印度洋dipole事件的年际变化与ENSO事件的联系

Correlation Between Interannual Indian Ocean Dipole and ENSO

通过对nino3指数和DMI序列的分析,发现两种物理现象都有4 a左右的主要周期,而且印度洋偶极子事件还存在有2 a左右的振荡周期,而厄尔尼诺事件在2 a时间尺度上周期性不明显;对nino3指数和DMI进行年际时间尺度滤波,结果表明,在年际时间尺度上,两者的相关性比未滤波时有了一定的提高;对年际滤波之后的偶极子事件和ELNINO事件的相关分析可以发现,ELNINO对于印度洋偶极子事件的影响要大于IOD对于太平洋ENSO事件,显示了两者物理现象的影响不对称。

Using the power spectra analysis of the nino3 and DMI time series, main period around 4 years of both cases are confirmed, moreover, the main period of 2 years is discovered on the Indian ocean dipole phenomenon. On the contrary, ELNINO show the 1 year around main period than IOD event. The correlation between interannual ELNINO and interannual IOD event has the higher value than that of ELNINO and IOD without filtering. The effect from ELNINO to IOD is stronger than the reversion.