Intense El Niño May Be Developing (Photo)

The 10-day average sea-surface height centered on May 2, 1997 (left), and May 3, 2014.
The 10-day average sea-surface height centered on May 2, 1997 (left), and May 3, 2014. (Shades of red and orange indicate warmer water that's above normal sea level; blue-green shows below-average sea level and temperatures; and white indicates normal sea-level conditions.) (Image credit: NASA Earth Observatory, TOPEX/Poseidon satellite (1997), Ocean Surface Topography Mission/Jason 2 satellite (2014).)

El Niño conditions seem to be developing in the equatorial Pacific Ocean, data from satellites and ocean sensors indicate.

A natural climate cycle that brings abnormally toasty temperatures to the Pacific Ocean, El Niño occurs when winds pile up warm water in the eastern part of the equatorial Pacific, triggering changes in atmospheric circulation that affects rainfall and storm patterns around the world. 

"What we are now seeing in the tropical Pacific Ocean looks similar to conditions in early 1997," said Eric Lindstrom, oceanography program manager at NASA headquarters, in an Earth Observatory statement. "If this continues, we could be looking at a major El Niño this fall. But there are no guarantees."

A network of sensors in the Pacific Ocean reveals a deep pool of warm water shifting eastward, supporting the satellite data, according to the Earth Observatory.

Model predictions issued on May 8 by the National Weather Service Climate Prediction Center forecast that the chances of an El Niño developing during the summer are more than 65 percent. "These atmospheric and oceanic conditions collectively indicate a continued evolution toward El Niño," the alert read.

This event may be just the beginning of more intense El Niños to come, according to research detailed Jan. 19 in the journal Nature Climate Change. That study suggested the most powerful El Niño events may occur every 10 years rather than every 20 years, due to rising sea-surface temperatures overall in the eastern Pacific Ocean.

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Managing editor, Scientific American

Jeanna Bryner is managing editor of Scientific American. Previously she was editor in chief of Live Science and, prior to that, an editor at Scholastic's Science World magazine. Bryner has an English degree from Salisbury University, a master's degree in biogeochemistry and environmental sciences from the University of Maryland and a graduate science journalism degree from New York University. She has worked as a biologist in Florida, where she monitored wetlands and did field surveys for endangered species, including the gorgeous Florida Scrub Jay. She also received an ocean sciences journalism fellowship from the Woods Hole Oceanographic Institution. She is a firm believer that science is for everyone and that just about everything can be viewed through the lens of science.