الاثنين، 18 يناير 2016

NASA satellite launched to monitor global warming - Rawan For Media Artistic and Production

NASA satellite launched to monitor global warming - Rawan For Media Artistic and Production

 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.
Inside Story: Are US space missions running out of steam?

The satellite will map the hills and valleys of the ocean surface from orbit, 1300km 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 last 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 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 first it claims could result in
dramatically cheaper space travel by making rockets re-usable.


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 maneuver in April 2015, but a problem with a valve resulted in an explosion.

Last month, SpaceX celebrated the first ever successful landing 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

ليست هناك تعليقات:

إرسال تعليق