Jason-3 launches to monitor global sea level rise
18 January 2016
Jason-3, a US-European oceanography satellite mission with NASA, has lifted off from Vandenberg Air Force Base in California aboard a SpaceX Falcon 9 rocket.
Jason-3 is an international mission led by the National Oceanic and Atmospheric Administration (NOAA) in partnership with NASA, the French space agency CNES, and the European Organisation for the Exploitation of Meteorological Satellites.
The mission is designed to improve weather, climate and ocean forecasts, including helping NOAA’s National Weather Service and other global weather and environmental forecast agencies more accurately forecast the strength of tropical cyclones.
Minutes after Jason-3 separated from the rocket’s second stage, the spacecraft unfolded its twin sets of solar arrays. Ground controllers successfully acquired the spacecraft’s signals, and initial telemetry reports showed the satellite was in good health.
Jason-3 entered orbit about 25km below its predessessor, Jason-2. The new spacecraft will gradually raise itself into the same 1,336km orbit and position itself to follow Jason-2’s ground track, orbiting a couple of minutes behind Jason-2. The two spacecraft will fly in formation, making nearly simultaneous measurements for about six months to allow scientists to calibrate Jason-3’s instruments.
Jason-3 begins full science operations after a six-month checkout phase, joining Jason-2, which launched in 2008. From low-Earth orbit, Jason-3 will precisely measure the height of 95 percent of the world’s ice-free ocean every ten days.
Coordinating orbits and combining measurements from Jason-2 and Jason-3 should allow more frequent coverage of the global oceans. Together, the two spacecraft will double global data coverage. The tandem mission is expected to improve knowledge of tides in coastal and shallow seas and internal tides in the open ocean, while improving understanding of ocean currents and eddies.
Measurements of sea-surface height, or ocean-surface topography, reveal the speed and direction of ocean currents and tell scientists how much of the sun’s energy is stored by the ocean. Combining ocean current and heat storage data is key to understanding global climate changes.
Since the Topex/Poseidon-Jason satellite missions began in 1992, researchers have observed a total global sea level rise of 70mm – an average rate of 3mm a year. Because it is a measure of both ocean warming and loss of land ice, sea level rise is an important indicator of human-caused climate change.
Data from Jason-3 will be used for other scientific, commercial and operational applications, including modelling of deep-ocean waves; forecasts of surface waves for offshore operators; forecasts of tides and currents for commercial shipping and ship routing; coastal forecasts to respond to environmental challenges such as oil spills and harmful algal blooms; coastal modelling crucial for marine mammal and coral reef research; and forecasts of El Nino and La Nina events.
Following its launch mission, the Falcon 9 rocket landed precisely and vertically on its sea barge, but was unable to repeat the successful landing of last month, as one of its support legs collapsed (possibly as a result of too heavy a landing or a mechanical fault) causing it to topple over and catch fire.