Abrar Hussain: Nasa has launched a sophisticated satellite to collect data on how quickly humans are melting Earth’s ice and expanding the seas.
Every 91 days, the $1bn, state-of-the-art satellite will orbit over 1,000 paths. The satellite, about the size of a Smart car, will point six lasers at ice sheets in the Arctic and Antarctica. It will then calculate how long the beams take to bounce back. Nasa will be able to more accurately measure the heights of ice sheets and the thickness of remaining sea ice. “With sea ice, we’ve been able to measure the extent (or area) really well since about 1980 … but what we haven’t been able to measure is the thickness,” said Tom Neumann, Nasa’s deputy project scientist for the mission.
“Thickness is a key piece of the puzzle because thinner sea ice is broken up more easily by storms. It melts faster. So it gives you some insight into why the area is changing the way it is.”
According to Nasa, melting ice in Greenland and Antarctica has increased global sea levels by more than a millimeter per year, a third of the overall increase. Nasa warns that sea-level rise is speeding up, and seas could be several feet higher by the end of the century.
The IceSat-2, launched Saturday, replaces an original satellite that has been out of commission since 2009. Between 2003 and 2009, the measured sea ice lost 40% of its thickness, Neumann revealed.
Since then, Nasa has used a plane to take more rudimentary measurements of ice melt for about a month per year in the Arctic and Antarctic. That covered less ground but allowed Nasa to monitor the fastest changing parts of the ice sheets and sea ice.
Neumann said it’s possible the satellite will find ice loss beyond what Nasa has measured so far. Gaps in data, including in east Antarctica, could show ice shrinking or growing.
-Source: The Guardian