两类ENSO背景下中国东部夏季降水的环流特征及关键系统  

Circulation characteristics and critical systems of summer precipitation in eastern China under the background of two types of ENSO events

作　　者：王黎娟[1] 蔡聪 张海燕[1,3] WANG Lijuan;CAI Cong;ZHANG Haiyan(Key Laboratory of Meteorological Disaster,Ministry of Education(KLME)/Joint International Research Laboratory of Climate and Environment Change(ILCEC)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD),Nanjing University of Information Science&Technology,Nanjing 210044,China;Dafeng Meteorological Bureau,Yancheng 224100,China;Wenzhou Environmental Monitoring Central Station,Wenzhou 325000,China)

机构地区：[1]南京信息工程大学气象灾害教育部重点实验室/气候与环境变化国际合作联合实验室/气象灾害预报预警与评估协同创新中心,江苏南京210044 [2]盐城市大丰区气象局,江苏盐城224100 [3]温州市环境监测中心站,浙江温州325000

出　　处：《大气科学学报》2020年第4期617-629,共13页Transactions of Atmospheric Sciences

基　　金：国家重点研发计划项目(2019YFC1510004);国家自然科学基金资助项目(41975085)。

摘　　要：利用全国160站逐月降水资料、74项环流指数、HadISST月平均海温资料以及NCEP/NCAR月平均再分析资料,对比分析了两类ENSO事件衰减阶段中国东部夏季降水及相应大气环流的差异,并探讨其可能成因。结果表明:1)EP型ElNio(LaNia)事件次年夏季,中国东部降水由北至南呈正负正(负正负)的三极型反相分布;CP型ElNio(LaNia)事件次年夏季,中国东部降水由北至南呈正负(负正)的偶极型反相分布;2)ElNio事件次年夏季,西北太平洋副热带高压(以下简称西太副高)及南亚高压均偏强,EP型西太副高偏西、南亚高压偏东,CP型西太副高范围更大、强度更强;LaNia事件次年夏季,西太副高及南亚高压强度偏弱,CP型强于EP型但弱于气候平均;3)ElNio事件期间西北太平洋上存在异常反气旋,EP型位置偏南,强度更强,持续时间更长,CP型位置偏北,范围更大;LaNia事件期间,西北太平洋区域至中国东南部存在异常气旋,EP型异常气旋的强度及范围均不及CP型;4)两类ElNio事件期间异常反气旋的差异可能与印度洋海盆增暖及太平洋海温持续性偏冷有关;两类LaNia事件期间异常气旋的差异可能由赤道西太平洋海温持续偏暖造成。Based on the monthly precipitation data of 160 meteorological observation stations in China,the 74 circulation indexes,HadISST monthly mean sea surface temperature data and NCEP/NCAR monthly mean reanalysis data,this paper compared and analyzed the differences of summer rainfall in eastern China and related atmospheric circulation in the decaying stage of two types of ENSO events,and discussed the possible mechanisms.The results are as follows:(1) In the following summer of EP type of ElNio (LaNia) events,precipitation in eastern China presents a three-pole-type of “+-+” (“-+-”) inverse distribution from north to south,while precipitation during the following summer of CP type of ElNio(LaNia) events in eastern China presents a dipole-type of “+-” (“+-”) inverse distribution from north to south.(2) The western Pacific subtropical high (WPSH) and the South Asia high (SAH) in the following summer of ElNio events are much stronger than the climatological normal.WPSH (SAH) of EP ElNio moves further westward (eastward).The area of WPSH of CP ElNio is larger than that of EP ElNio,and the intensity is stronger as well.During the following summer of LaNia events,WPSH and SAH of CP LaNia are stronger than those of EP LaNia but weaker than the climatological normal.(3) An anomalous anticyclone exists in the northwestern Pacific during ElNio events.The anticyclone of EP ElNio is southward and stronger,and lasts longer than that of CP ElNio,while the anticyclone of CP ElNio is northward and has larger range.However,during LaNia events,an anomalous cyclone exists in the northwestern Pacific region to southeastern China.The anomalous cyclone of CP LaNia is much stronger,with the area much larger than that of EP LaNia.(4) The difference of northwestern Pacific anomalous anticyclone between the two types of ElNio events may be related to the warming of the Indian Ocean Basin and the persistent abnormal cooling of SST in the Pacific Ocean.The difference of northwestern Pacific anomalous cyclone between two types of

关 键 词：两类ENSO 夏季降水 大气环流 异常反气旋 异常气旋 

分 类 号：P434[天文地球—大气科学及气象学]