利用风场、20℃等温线深度、海表温度以及Wheeler·和Hendon提出的逐日MJO指数资料,通过合成分析方法对比分析了EP型和CP型El Nio发生前各要素场的特征,以及近30年来两类El Nio事件发生前MJO活动的差异。结果表明,在赤道西太平洋,EP型El Nio的异常西风要早于CP型El Nio出现,其强度也远远强于CP型事件。EP型El Nio的异常西风在发生前2个月已东扩至东太平洋地区,而CP型El Nio的异常西风在El Nio事件发生前3个月东扩至日界线附近,此后也只维持在日界线以西。而在赤道东太平洋,不同于EP型El Nio,CP型El Nio事件在El Nio事件发生前始终有偏东风存在。EP型El Nio温跃层有明显的加深东移现象,温跃层的演变要超前于海表温度的变化。由MJO处于5~8位相的异常概率分布,可知EP型El Nio在中西太平洋的MJO活动要比CP型El Nio早发生,比较赤道纬向风平方的均方差,发现EP型El Nio发生前对应的MJO活动要明显地强于CP型El Nio事件。 Using the wind field, 20 ℃ isotherm depth, sea surface temperature and the daily MJO index data proposed by Wheeler · and Hendon, the characteristics of each element field before and after the occurrence of EP and CP El Nio were analyzed by the method of synthetic analysis The differences of MJO activities before the occurrence of two types of El Nio events in recent 30 years. The results show that in the western equatorial Pacific, the anomalous westerly of EP-type El Nio occurs earlier than that of CP-type El Nio, and its intensity is much stronger than that of CP-type. In the EP El Nio anomaly westerlies expanded eastward to the eastern Pacific two months before the occurrence, while the anomalous westerly in the CP El Nio eastward extended to near the daily limit three months before the El Nio incident Since then, it has only remained west of the date line. In the eastern equatorial Pacific, unlike the El-Ni EP model EP, the El Nio CP event always has a northerly easterly wind before the El Nio event. The El Nio EP thermocline obviously deepens the eastward migration, and the thermocline evolution advances ahead of the sea surface temperature. From the anomalous probability distribution of MJO in the 5th to 8th phases, it can be seen that the MJO activity of EP-type El Nio occurs earlier than that of CP-type El Nio in the western and central Pacific. The mean square error of the equatorial zonal wind is compared. The corresponding MJO activity before Nio was significantly stronger than that of CP El Nio event.