Satellites reveal clearer picture of melting ice in Antarctica

NASA satellites have provided more data than ever on what has been happening in Antarctica and Greenland ice in the past 16 years with dire, if not completely unexpected, findings. Both polar ice sheets lose billions of tons of ice each year and increase sea level rise.

The results revealed that while there are small ice gains in East Antarctica, they have been overshadowed by massive losses in West Antarctica, NASA reported. The net loss of ice mass has led to almost half an inch of sea level rise between 2003 and 2019, just under a third of the total sea level rise worldwide at that time.

The findings were based on information from the space agency’s ICESat and ICESat-2 satellite laser altimeters, devices that use laser pulses to measure the elevation and thickness of ice sheets and help better understand global climate change.

The researchers concluded that the Greenland and Antarctic ice masses will continue to contribute to rising sea levels that will rise in the coming decades. The Greenland ice sheet lost an average of 200 gigatons of ice per year, and the Antarctic ice sheet lost an average of 118 gigatons of ice per year, NASA reported.

An ice gigaton would cover New York’s Central Park in ice over 1,000 feet thick, at a higher height than the Chrysler Building, NASA said.

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The study, published Thursday in the journal. Science, provided estimates of the changes in ice mass on land and floating between 2003 and 2019.

Floating ice, well, it floats – it’s already in the water and it doesn’t contribute to rising sea levels. The crushed ice has not yet reached the ocean, but when the ice shelves melt and fall into the ocean, the rise in sea level increases.

“Quantifying changes in the Earth’s ice sheets and identifying climatic factors is critical to improving sea level projections,” the researchers stated.

The researchers believe that “competitive weather processes” are occurring in Antarctica. Antarctica and Greenland are losing ice mass in general, but it accumulates in some regions and disappears in others.

In Greenland and Antarctica, “losses outweighed gains”, and losses from West Antarctica account for more than 30 percent of the region’s total. It was somewhat offset in East Antarctica, where ice sheets were gaining mass with accumulated snow.