It is not a fantastic 12 months for polar sea ice. Each the Arctic and Antarctic have seen record lows in sea ice extent, in accordance with NASA and the National Snow and Ice Data Center (NSIDC), which use satellite data to trace sea ice across each polar regions.
Arctic sea ice likely reached its annual minimum extent this 12 months on Sept. 19 at 1.63 million square miles (4.23 million square kilometers) — the sixth-lowest minimum within the satellite record. And in Antarctica, sea ice likely reached its maximum extent on Sept. 10 at 6.5 million square miles (16.96 million square kilometers) — the bottom maximum ever within the satellite record.
“It’s a record-smashing sea ice low within the Antarctic. Sea ice growth appears low around nearly the entire continent versus anybody region,” Walt Meier, a sea ice scientist at NSIDC, said in an announcement. And within the Arctic, he points out, the Northwest Passage has more open seas than usual.
“There also appears to be so much more loose, lower concentration ice — even toward the North Pole — and areas that was pretty compact, solid sheets of ice through the summer,” he said. “That’s been happening more regularly lately.”
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Annually, sea ice grows and melts with the seasons, and its extent in each directions might be impacted by aspects like wind patterns, ocean temperatures — directly correlated with human-induced global warming — and climate patterns like El Niño, which is happening now.
One among the problems with low sea ice coverage is that it reinforces ocean warming on account of the ice-albedo feedback cycle. Sea ice, being white, reflects the sun’s energy back out into space, but dark open ocean absorbs it — as such, the waters may remain warmer, inhibiting sea ice growth further.
And while sea ice minimum and maximum extents are key measurements within the polar environment, the thickness of that sea ice is one other major concern.
“Thickness at the tip of the expansion season largely determines the survivability of sea ice. Latest research is using satellites like NASA’s ICESat-2 (Ice, Cloud and land Elevation Satellite-2) to watch how thick the ice is year-round,” said Nathan Kurtz, lab chief of NASA’s Cryospheric Sciences Laboratory on the agency’s Goddard Space Flight Center.
“At NASA we’re keen on taking cutting-edge measurements, but we’re also attempting to connect them to the historical record to raised understand what’s driving a few of these changes that we’re seeing,” said Kurtz.