Getting a Longer Heads-Up on El Niño

Changes in Atlantic Ocean sea surface temperatures can be used to predict extreme climatic variations known as El Niño and La Niña more than a year in advance, according to research conducted at Korea’s Pohang University of Science and Technology and published in the journal Scientific Reports.

The El Niño Southern Oscillation (ENSO) is an irregular, periodic variation in trade winds and sea and air temperatures in the equatorial region of the Pacific Ocean, . Its warming phase of sea surface temperatures, called El Niño, and cooling phase, called La Niña, affects weather and climate around the world. For example, El Niño conditions typically generate more typhoons in the Pacific Ocean and fewer hurricanes in the Atlantic Ocean, while La Niña conditions usually reverse the trend.

Extensive studies have been conducted to better understand what triggers a distinct oscillation in order to predict associated climatic events. But accurate predictions are still limited to about a year or less before an ENSO swing. For example, studies have found that a peak in warm water in the equatorial Pacific precedes El Niño by about eight months. Also, an abnormal drop in sea surface temperatures in the tropical North Atlantic in early spring precedes El Niño conditions in the Pacific within about nine months.

Now, researchers at Pohang University of Science and Technology and colleagues in Hawaii and Japan have found that an abnormal rise in sea surface temperatures in a large body of warm water, called the Atlantic Warm Pool—comprising the Gulf of Mexico, the Caribbean Sea, and the western tropical North Atlantic—triggers La Niña about 17 months later.

Read more at Pohang University of Science & Technology (POSTECH)

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