The latest measurements of sea surface height made by the TOPEX/Poseidon satellite show the tropical Pacific Ocean with a stalled La Nina condition coexisting with the remnants of last year's El Nino event.
"The forecasted intensification of this La Nina for fall 1998 and into winter 1999 has yet to live up to its billing. The size and heat content of this cold pool of water has remained remarkably stable for the past five months since El Nino began to dissipate in mid-June 1998," said Dr. Bill Patzert, a research oceanographer at NASA's Jet Propulsion Laboratory.
The image shows sea-surface height on November 8, 1998, relative to normal ocean conditions. Sea surface height is an indicator of the heat content of the ocean. Remnants of the high sea level, warmer El Nino waters still linger to the north of the equator -- while the area of low sea level, or cold water that is sometimes referred to as La Nina, remains in the center of the Pacific. Oceanographers believe that the coexistence of these two contrasting conditions indicates that the ocean and the climate system have not recovered from the record-breaking warming that has occurred during the past two years.
A La Nina is essentially the opposite of an El Nino condition, but during a La Nina the trade winds are stronger than normal and the cold water that normally exists along the coast of South America extends to the central equatorial Pacific. Like El Nino, a La Nina situation also changes global weather patterns and is associated with the possibility of more winter storms entering North America in the Pacific Northwest and with less precipitation anticipated for Southern California and the Southwestern United States.
The November 8 image is now available online at:
The U.S.-French TOPEX/Poseidon mission is managed by NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena, CA, for NASA's Earth Sciences Enterprise, Washington, DC.
The above post is reprinted from materials provided by NASA/Jet Propulsion Laboratory. Note: Materials may be edited for content and length.
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