夏季低空越赤道气流与ENSO的关系

Relationship between Summer Cross-Equatorial Flows and ENSO

利用NCEP/NCAR风场和海温等资料,分析了东半球夏季低空各支越赤道气流与ENSO循环的关系及其年代际变化,结果表明:东半球夏季低空越赤道气流强度的年际变化和ENSO循环密切相关,ElNino年夏季马斯克林高压减弱,导致索马里越赤道气流变弱,而澳大利亚高压加强, 105°E及其以东的越赤道气流明显加强,LaNina年则相反;夏季越赤道气流与ENSO的年际关系具有年代际变化特征,索马里越赤道气流与ENSO的关系在 20世纪 70年代末变弱,而 105°E及其以东的越赤道气流与ENSO的关系在 20世纪 60年代末增强。

The interannual relationships and its interdecadal variabilities between the intensity of summer 850hPa cross-equatorial flows in the Eastern Hemisphere and ENSO are analyzed by using NCEP/NCAR reanalysis data and the sea surface temperatures data of Hadley Center.Results show that Mascarene High was weaker(stronger) and Australia High stronger(weaker) than normal in the El Nino(La Nina) years,which caused summer 850hPa Somali jet was weaker(stronger) and the cross-equatorial flows of about 90°E,105°E,125°E and 150°E were stronger(weaker) than normal.The interannual relationship between Somali jet and ENSO was weakened in the late 1970s while the interannual relationships between the cross-equatorial flows of about 105°E,125°E and 150°E and ENSO were enhanced in the late 1960s.