Images & Animations
-
Credit
TOPEX/Poseidon, NASA JPL
The cold pool of water in the Pacific known as 'La Nina' still persists, although it is slowly weakening, according to scientists studying new data from the U.S.-French TOPEX/Poseidon satellite. A new image, produced using sea-surface height measurements taken by the satellite, is available on the Internet at http://www.jpl.nasa.gov/elnino/ . It shows sea-surface height on February 27, 1999 relative to normal ocean conditions, reflecting the heat content of the ocean.
The low sea level or cold pool of water along the equator (shown in purple and blue), commonly referred to as La Niqa, still dominates the equatorial Pacific Ocean. This La Nina, which first appeared in May through June 1998, still persists, although it is slowly weakening, scientists say. Given its persistence and present strength, the ocean cooling trend is expected to continue to exert a strong influence on global climate systems throughout the spring and into the early summer. This situation is similar to the 1997-1998 El Niqo, which extended into early summer 1998. The world's oceans are the great reservoirs of heat that influence global climate because they can cool or heat the atmosphere above. This transfer of heat drives weather patterns across both land and sea. La Nina provides a physical link connecting the large, slow changes in the ocean with predictable changes in day-to-day weather.
The image also shows that the very large, unusual area of higher or warmer water (shown here in red and white) in the western Pacific Ocean, from the tropics to the Gulf of Alaska, continues to expand. Although the appearance of this feature is not fully understood, it is recognized as influential to overall weather and climate. The white areas in the image indicate that the sea-surface height is between 14 and 32 centimeters (6 to 13 inches) above normal; in the red areas, sea-surface height is about 10 centimeters (4 inches) above normal. The green areas indicate normal conditions. The purple areas are between 14 to 18 centimeters (6 to 7 inches) below normal, and the blue areas are between 5 to 13 centimeters (2 to 5 inches) below normal.
The TOPEX/Poseidon mission is managed by the Jet Propulsion Laboratory for NASA's Office of Earth Science, Washington, DC. JPL is a division of the California Institute of Technology, Pasadena, CA.
Metadata
-
Sensor
TOPEX/Poseidon -
Visualization Date
1999-02-27
