两类ENSO背景下中国东部夏季降水的环流特征及关键系统分析
投稿时间:2018-08-17  修订日期:2018-10-22  点此下载全文
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作者单位E-mail
王黎娟 南京信息工程大学 wljfw@163.com 
蔡聪 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  
张海燕 温州市环境监测中心站  
基金项目:国家自然科学基金项目(面上项目,重点项目,重大项目)
中文摘要: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,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El Ni?o(La Ni?a)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El Ni?o(La Ni?a)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)El Ni?o事件次年夏季,西北太平洋副热带高压及南亚高压均偏强,EP型西太副高偏强偏西、南亚高压偏强偏东,CP型副高范围更大,强度更强,南亚高压较气候平均偏强;La Ni?a事件次年夏季,副高及南亚高压强度偏弱,CP型强度强于EP型但弱于气候平均;3)El Ni?o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;La Ni?a事件期间,西北太平洋区域至中国东南部为异常气旋控制,且EP型异常气旋的强度及范围均不及CP型;4)两类El Ni?o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La Ni?a事件期间异常气旋的差异则可能由赤道西太平洋海温持续偏暖造成。 关键字:两类ENSO;夏季降水;大气环流;异常反气旋
中文关键词:两类ENSO  夏季降水  大气环流  异常反气旋
 
Circulation characteristics and critical systems analysis of summer precipitation in eastern China under the background of two types of ENSO events
Abstract:The anomalies of summer rainfall in China and related atmospheric circulations in decaying summer of two types of ENSO events were compared and analyzed, with the possible mechanisms discussed, using the monthly mean precipitation data of 160 meteorological observation stations and 74 circulation index in China, HadISST monthly mean Sea Surface Temperature reanalysis data, monthly mean reanalysis data from NCEP/NCAR. The results are as follows: 1)In the following summer of EP type of El Ni?o (La Ni?a) 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 El Ni?o(La Ni?a) events in eastern China presents a dipole-type of “+-”(“+-”) inverse distribution; 2)The Western Pacific Subtropical High(WPSH) and the South Asia High(SAH) in the following summer of El Ni?o events are much stronger than climatological normal. The WPSH(SAH) of EP El Ni?o moves further westward(eastward).The area of the WPSH of CP El Ni?o is larger than that of EP El Ni?o, and the intensity is stronger as well, the intensity of SAH is stronger than climatological normal;During the following summer of La Ni?a events, the intensity of WPSH and SAH of CP La Ni?a is stronger than that of EP La Ni?a but weaker than climatological normal. 3)An anomalous anticyclone excites in the northwestern Pacific during El Ni?o events, The intensity of anticyclone of EP El Ni?o is stronger, more to the south, and lasts longer than that of CP El Ni?o, while the area of anticyclone of CP type is larger and the position is more to the north. However, during La Ni?a events, the northwestern Pacific region to east-southern China is controlled by an anomalous cyclone. The intensity of anomalous cyclone of CP La Ni?a is much stronger, with the area much larger than that of EP La Ni?a; 4) Differences of western north pacific anomalous anticyclone between two types of El Ni?o events may be related to the heating of Indian Ocean basin and the persistent abnormal cooling of SST in Pacific Ocean; and differences of western north pacific anomalous cyclone between two types of La Ni?a events may be related to the persistent abnormal heating of SST in tropical western Pacific Ocean. Key words: two types of ENSO events; summer precipitation; atmospheric circulation; anomalous anticyclone
keywords:two types of ENSO events  summer precipitation  atmospheric circulation  anomalous anticyclone
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