Images & Animations
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Credit
TOPEX/Poseidon, NASA JPL
The North Pacific Ocean continues to run hot and cold, with abnormally low sea levels and cool waters in the northeastern Pacific contrasting with unusually high sea levels and warm waters in the northwestern Pacific.
New imagery from the joint NASA and French space agency's TOPEX/Poseidon orbiting satellite, which celebrates its 7th launch anniversary next week, shows strongly contrasting ocean levels and temperatures on opposite sides of the north Pacific. This pattern was locked in more than four months ago, when a very strong, high-pressure system began to dominate northern Pacific atmospheric and ocean patterns. Present conditions will be slow to change, according to oceanographer Dr. William Patzert of NASA's Jet Propulsion Laboratory, Pasadena, CA, and will influence climate over North America into the fall.
The latest sea-surface height measurements, available at http://www.jpl.nasa.gov/elnino/, reveal unusually cool water (shown in blue and purple) and lower sea levels (5 to18 centimeters or 2 to 7 inches below normal) extending from the Gulf of Alaska along the coast of North America. The lower sea levels sweep south-southwest from Baja California, to merge with the remnants of La Nina. Cool, lower equatorial sea levels from La Nina remain weak, but are still evident along the equator. On the other side of the north Pacific, sea levels remain high (10 to 32 centimeters or 4 to 13 inches above normal) and temperatures are warm (shown in red and white). Normal sea levels appear in green. The data were collected on a 10-day data-gathering cycle taken July 18-27.
Since its launch on August 10, 1992, TOPEX/Poseidon has performed nearly flawlessly, collecting information about the height of the sea's surface at an unprecedented accuracy of 4 centimeters (15 inches). Using this information, scientists from NASA and the Centre National d'Etudes Spatiales have been able to map and forecast the impact of the 1997- 1998 El Nino and the La Nina that followed and continues to hang on.
Although La Nina appears to be waning, Patzert added, the ocean abnormality is probably not gone for good. 'La Nina might be temporarily down, but she's definitely not out,' he said. 'What we are seeing from space in these wildly fluctuating sea levels and temperature variations is a continuing hangover from La Nina.'
The U.S./French TOPEX/Poseidon mission is managed by the Jet Propulsion Laboratory for NASA's Office of Earth Sciences, Washington, DC. JPL is a division of the California Institute of Technology, Pasadena, CA.
Metadata
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Sensor
TOPEX/Poseidon -
Visualization Date
1999-07-27
