was fishermen off the coast of Peru who first recognized the anomaly, hundreds of years ago. Every so often, their usually cold, nutrient-rich water would turn warm and the fish they depended on would disappear. Then there was the ceaseless rain.
They called it "El Nino," The Boy -- or Christmas Boy -- because of its timing near the holiday each time it returned, every three to seven years.
El Nino is not a contemporary phenomenon; it's long been Earth's dominant source of year-to-year climate fluctuation. But as the climate warms and the feedbacks that drive the cycle change, researchers want to know how El Nino will respond. A team of researchers led by the University of Wisconsin's Zhengyu Liu published the latest findings in this quest Nov. 27, 2014 in Nature.
"We can't see the future; the only thing we can do is examine the past," says Liu, a professor in the Department of Atmospheric and Oceanic Sciences. "The question people are interested in now is whether it's going to be stronger or weaker, and this requires us to first check if our model can simulate its past history.
Using state-of-the-art computer models maintained at the National Center for Atmospheric Research in Colorado, the researchers -- also from Peking University in China, the University of Hawaii at Manoa, and Georgia Institute of Technology -- determined that El Nino has intensified over the last 6,000 years.
The findings corroborate data from previous studies, which relied on observations like historical sediments off the Central American coast and changes in fossilized coral. During warm, rainy El Nino years, the coastal sediments consist of larger mixed deposits of lighter color, and the coral provides a unique signature, akin to rings on a tree.
http://www.sciencedaily.com/news/earth_climate/severe_weather/
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