The ice sheets of Greenland and Antarctica have lost a lot of ice over the past 16 years due to climate change, melting and causing sea level rise, according to a new paper,media reported. The researchers used satellite measurements, which were made by catapulting the mass of laser outbreaks on the Earth’s surface.
Since its launch on the ULA Delta II rocket in 2018, NASA’s IceSat-2 has been working “tirelessly” to measure our changing Earth. The advanced spacecraft carries a single scientific instrument — — advanced terrain laser altimeter system, also known as ATLAS.
ATLAS is able to emit 10,000 laser pulses per second that eject from below the Earth and are collected by the ICESat-2 receiving telescope. By recording the time it takes for photons to return to spacecraft and comparing the data with the probe’s precise orbital position, NASA was able to calculate the height of the Earth’s landscape with astonishing accuracy.
In the new study, the researchers used data from the ICESat-2 mission and combined it with data from its predecessor, ICEsat, which was active between 2003 and 2009, to determine exactly how the huge ice sheets and ice shelves in Antarctica and Greenland have changed over time.
“If you look at a glacier or ice sheet for a month, or a year, you don’t know much about the climate’s impact on it,” said study lead author Benjamin Smith, a glaciologist at the University of Washington. “With a 16-year time horizon between ICESat and ICESat-2, we can be more confident that the changes we are seeing are related to long-term changes in the climate.” “
The team obtained topographic data detailing the height of the ice and ice shelf from ICESat and superimposed observations from the ICESat 2 satellite in 2018/19. Where the data sets intersect, the team was able to calculate the loss or increase of the ice, taking into account factors such as snow density. Satellite observations show that Greenland’s coastal glaciers are significantly thinner, with some areas losing 14 to 20 feet (4 to 6 meters) of height each year. Rising summer temperatures have been found to melt large amounts of ice, while warmer oceans have eroded sea ice lines in some areas.
On the contrary, the thickness of the ice in some parts of Antarctica, mainly inland Antarctica, was found to have increased due to heavy snowfall. However, this increase is dwarfed by the loss of sea ice.
Melting ice shelves does not directly lead to sea level rise, as they are already floating in the ocean. But they do act as a blocker, slowing the flow of ice into the sea. On the weaker continental shelf, ice flows to the ocean at a faster rate, accelerating sea level rise. The Crosson and Thwaites ice shelves in West Antarctica were found to be thin tinted by an average of 3 m (10 ft) and 5 m (16 ft) per year, respectively.
Overall, the researchers estimate that Greenland loses an average of 200 gigatonnes of ice per year, while Antarctica’s ice melts 118 gigatonnes of ice each year. According to a press release from the University of Washington, a gigaton of ice is enough to fill 400,000 Olympic pools. The study’s authors say ice loss has caused sea levels to rise by about 14 millimeters (0.55 inches) since 2003.
The paper has been published in the journal Science.