The ocean, a huge system in itself, also interacts with the air currents that flow over the land. But the ocean reacts slowly to outside influences, making the ocean's trends more amenable to observation. Climatologists now attach critical importance to the study of El Nino, and see the ocean as being a key to climatological research.
聖嬰也抓狂與陸地輕巧流動的大氣相較，海洋是個龐大系統，對外界變動的刺激，反應緩慢，變化趨勢也較易掌握，因此抓住聖嬰「脈動」，已成氣候學的重要課題。