中文摘要：

气候跃迁以后ENSO事件明显分为两类，这两类事件对全球气候会产生相当不同的影响。早期的研究主要从定性角度来划分两类事件，而近年来的研究则开始通过经验正交分解和奇异值分解等方法得到能够描述两类事件的模态，进而定义能够区分两类事件的指数组，从定量角度对两类事件进行划分。本文总结了近年来对两类事件进行分类的方法，并比较了不同指数组对两类ENSO事件的区分能力。

英文摘要：

After the climate shift, ENSO events could be classified into two different types. These two types of ENSO events exert quite different influence on the global climate. Earlier studies mostly classified ENSO events qualitative- ly, while the recent studies started to classify ENSO events quantitatively through mathematical methods like Empirical Orthogonal Function and Singular Value Decomposition. They obtained EOF modes that could describe different types of ENSO events and then defined indices that could classify ENSO events. The progress of the investigation on the classification of two types of ENSO events is summarized, and also a comparison of classification abilities among dif- ferent index groups is made.