Scientists studying data from the TOPEX/Poseidon satellite have observed an ocean phenomenon in the equatorial Pacific that indicates a new El Nio event may occur in late February or early March off the western coast of South America.
The scientists have been analyzing a prominent Kelvin wave which has appeared in recent TOPEX/Poseidon altimeter data. A Kelvin wave is a large warm water mass that moves along the equator in the Pacific Ocean, and such Kelvin wave pulses sometimes give rise to El Nio conditions in the eastern equatorial Pacific. The same Kelvin wave pulse that was seen in the TOPEX/Poseidon data was predicted by the global ocean numerical models developed on supercomputers at the Naval Research Laboratory.
This particular Kelvin wave pulse, which was excited by westerly wind anomalies in the western Pacific in December 1992, is projected to arrive at the South American coast in late February or early March. The analysis of the TOPEX/Poseidon data indicates an arrival in the early part of the window, while the Navy model points to a slightly later date. The imminent arrival of this Kelvin wave pulse suggests that the current warm conditions in the eastern Pacific will continue or possibly intensify during March.
JPL manages the NASA portion of the joint U.S./French TOPEX/Poseidon mission for the Earth Science and Application Division. Launched Aug. 10, 1992, it is the second satellite in the Mission to Planet Earth program, a long-term effort to study Earth as a global environmental system.
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