Antarctic Sea Ice Sets Record Low, Providing Another Mystery for Scientists

Warming at the South Pole hits record high as sea ice shrinks, a departure from its record high only a few years ago.

A colony of Adelie penguins basks near the sea ice in Antarctica
Antarctica's Adelie penguins basked in a particularly warm summer in 2015 and now live amid shrinking sea ice. Credit: Getty Images

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A new record warm temperature for Antarctica was confirmed by the World Meteorological Organization as sea ice surrounding the continent has shrunk to a record low.

The temperature reached its record high of 63.5 degrees Fahrenheit on March 24, 2015, according to an announcement by the WMO, which often takes years to verify new records.

The news came as sea ice around Antarctica is experiencing its lowest extent ever. As of March 1, only 820,000 square miles of the ocean around Antarctica was covered in ice, according to data from the National Snow and Ice Data Center in Boulder, Colo. The loss of ice represents an all-time minimum for Antarctic sea ice cover since satellite observations began in 1979.

The current decline, however, may not be part of a larger climate change trend. The low point comes less than three years after Antarctic sea ice set a record high in October 2014.  “If you look at the long-term trend, Antarctic sea ice is still increasing slightly, said Son Nghiem, a researcher with NASA’s Jet Propulsion Laboratory.

That increase has provided fodder for climate denial arguments and was a mystery to scientists because it differed so greatly from the rapid melting occurring in the Arctic. But recent research has provided clues to the reasons. The continent’s unique topography shields it from warming occurring elsewhere, Nghiem said.

A study Nghiem and colleagues published last year found that topography creates icy winds blowing off Antarctica and a powerful ocean current that circles the continent. The study, published in the journal Remote Sensing of Environment, concluded that these two factors play a larger role in the formation and persistence of Antarctic sea ice than changes in temperature.

“I think Antarctic sea ice will be stable for at least some time into the future,” Nghiem said.

That puts it in direct contrast with the Arctic, which is losing its ice at a rapid clip as it experiences a record-warm stretch and record low levels of sea ice at the North Pole. Last month temperatures in the far north were 20 degrees above normal according to data from the Danish Meteorological Institute. The ice cap over the North Pole receded to a record low in January for the second year in a row according to the National Snow and Ice Data Center.