NASA satellite launched to monitor global warming

US and French scientists launch Jason-3 satellite, capable of tracking currents and sea levels in unprecedented detail.


    US and French scientists have launched a new satellite capable of measuring the height of the world’s oceans to within 4cm.

    The $180m mission, named Jason-3, is expected to provide them with vital data to track long-term changes to climate and the ocean’s role in global warming.

    Jason-3 was launched on top of a SpaceX Falcon 9 rocket from Vandenberg Air Force Base in California on Sunday. 

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    The satellite will map the hills and valleys of the ocean surface from orbit, 1,300km above the earth.

    "Over 90 percent of the heat trapped by greenhouse gases is warming the ocean," said Josh Willis, oceanographer and mission scientist at NASA's Jet Propulsion Laboratory.

    "That causes the water to expand and get taller."

    Melted water from warming glaciers and ice sheets adds to rising sea levels, making their precise long-term measurement important.

    "These two things together really provide a global footprint of human-caused climate change in a way that no other indicator or measurement does," Willis said.

    Travelling at more than 6km per second, the satellite will be able to return data from every point on the globe every 10 days.

    "There's a radar attached to the satellite," Willis said.

    "It bounces a radar wave off the surface of the ocean and measures how long it takes to go down and come back. This gives us a very simple estimate of the distance between the satellite and the ocean."

    Understanding El Nino

    Tracking the height of the ocean is also important for understanding the development of the El Nino weather pattern which, in the past year, has seen parts of the Pacific Ocean warm up, upsetting weather patterns and resulting in strong storm systems.

    "Hurricanes are intensified when they pass over warm water," Willis said.

    "That is not just warm at the surface but over a depth. When you have water that's warm over an entire depth of the ocean it actually raises sea level and we can measure that by satellite."

    Sunday's launch provided the private space company SpaceX with the opportunity to test new landing technology that it has been trialling in its rockets.

    After carrying the satellite high into the atmosphere, the company attempted to successfully land the first stage of the rocket on a barge off the Californian coast, an industry it claims could first result in dramatically cheaper space travel by making rockets reusable.

    The company announced, however, that while the first stage had been on target - it landed heavily and "broke [its] landing leg".

    It tried the same manoeuvre in April 2015, but a problem with a valve resulted in an explosion.

    Last month, SpaceX celebrated the first ever successful landing of the rocket back on its launch-pad.

    With much of the cost of launching satellites and other spacecraft coming from the cost of the rocket, the company hopes its technology will make space more accessible and exploring the solar system more affordable.

    SOURCE: Al Jazeera


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