|E l N i ñ o' s C o a s t s|
For hundreds of years, scientists have known where to look for the unusually warm water that signals the arrival of El Niño. The western coast of South America, particularly the coasts of Peru and Equador, are El Niño's favorite beaches. Every few years, warmer than usual water splashes onto the beaches, bringing with it the hot air that feeds rainstorms.
|This animation of El Niño (408k) illustrates the movement of the warm water after the trade winds weaken.|
When El Niño is not visiting, the warm surface water
along the coast of South America is normally blown away,
westward toward Asia, by the trade winds. It's a long way to
go, but the warm water arrives and gathers near Indonesia,
actually causing the Pacific Ocean to be deeper there.
Every few years, however, the trade winds stop blowing strongly,
allowing the excess warm water near Indonesia to drift back
toward South America, evening out the Ocean's depth.
Why do the trade winds stop blowing strongly? Scientists are not sure. The latest scientific instruments that are recording the 1997-1998 El Niño data may suggest some answers.
The extra warm water near South America creates extra warm air, causing extra rain. Meanwhile, on the Indonesian side, the decrease in warm water means a decrease in warm air, which means less rain. Serious drought conditions often result in that region of the world.
So scientists know where to look for the hot water, but we're still not entirely sure where to look for the effects of El Niño. Flooding in Peru and Ecuador is surely the result of El Niño. Drought in Indonesia is another result. But how about mild winters in Canada? Or excess rain in California? As scientists learn more about El Niño, it looks more as if El Niño's effects are everywhere.
The following resources offer excellent explorations of the global impact of El Niño.