El Niño and the World's Weather

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Periodically we find unusually warm ocean currents in the Pacific Ocean. Moving along the equator, they bring warm water to the west coast of South America. The Spanish name for these currents is El Niño, which means Little Boy.

The warming of the water in the tropical Pacific Ocean is the first sign of El Niño. It often triggers major changes in global weather patterns. These far reaching consequences were seen in the droughts and wild fires in Australia in 1982, in a rare hurricane in Hawaii, and flooding in Louisiana. In 1992, El Niño caused more rain in a two week period in southern California than they usually receive in a year.

Accurately predicting the next occurrence of El Niño is difficult because the reasons for its appearance are not well understood. Historical records show that El Niño has probably been occurring for centuries. It happens unpredictably every two to seven years.

Ocean warming causes more warm air to rise. This changes the air pressure and flow patterns in the high altitude winds, which are responsible for directing the movement of weather. The severity of the El Niño effect depends on how much the ocean actually warms.

So next time there’s a report of an unusually warm Pacific Ocean, it may affect you even if you live in another part of the world.