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The latest U.S.-French TOPEX/Poseidon satellite imagery
shows the persistent La Nina pattern continues to dominate the
Pacific Ocean in a very similar manner to this time last year.
For more than a year now, lower than normal sea-surface heights,
indicating cooler temperatures, have continued along the coasts
of the Americas and have spread out into the tropical ocean. In
contrast are the higher than normal sea-surface heights that show
warmer temperatures dominating the entire western Pacific.

These TOPEX/Poseidon data, collected over the latest 10-day
sampling cycle, March 1 to 11, 2000, show the La Nina condition
still exists. See . The image of
sea surface heights reflects unusual patterns of heat storage in
the ocean. Sea-surface height is shown relative to normal height
(green). The cooler water (blue and purple) measures between 8
and 24 centimeters (3 and 9 inches) lower than normal. The giant
horseshoe of warmer water (red and white) continues to dominate
the western Pacific with higher than normal sea-surface heights
between 8 and 24 centimeters (3 and 9 inches).

This view of the oceans from TOPEX/Poseidon is an input to
the National Oceanic and Atmospheric Administration (NOAA)
seasonal forecasts. The impacts of current ocean conditions in
the Pacific for spring in the U.S., according to Dr. Ants
Leetmaa, director of NOAA’s Climate Prediction Center, imply
drier than normal conditions for much of the southern half of the
U.S. Leetmaa says the conditions also indicate above-normal
rainfall in the Pacific northwest, and a warmer than normal U.S.,
except for the west coast where spring conditions will be near
normal. (NOAA seasonal forecasts can be found on .)

Scientists continue to debate whether this image hints at
the presence of a large, longer lasting climate pattern, the
Pacific Decadal Oscillation. This long-term pattern that covers
most of the Pacific Ocean has significant implications for global
climate, especially over North America. See a January press
release on that topic at

The TOPEX/Poseidon mission is managed by the Jet Propulsion
Laboratory for NASA’s Earth Science Enterprise, Washington, D.C.
JPL is a division of the California Institute of Technology,
Pasadena, Calif. For more information see .