Artist's concept of Jason
Artist's concept of Jason
The joint NASA-French Space Agency oceanography satellite Jason is set to embark on the science phase of its scheduled five-year voyage to study ocean circulation and its effect on climate. Jason's instruments have been accurately cross-calibrated with its predecessor spacecraft, Topex/Poseidon, and the quality of its science products has been validated.

The end of the mission's calibration/validation phase paves the way for production and distribution of Jason's first official science data products sometime in February.

Dr. Lee-Lueng Fu, JPL project scientist for Jason and Topex/Poseidon, said his team is pleased with Jason's performance. "While there's still room for improvement, Jason's measurement performance has already exceeded Topex/Poseidon's," he said. "We look forward to sharing Jason data with the world scientific community in the very near future, where we expect it will have an immediate impact in providing new insights into the currently developing El Niño condition."

Jason will continue Topex/Poseidon's observations of ocean surface topography for monitoring world ocean circulation, studying interactions of the oceans and atmosphere, improving climate predictions and observing events like El Niño. Its onboard altimeter precisely maps the surface height of 95 percent of Earth's ice-free oceans every 10 days. Sea-surface heights are a measure of how much heat is stored in the ocean below. This heat influences both present weather and future planetary climate events. The spacecraft also provides continuous data on wind speed and wave height.

Launched December 7, 2001, Jason now complements the Topex/Poseidon oceanography satellite, launched in August 1992. Last August, Topex/Poseidon was maneuvered to an orbit halfway between its original orbits, which are now being covered by Jason. The two satellites are now performing a tandem mission that will enable improved detection of ocean eddies, coastal tides and currents.

The U.S. portion of the Topex/Poseidon and Jason missions is managed by JPL for NASA's Earth Science Enterprise, Washington, D.C. Research on Earth's oceans using Topex/Poseidon and Jason and other space-based capabilities is conducted by NASA's Earth Science Enterprise to better understand and protect our home planet.

More information about Jason and Topex/Poseidon is available at:

The California Institute of Technology in Pasadena manages JPL for NASA.

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