Before E1 Nino events onset, the subsurface water in western equatorial Pacific Ocean continues to be warmer, and strength of westerly anomaly are enhanced and its frequency increases.

• 在厄尔尼诺发生前；赤道西太平洋次表层海水出现持续性增暖；赤道西太平洋西风异常频率加快；强度增强.