夏季105～125°E垂直经圈环流变化特征及其与海温的联系  

Characteristics of summer meridional circulation changes over 105—125°E and their relations with SST

作　　者：岳阳[1,2] 管兆勇[2] 谌伟[3] 

机构地区：[1]湖北省气象局,湖北武汉430074 [2]南京信息工程大学气象灾害省部共建教育部重点实验室,江苏南京210044 [3]武汉中心气象台,湖北武汉430074

出　　处：《大气科学学报》2011年第4期400-409,共10页Transactions of Atmospheric Sciences

基　　金：国家重点基础研究发展计划项目(2011CB403406);国家自然科学基金资助项目(40475028)

摘　　要：采用NCEP/NCAR再分析资料,利用质量流函数方案和EOF(empirical orthogonal function,经验正交函数)分解,研究了1979—2006年夏季105～125°E范围垂直经圈环流的变化特征及其与邻近海域海温变化的联系。结果表明:1)在105～125°E区域,夏季北半球Hadley环流明显偏强,和南半球Hadley环流对称出现,形成明显的"Hadley环流对"。2)小波分析显示,Hadley环流变化有准2～4a和4～6a周期。近28a来,南半球Hadley环流有南退趋势,北半球Hadley环流逐渐增强,尤其是20世纪90年代中期之前,这种变化较显著。3)105～125°E区域夏季"Hadley环流对"的异常和邻近海域海表温度关系密切。无论是IOD(Indian Ocean Dipole)事件还是ENSO均对东亚经圈剖面内"Hadley环流对"产生影响,Hadley环流的主要模态EOF1与同期和滞后的SSTA的相关在太平洋上表现出El Nino发展期、盛期的海温分布形态。南半球Hadley环流偏北(南),北半球Hadley环流减弱(增强),则到来的冬季的El Nino(La Nina)发展,这对ENSO事件具有一定的预报意义。IOD事件对南半球Hadley环流的影响是显著的,当负IOD事件时,南半球Hadley环流减弱,但正IOD事件时并未显著相反。Based on the mass stream function scheme and EOF（empirical orthogonal function）,the NCEP/NCAR reanalysis data were used to investigate the meridional circulation changes and their relations with SSTA（sea surface temperature anomaly） form 1979 to 2006.The conclusions are as follows：（1）The south Hadley cell emerges together with the boreal Hadley cell which is more intensive over 105—125°E in boreal summer.These two meridional circulations are named as the ＂Hadley cell pair＂;（2）During the past 28 years,this pair of Hadley cells varies with periodicities of 2—4 and 4—6 years.The south Hadley cell tends to move southward while the intensity of boreal Hadley cell tends to stronger,especially before the mid 1990s;（3）Variations of Hadley cell pair is significantly correlated with IOD（Indian Ocean Dipole） and ENSO events.Lag and simultaneous correlations of the leading EOF mode for Hadley cells with SSTA is consistent with the SST pattern of El Nino developing or prevailing period over the Pacific.That the south Hadley cell is northward（southward） and that the boreal Hadley cell is weak（severe） are correlated with the development of El Nino（La Nina） in the coming winter.This can be a potential indicator in predicting ENSO events.The IOD SSTA is able to change the south Hadley cell.With negative IOD events,the south Hadley cell is weakened.However,with positive IOD events,there is no obvious opposite phenomenon.

关 键 词：Hadley环流对 EOF 海面温度 ENSO 

分 类 号：P434[天文地球—大气科学及气象学]