Reverberations of the Pacific Warm Pool


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When scientists speak of large-scale climate events such as El Niño and La Niña, they tend to use the word “anomaly.” Over the past several decades, however, such recurrent changes in the Earth’s climate appear to be anything but. In fact, the more researchers study the Earth’s oceans and atmosphere, the more they are finding that such large-scale cyclical and near-cyclical variations in ocean temperature and air pressure appear to occur all across the planet at many time scales. Some can stir up the weather across half the globe, while others may only affect the coasts of a single country. Some recur twice every decade on average, while others come around every year.


Climate Oscillations:
Introduction: El Niño’s Extended Family
Search for Atlantic Rhythms
Reverberations of the Pacific Warm Pool

Coming Soon:
Intertropical Convergence Zone


Map showing West Pacific Warm Pool


Of these anomalies, one of the most recent to be discovered takes place in the Indo-Pacific warm pool. This body of water, which spans the western waters of the equatorial Pacific to the eastern Indian Ocean, holds the warmest seawaters in the world. Scientists found that, over a period of roughly two decades, the warm pool’s average annual temperatures and dimensions increase and then decrease like a slowly pulsating beacon.

The effects and origins of these oscillating waters, however, remain something of a mystery. For the past three years researchers based at NASA’s Goddard Space Flight Center, led by atmospheric scientist Vikram Mehta, have been trying to unravel some of the questions surrounding the warm pool. They have been poring over atmospheric and sea surface temperature data from the western Pacific to the eastern United States looking for answers as to why the warm pool oscillates and what effects this oscillation may have on the world’s climate. What they found is that the warm pool’s vacillations may be felt as far away as Arkansas and may be powerful enough to broaden the extent of El Niño.

next Running Hot and Cold

The data used in this study are available in one or more of NASA's Earth Science Data Centers.


Sea Surface Temperature Palette

The Indian Ocean/West Pacific Warm Pool extends almost half way around the globe, stretching along the equator south of India, through the waters off Sumatra, Java, Borneo, and New Guinea, and into the central Pacific Ocean. The waters of the Warm Pool are warmer than any other open ocean on Earth. Because these waters are hot enough to drive heat and moisture high into the atmosphere, the warm pool has a large effect on the climate of surrounding lands. In fact, the slow fluctuations of size and intensity of the warm pool may be linked with the intensity of El Niño.