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Home / Science / The Antarctic sea ice is at record low again, and nobody knows why

The Antarctic sea ice is at record low again, and nobody knows why



Image: NASA Scientific Visualization Studio

What happens to Arctic sea ice is pretty simple: the earth is getting warmer and everything is melting. On the other side of the planet, however, things are more complicated, as the recent collapse of Antarctic sea ice shows, with scientists scratching their heads.

The Antarctic rang in the new year with record low sea ice gene an update that was released on Thursday by the National Snow and Ice Data Center (NSDIC). On January 1, sea ice in the Southern Ocean covered only 2.11 million square kilometers of water that washed around the continent, which is 726,000 square kilometers below the long-term average of that date. This bizarre start in 2019 followed the fastest rise in sea ice loss in December in December, which overshadowed the record lows of the Antarctic two years ago in the Australian summer of 2016-2017.

"Especially the months November to December The period 2016 was considered to be an extreme eruption of Antarctic sea ice," wrote the NSDIC.

One might think: Duh, that's climate change. And that could be part of it! An analysis conducted after the 2016-2017 sea-ice crisis, which reached a record seasonal sea-ice minimum in March 2017, concluded that a wave of unusual weather coincides with an extremely negative phase of Southern Annular Mode, in which the western wind circling the continent wandered north, was to blame.

In short, the scientists put the last sea-ice flight on natural variability. However, it is currently unclear what is behind this ice crash. Cecilia Bitz, a researcher on the sea ice of the University of Washington, told Earther that Southern Annular Fashion is currently not strongly negative. We also do not have the hangover of a monster El Niño, as we were at the end of 2016.

"I think we need to go back to the drawing board for a bit," Bitz told Earther.

Sea ice concentration and anomaly maps for December 31, 2018
Image: NSIDC | Phil Reid, Australian Bureau of Meteorology

Bitz was reluctant to speculate as to whether the near sea ice breakages are part of a new climate change-related trend. While parts of the Antarctic definitely feel the heat, until recently Antarctic sea ice has grown slightly, reaching a record high in 2014. As a result, the heating trend is not negated. It only speaks to the complexity of sea-ice behavior in an affected environment of both ocean currents and a huge continent.

Son Ngheim, a senior scientist at NASA's Jet Propulsion Laboratory told Earther that anything driven by the Antarctic continental topography, up to currents controlled by the shape of the ocean floor in the Southern Ocean, is Antarctic Sea ice influences. Bitz pointed to the melting of ice on the edges of the continent as a factor that could paradoxically help the new sea ice form by preventing warmer deep water from rising to the surface. According to NASA, snowfall could also affect the variability of the ice from year to year.

"Another point of the low ice extent in Antarctica this year can still not be considered as a climatic trend," Ngheim wrote in an e-mail in an e-mail Also in the early part of the satellite dataset, it came to record lows.

If not otherwise, the icy craze will certainly inspire additional research. ICESat-2, NASA's recently launched ice tracking satellite, could be an important indicator of ice age and health because of its ability to measure the thickness of sea ice.

Meanwhile, global sea ice cover continues to decline, with rapid losses in the Arctic far overlapping events around the southern continent.


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