El Nino is a warming of surface water of the equatorial Pacific Ocean that usually occurs around December every three to six years. It disrupts weather worldwide, causing storms, floods and droughts. Its exact arrival, however, is extremely difficult to predict with precision because of El Nino's chaotic nature. A particularly significant El Nino (Spanish for "The Child," referring to the infant Jesus) appears to be brewing in the equatorial Pacific right now, threatening to strike some time later this year.
"Control" of El Nino's chaotic behavior has now been achieved in a sophisticated computer simulation. The study, reported in Physical Review Letters (August 11, Vol. 79, p.1034), was conducted by Prof. Eli Tziperman of the Weizmann Institute's Environmental Sciences and Energy Research Department, together with departmental colleague Dr. Harvey Scher and with Dr. Stephen Zebiak and Prof. Mark Cane of Columbia University's Lamont- Doherty Earth Observatory.
The scientists worked with a computer model currently used to predict El Nino events. When they altered the values for the magnitude of deep ocean waves at a single point in the western Pacific, the model produced El Nino at regular intervals of about four years, with perfectly predictable cycles of temperature, winds and ocean currents.
While the scientists don't propose to control the actual El Nino, they do believe that the successful control in a complex prediction model may help them better understand the crucial factors governing El Nino's behavior. This, in turn, may improve the researchers' ability to predict El Nino events, leading to measures that would reduce their global damage.
Prof. Tziperman holds the Barry Rymer Chair for Environmental Research. His research was partially supported by the U.S.-Israel Binational Science Foundation and by the Sussman Family Center for the Study of Environmental Sciences at the Weizmann Institute.
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Journal
Physical Review Letters