Coldest place moves from one Antarctic site to another

SAN FRANCISCO — A swath of icy slopes in Antarctica has staked an unofficial claim as the coldest place on Earth.

Frigid pockets of air downhill from the East Antarctic plateau can chill ice surfaces to as low as –93.2°Celsius, reported Ted Scambos of the National Snow and Ice Data Center in Boulder, Colo., in a press conference at the American Geophysical Union’s fall meeting on December 9.

“It’s colder than dry ice,” said his NSIDC colleague Garrett Campbell. “If you took your glove off, your hand would freeze off very fast.”

The new low, recorded in 2010, edges out the previous record of –89.2°C, which was set at Antarctica’s Lake Vostok in 1983, several hundred  kilometers away.

The new findings have helped scientists pinpoint conditions needed to reach ultracold temperatures. Scambos, Campbell and colleagues measured surface ice temperatures using thermal sensors aboard NASA’s Landsat 8, a newly launched satellite with higher spatial resolution than previous satellites.

The chilliest spots lay along the gentle slopes of a ridge about 4,000 meters tall. On clear winter nights, air on the ridge loses heat to space, Scambos said. The dense, cold air sinks to the ground and slides down the ridge, where it can puddle in flat basins. While this pooled air rests on the ice, even more heat escapes and the ice surface cools down further.

Still, Vostok may keep its place in the record books a little longer, said polar meteorologist Michiel van den Broeke of Utrecht University in the Netherlands.

The World Meteorological Organization, the governing body that registers climate extremes, awards official records only to air temperatures measured 2 meters above the Earth’s surface, he said.

But Scambos, Campbell and colleagues measured surface ice temperatures using Earth-orbiting satellites. The Vostok record came from measurements of air just outside a research station.

“You can’t break the record from space,” van den Broeke said.

One of the new cold spots may yet beat out Vostok’s record, he added. “I’m pretty sure that if you go to one of these cold spots, you will confirm that it is actually the coldest place on Earth.”

However, the new temperature lows may be fleeting. Because scientists expect Antarctica to warm by 3 or 4 degrees before the end of the century, says John Turner of the British Antarctic Survey, “we may not get such cold temperatures again.”

Editor’s Note: This story was updated December on 11, 2013, to correct the approximate distance between locations of previous and current lowest recorded temperatures.