Arctic

The peak extent of this year's Arctic sea ice appears to be the lowest on record

Arctic sea ice has likely reached its peak for this winter season, and if so, it represents a concerning new record, scientists said Monday.

The ice "appears to have reached its annual maximum extent on March 24, and is now the lowest maximum in the satellite record, replacing last year's record low," the National Snow and Ice Data Center said in a statement.

While the year's maximum extent was hit later than average, a late-season surge in ice growth remains possible, the Colorado-based center said.

The likely new record doesn't come as a surprise.

The low maximum ice extent follows record lows in January and February. It also follows months of record-high temperatures in the Arctic.

Earlier this month, a University of Alaska Fairbanks scientist had said there was a good chance that this year's sea-ice minimum will be a record low. The winter weather and ice patterns are similar to those of 2007, the year when ice hit its second-lowest minimum, said Xiangdong Zhang of UAF's International Arctic Research Center.

This year's record-low maximum beat a mark set just last year.

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Last year's ice extent topped out at 14.537 million square kilometers, or 5.61 million square miles. The 2015 melt season started early that year, with a maximum extent reached on Feb. 25 of that year, the second-earliest maximum in the satellite record, which started in 1979.

This winter's ice conditions -- with the maximum extent coming in at a level more than 7 percent lower than the 1981-2010 average -- also sets things up for a low minimum at the end of the summer melt season, scientists have said.

"We know that we're starting off on a bad footing," said Mark Serreze, director of the National Snow and Ice Data Center.

The center is still analyzing the age of the winter ice, a characteristic that correlates to thickness and resilience, and will present that information soon, Serreze said. It is unlikely that the ice is thick, he said.

This winter's extent was particularly low in the Barents Sea and the Kara Sea on the Atlantic side, which Serreze said is a pattern that has appeared in recent years.

There is evidence that underwater heat is being drawn north in winter at that point on the globe, he said. "There's a lot of work about how ocean-heat transport in the Barents Sea has been a big player in this," he said. It might be a temporary phenomenon that ends in the next few years, meaning a possible rebound in winter, though not in summer, he added.

The record-low maximum ended a fairly erratic pattern of winter ice growth that featured a long stall in February after what appeared at the time to be a very early peak in extent.

Ultimately, the amount of melt that happens this summer will depend on weather, Serreze said. He noted that maximum extent at the end of winter does not always correlate to minimum extent at the end of summer.

In 2012, for example, winter ice extent was relatively high, but the summer melt was so dramatic that it created the all-time record low minimum that September.

For some Arctic watchers, the new record-low maximum is a significant milestone.

"The most important thing about this is it's another indication of the unraveling of sea ice and the Arctic," said Rafe Pomerance, a former U.S. Department of State official who is now a member of the Polar Research Board and who chairs a coalition of nonprofit groups called Arctic 21. "That's what these records are -- they are exclamation points along a trend."

Sea ice trends are now getting attention far south of the Arctic, Pomerance said. He cited an upcoming conference hosted by Florida Atlantic University titled "Connected Futures from Alaska to Florida" that will examine Arctic climate change and its effects on the south.

Yereth Rosen

Yereth Rosen was a reporter for Alaska Dispatch News.

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