ENSO影响热带大气季节内振荡的年代际变化特征

Interdecadal variation feature of impacts on tropical atmospheric interseasonal oscillation by ENSO

为了研究厄尔尼诺和南方涛动(ENSO)现象影响热带大气季节内振荡(ISO)的年代际变化特征,利用奇异值分解(SVD)、小波分析和经验正交函数分析(EOF)等方法对热带大气ISO强度指数、赤道中东太平洋海温及热带大气环流场进行了分析。计算结果显示,20世纪70年代中期以前,ENSO对热带大气ISO的影响较弱;70年代中期以后,ENSO对热带大气ISO的影响加强。造成上述年代际变化的原因与热带大气环流的年代际变化有关,因此,ENSO对热带大气ISO的影响也存在年代际变化。

To study the interdecadal variation feature of the tropical atmospheric interseasonal oscillation impacted by El Ni珘no and South oscillation（ENSO）phenomenon,singular value decomposition（SVD）,wavelet analysis and orthogonal function analysis（EOF）method were used to analyze interseasonal oscillation（ISO）intensity index,eastern and central equator Pacific sea surface temperature（SST）and tropical atmospheric circulation field.Results show that before the last mid-1970 sENSO impacts on the tropical atmospheric interseasonal oscillation is weak,but the impacts intensifies after that.The cause is that there is interdecadal variation in tropical atmospheric circulation field.There is also interdecadal variation in impacts ENSO on ISO.