Washington: Antarctic Sea ice extent has reportedly broken last year’s record, and it set the record earlier than last year, according to a statement. National Snow and Ice Data Center (NSIDC).
On February 13, 2023, the extent of Antarctic sea ice dropped to 1.91 million square kilometers, it said.
It hit a new record low, falling below the previous record of 1.92 million square kilometers set on February 25, 2022, it said.
This year represents only the second year that Antarctic extent has fallen below 2 million square kilometers, the statement said.
In previous years, the annual minimum occurred between February 18 and March 3, hence, further decline is expected this year, it said.
With perhaps a few more weeks left in the melting season, the range is expected to drop further before reaching annual minimums, it said.
Much of the Antarctic coast is ice-free, exposing ice shelves that connect the ice sheet to wave action and warm conditions, the statement said.
NSIDC is a US information and referral center in support of polar and cryospheric research.
NSIDC is part of the Colorado Boulder Cooperative Institute for Research in Environmental Sciences (CIRES), and is affiliated with the National Oceanic and Atmospheric Administration (NOAA) National Center for Environmental Information through a cooperative agreement.
Sea ice extent has tracked well below last year’s melt season levels since mid-December, according to the NSIDC statement.
A positive southern annular mode is a stronger than average westerly wind. Along with a strong Amundsen Sea low, weather conditions have brought warm air to regions on both sides of the Antarctic Peninsula, the statement said.
This has largely cleared the ice cover in the Amundsen and Bellingshausen seas and reduced sea ice extent in the northwestern Weddell Sea, NSIDC said.
Sea ice is isolated and almost absent along long stretches of Antarctica’s Pacific coastline, NSIDC said.
Previous studies have linked low sea ice cover to wave-induced stress on the continent’s floating ice shelves, which breaks up weak areas, the statement said.
Antarctic sea ice extent has been highly variable over the years. While there were record lows in 2022 and 2023, four of the five highs since 2008 have been lows, NSIDC said.
Overall, the Antarctic minimum range trend is close to zero between 1979 and 2023, NSIDC said.
The current downward linear trend in Antarctic sea level from 1979 to 2023 is 2,400 square kilometers per year, or 0.9 percent per decade, which is currently not statistically significant, NSIDC said.
Nevertheless, the sharp decline in sea ice extent since 2016 has fueled research into potential causes and whether sea ice loss in the Southern Hemisphere is developing a significant downward trend, the statement said.