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News Releases
Ocean Surface Topography Mission/Jason 2 Begins Mapping Oceans
July 30, 2008
PASADENA, Calif. – Less than a month after launch, the NASA-French
space agency Ocean Surface Topography Mission (OSTM)/Jason 2
oceanography satellite has produced its first complete maps of
global ocean surface topography, surface wave height and wind speed.
The new data will help scientists monitor changes in global sea level
and the distribution of heat in the ocean. This information is used to
monitor climate change and ocean circulation, and to enable more accurate
weather, ocean and climate forecasts. The data reveal patterns of sea level
anomalies, which are used by scientists to calculate the speed and
direction of ocean surface currents.
The new mission extends a 16-year continuous record of global sea level
measurements begun in 1992 by the NASA/Centre National d'Etudes Spatiales
(CNES) Topex/Poseidon mission and continued by the two agencies on Jason 1,
launched in 2001. Data from Topex/Poseidon and Jason 1 show that mean sea level
has been rising by about three millimeters (.12 inches) a year since 1993.
The new maps were generated from the first 10 days of data collected once
the new satellite, OSTM/Jason 2, reached its operational orbit of 1,336 kilometers
(830 miles) on July 4. The new satellite and its predecessor, Jason 1, are now flying
in formation in the same orbit approximately 55 seconds apart, making nearly
simultaneous measurements that are allowing scientists to precisely calibrate
the new satellite's instruments. Comparisons of data from the two satellites on
sea-level anomalies, significant wave height and ocean wind speed all show very
close correlation of all measured parameters.
"These initial observations from OSTM/Jason 2 compare very closely to those of Jason 1,"
said Lee-Lueng Fu, OSTM/Jason 2 project scientist at NASA's Jet Propulsion Laboratory,
Pasadena, Calif. "To be able to collect such high-quality science data within a month
of launch breaks previous records. It is also a direct reflection of how mature the
field of satellite altimetry has become and of the seamless cooperation of our international team."
The satellite's first radar altimeter data were acquired just 48 hours after its
launch on June 20 from Vandenberg Air Force Base, Calif., on a Delta II rocket. The
French space agency processed the first test results, followed by more advanced data
results a week after launch. The more advanced results came after calculating the
precise location of the satellite's preliminary orbits. The satellite, its instruments
and ground segment are all functioning properly. Once it has been fully calibrated and
validated, the satellite will begin providing oceanographic products to users around the world.
OSTM/Jason 2 is an international endeavor, with responsibilities for satellite development
and launch shared between NASA and CNES. CNES provided the OSTM/Jason 2 spacecraft, NASA
provided the launch, and NASA and CNES jointly provided the primary payload instruments.
CNES and the U.S. National Oceanic and Atmospheric Administration (NOAA) are responsible for
satellite operations, while JPL is managing the mission for NASA. Data processing is being
carried out by CNES, the European Organisation for the Exploitation of Meteorological
Satellites (EUMETSAT) and NOAA, depending on the type of product.
Once on-orbit commissioning of OSTM/Jason 2 is completed, CNES will hand over mission
operations and control to NOAA, which will then join with EUMETSAT to generate, archive
and distribute data products to users worldwide.
For more information about OSTM/Jason 2, visit: http://www.nasa.gov/ostm .
JPL is managed for NASA by the California Institute of Technology in Pasadena.
Media contacts: Alan Buis (818) 354-0474
Jet Propulsion Laboratory, Pasadena, Calif.
Alan.Buis@jpl.nasa.gov
Steve Cole 202-358-0918
NASA Headquarters, Washington
Stephen.e.cole@nasa.gov
2008-151
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