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El Niño : Description

What's an El Niño?
Every 3-7 years, the seawater at the surface of the equatorial Pacific off the west coast of South America becomes unusually warm. This is an El Niño event.

Although El Niño events involve changes in the ocean-atmosphere system across the Pacific and have consequences for weather around the world, equatorial Pacific changes are the most recognized.

For most people, the strongest images of El Niño include abnormally warm waters in the eastern equatorial Pacific, negative impacts on marine life, and other changes in climate. Although local climate impacts vary greatly, residents of the eastern Pacific in areas such as Peru and California tend to experience higher rainfall during El Niño. On the other side of the Pacific, people in Indonesia and Australia often experience drought.

The biological productivity of the eastern equatorial Pacific drops during El Niños. Fisheries along Peru have been known to collapse and the number of starving marine mammals increases.


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