兰[2] 董彦彤 DONG Shaorou;LIN Ailan;DONG Yantong(Guangdong Climate Center,Guangzhou 510080;Institute of Tropical and Marine Meteorology/Guangdong Provincial Key Laboratory of Regional Numerical Weather Prediction,China Meteorological Administration,Guangzhou 510640;College of Ocean and Meteorology,Guangdong Ocean University,Zhanjiang 524088)

机构地区：[1]广东省气候中心,广州510080 [2]中国气象局广州热带海洋气象研究所/广东省区域数值天气预报重点实验室,广州510640 [3]广东海洋大学海洋与气象学院,湛江524088

出　　处：《大气科学》2023年第5期1325-1340,共16页Chinese Journal of Atmospheric Sciences

基　　金：国家重点基础研究发展计划项目2018YFC1505801;国家自然科学基金项目41575043;广东省气象局科学技术研究青年基金项目GRMC2020Q04。

摘　　要：本文利用近60年我国气象站的日最高气温、降水资料以及NCEP/NCAR大气多要素等全球格点资料,基于华南区域性持续高温历史过程定义夏季区域性持续高温指数(RPH),分析影响华南夏季区域性持续高温年际异常的大气环流及下垫面海温因子。主要结果表明,在华南夏季持续高温偏重年,华南区域对流层高、中、低层均受反气旋性环流异常控制,在华南上空垂直方向上表现出深厚的大气动力和热力异常,华南夏季持续性高温的年际异常也与欧亚东传波列和热带大范围环流异常密切联系。热带印度洋、热带太平洋以及北大西洋三大洋海温异常共同影响华南区域性持续高温的年际异常,其中热带印度洋、太平洋海温异常主要有利于南海—西太平洋反气旋性环流异常的形成,使副热带高压偏西偏强,北大西洋海温异常则有利于高层欧亚波列的加强,使南亚高压在东亚地区加强东伸。在各区域海温异常共同作用下,华南在对流层高、低层反气旋性环流的控制下,大气产生强烈的下沉运动,一方面大气绝热增温,另一方面使大气晴空少云、地面接收更多的太阳辐射,从而有利于高温偏重。This study investigates the general circulation and external forcing factors that synergistically affect interannual variation in regional persistent high-temperature events(RPHs)in South China during summer.Several observational data obtained from meteorological stations over the last 60 years and the NCEP/NCAR Reanalysis data set are used.The RPH index is defined based on historical regionally persistent high-temperature events in South China.Under the control of anticyclones throughout the troposphere,deep atmospheric dynamics and thermal anomalies occurred in vertical regions over South China during the years when a large number of RPHs occurred.The interannual variation in RPHs in South China is closely associated with the eastward-propagating wave trains over Eurasia and the large circulation anomaly in the tropics owing to the combined effect of sea surface temperature anomalies(SSTA)from the tropical Indian Ocean,tropical Pacific Ocean,and North Atlantic Ocean.The generation of anticyclone anomaly over the South China Sea in the western Pacific Ocean,which led to the westward extension of strengthened western Pacific subtropical high,results from the SSTA from the tropical Indian Ocean and the tropical Pacific Ocean.The enhancement of wave trains over Eurasia in the upper troposphere,which led to the eastward extension of strengthened South Asia high,results from the SSTA of the North Atlantic Ocean.Thus,strong downdraft is generated under the control of anticyclones throughout the troposphere over South China with a combined effect of these key regions of oceans.The large number of RPHs stems from this strong downdraft,which brings adiabatic heating and strengthened solar radiation heating at the surface.

关 键 词：区域性持续高温过程 华南 大气环流 海表面温度 

分 类 号：P466[天文地球—大气科学及气象学]