Data collected by a sophisticated satellite just launched by NASA means that the world will soon have a much clearer idea of how quickly humans are melting Earth's ice and expanding the seas.
Every 91 days, the decade's creation, which cost US $ 1 billion to manufacture, will orbit more than 1,000 different routes.
The satellite, about the size of a car, will target six lasers in the ice sheets in the Arctic and Antarctic.
It will then calculate how long it takes for the beams to recover, with the result that NASA will be able to more accurately measure the heights of the ice sheets and the thickness of the 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 Dr. Tom Neumann, NASA's associate project scientist for the mission. The Guardian.
“Thickness is a key piece of the puzzle because thinner sea ice is broken more easily by storms. It melts faster. So it gives you an idea of why the area is changing the way it is. "
Melting ice in Greenland and Antarctica has raised global sea levels by more than a millimeter a year, a third of the overall increase, according to NASA.
Sea level rise is getting faster and faster, and seas could be a meter higher by the end of the century.
The IceSat-2 replaces an original satellite that has been out of service since 2009.
Between 2003 and 2009, the measured sea ice lost 40 percent of its thickness, Dr. Neumann said.
Since then, NASA has used a plane to take more rudimentary ice melt measurements for about a month per year in the Arctic and Antarctic.
That covered less ground but allowed NASA to monitor the most changing parts of the ice sheets and sea ice.
Dr Neumann said that it is possible that the satellite will encounter an ice leak beyond what NASA has measured so far.
Gaps in the data, even in East Antarctica, could show a decrease or increase in ice.
The new satellite will provide coverage and a more complete measurement in one centimeter.
"In the time it takes for someone to blink, half a second, IceSat-2 will collect 5000 measurements in each of its six beams, and that is going to do every hour, every day, it's a huge amount of data," said Dr. Neumann.
NASA has an entire fleet of satellites that observe Earth, even looking for signs of climate change.
Original article (in English)