El Niño

View of the Earth from space

What is El Niño?

El Niño Southern Oscillation (ENSO) is a naturally occurring, periodical climate change caused by variations in sea surface temperatures over the tropical eastern Pacific Ocean. The Southern Oscillation is a see-saw shift in surface air pressure between the eastern and western halves of the Pacific. When pressure rises in the east, it falls in the west and vice versa. El Niño is characterized by unusually warm temperatures and La Niña by unusually cool temperatures. The ENSO cycle, both El Niño and La Niña, causes global changes of both temperatures and rainfall.

Learn more about El Niño

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