Antarctic sea ice reaches another record low – USA TODAY
Sea ice around Antarctica reached a record low for the second straight year this month, scientists from the National Snow and Ice Data Center announced Monday.
“Antarctic sea ice has likely reached its minimum extent for the year, at 691,000 square miles on February 21, 2023,” the data center said in a news release.
The 2023 ice minimum is the lowest since records began in 1979. This year’s minimum extent beat the previous record low set last year by 52,500 square miles, an area roughly the size of the state of Alabama.
“Antarctica’s response to climate change has been different from the Arctic’s,” said Ted Scambos, senior research scientist at the Cooperative Institute for Research in the Environmental Sciences and a contributor to the data center’s Arctic Sea Ice News and Analysis page.
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“The downward trend in sea ice may be a signal that global warming is finally affecting the floating ice around Antarctica, but it will take several more years to be confident of it,” Scambos said.
What is sea ice?
Sea ice is frozen ocean water that melts each summer, then refreezes each winter. Antarctic sea ice is typically at its smallest in late February or early March, toward the end of summer in the Southern Hemisphere.
Scambos added that “lower sea ice extent means that ocean waves will pound the coast of the giant ice sheet, further reducing ice shelves around Antarctica.”
A clear sign of global warming?
Sea ice loss – especially in the Arctic and less so in the Antarctic – is one of the clearest signals of global warming, the National Climate Assessment reported in 2018.
In addition to human-caused warming of the Earth’s atmosphere and oceans, multiple factors – including the geography of Antarctica, the region’s winds, as well as air and ocean temperatures – affect the ice around Antarctica.
But it’s ‘not statistically significant’
Although the sea ice around Antarctica is undergoing a downward trend over the past decade or so, it’s “not statistically significant,” the data center said. This is in stark contrast to the Arctic, where the trend in the sea ice minimum is larger in magnitude and has strong statistical significance.
The data center said that even though sea ice occurs primarily in the polar regions, it influences our global climate and weather patterns around the world.
Scientists stress that the Antarctic sea ice number released Monday is preliminary: continued melt conditions could still push the ice extent even lower.