2An El Niño is a temporary change in the climate of the Pacific ocean near the equator. The ocean surface water warms up.At the same time, the place where big thunderstorms usually occur on the equator, moves eastward toward the United States.
5Usually, the wind blows strongly from east to west along the equator Usually, the wind blows strongly from east to west along the equator. This pushes warm surface water toward Asia, and cold, deep water gets pulled up from below near the U.S. So normally there is warm water near Asia, cold water near the Americas.WestEast
7In an El Niño, the winds pushing the water around get weaker, and the warm water near Asia moves back toward the Americas.The cold water sinks, and the warm water floats making the surface water warmer.
8Normal Ocean Conditions North AmericaSouthAmericaAsiaAustraliaPacificOceanWarmNormal Ocean Conditions
13Almost five hundred years ago, fishermen in South America noticed that every few years, the water became warm around Christmas time. This warmer-than-usual water was not very good for fishing. They named this pattern "El Niño," for the Christ Child, whose birth they celebrated on Christmas day.