France, NASA satellite to map rising sea levels

BEIJING, May 22 (Xinhuanet) -- If all goes as planned, a new satellite to map Earth's rising sea levels and study their link to global climate change will be launched June 15 by France and NASA.

The Jason 2 spacecraft is set to lift off atop a Delta 2 rocket from Vandenberg Air Force in California on a joint mission to study the Earth's oceans and their currents.

"Globally, on average, sea levels are rising," said Steven Neek of NASA's Science Mission Directorate at NASA's Washington, D.C., headquarters, in a Tuesday briefing. "This is a complex phenomenon which we need to understand better through flying new spacecraft."

Since 1993, global sea levels have risen about 0.12 inches (3 millimeters) per year, or about twice the expected rate based on tide records from the past century, NASA officials said. Natural and human-made causes are responsible for the shift, Neek said.

Jason 2's Ocean Surface Topography Mission is a joint NASA-French Space Agency effort and the third in a series of satellites to track global sea levels for climate studies. The spacecraft's immediate predecessor, Jason 1, launched in 2001 and is still operating today. Another U.S.-French satellite, TOPEX/Poseidon, launched in 1992 and scanned Earth's oceans for 13 years.

"OSTM/Jason 2 will help create the first multi-decadal global record for understanding the vital roles of the ocean in climate change," said Lee-Lueng Fu, the mission's project scientist at NASA's Jet Propulsion Laboratory in Pasadena, California, in a statement.

The new 433 million U.S. dollar satellite is expected to orbit in tandem with Jason 1 some 830 miles (1,336 km) above Earth and double the amount of monitoring coverage of Earth's oceans, mission managers said.

The satellite uses ocean altimetry and other tools to measure the height of the sea surface with an accuracy of within 1.3 inches (3.3 cm). The readings are also expected to yield information on the speed and direction of ocean currents, and serve as an indicator of the amount of heat in the water that can affect climate change, mission researchers said.

(Agencies)