In The Last 2 Years Antarctic Sea Ice Reached Its Lowest Level

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In the past 2 years Antarctic sea ice has shrunk to its lowest level since satellite recording began more than 40 years ago. Photo/NSIDC/NASA/Live Science

COLORADO – In the past 2 years Antarctic sea ice has shrunk to its lowest level since satellite recording began more than 40 years ago. Sea ice is frozen seawater that floats on the surface of the ocean around Earth’s polar regions.

According to the National Snow and Ice Data Center (NSIDC), based at the University of Colorado Boulder (UCB), less than 772,000 square miles or 2 million square km of sea ice was recorded last year. In total, this is the lowest figure since scientists recorded the extent of sea ice with satellites in 1979.

As of February 21, 2023, that number continues to shrink to just 691,000 square miles or 1.8 million square km. This figure is approximately 40% less than the average between 1981 and 2010.

The record low level of sea ice is expected to occur after an unusually hot January, according to the National Oceanic and Atmospheric Administration. “By the end of January, we predict it will only be a matter of time (until the record low is broken),” said Will Hobbs, an expert on Antarctic sea ice at the University of Tasmania and the Australian Antarctic Program. .

It is known that sea ice forms at a much lower sustainable temperature than fresh water ice, around minus 1.8 degrees Celsius. Sea ice accumulates during the winter until it reaches a maximum, and melts in the spring and summer until it reaches a minimum.

In Antarctica, where summer and winter are reversed relative to the Northern Hemisphere, sea ice usually reaches its maximum in September. When it did, sea ice covered about 7 million square miles or 18.5 million square kilometers.

Antarctica’s minimum sea ice area is likely to continue to decrease in the coming decades as global temperatures increase. This problem is a result of human-caused climate change so that more ice will melt.

Why is sea ice important?

Sea ice is especially important for polar predators, such as penguins in Antarctica and polar bears in the Arctic, who use the ice as a platform for hunting. But sea ice also helps stabilize ice in Antarctica.

In turn, ice instability could threaten large glaciers, such as the Pine Island and Thwaites glaciers. The latter is commonly known as the Doomsday Glacier, which if it continued to melt would spell disaster.

“If these glaciers start to lose land ice more rapidly, it could trigger a dramatic increase in sea level rise before the end of the century,” said Julienne Stroeve, NSIDC senior research scientist and professor at the University of Manitoba in Canada.

Sea ice also reflects sunlight back into space, which helps cool Earth. Lower levels of sea ice reduce the portion of reflected light, called albedo, which further increases global warming.

(wib)