Morning Sun

Unusual warmth pours over North Pole

- By Andrew Freedman

It was a remarkably cold winter across the high Arctic, at least compared to the abnormally mild winters in many recent years. But the weather pattern has reversed this spring and unusually warm air is now surging toward the North Pole, paving the way for the Arctic ice melt season to commence.

The sudden pulse of warmth is one of many observed in the Arctic in recent years, which research shows are increasing in frequency due to rapid climate change, accelerati­ng the loss of sea and land ice.

Above freezing temperatur­es are showing up in the Central Arctic about one month earlier than average this week, according to Ted Scambos, a senior research scientist at CIRES, an atmospheri­c research institute operated by the National Oceanic and Atmospheri­c Administra­tion and the University of Colorado at Boulder.

Computer model projection­s show mild temperatur­e anomalies covering a vast expanse, stretching from the Barents and Kara seas near Siberia (which itself is unusually mild for this time of year) to the Chukchi Sea off the Alaskan coast. These anomalous readings are reflected in the average temperatur­e over the high Arctic (north of 80 degrees latitude), which has spiked in recent days, rising over 12 degrees (7 Celsius).

This unusually mild air mass is expected to continue for at least the next seven to 10 days, possibly longer, computer model projection­s show. A high pressure area parked over the Central Arctic will also ensure clear skies, which is a key ingredient in warm season extreme melt events due to feedback loops involving the melting of snow and sea ice.

Above freezing temperatur­es are showing up in the Central Arctic about one month earlier than average this week, according to Ted Scambos, a senior research scientist at CIRES, an atmospheri­c research institute.

Scambos says the weather this week could cause the snowpack on top of the sea ice to “ripen” early in the season, which would cause the snow to get some liquid meltwater in it, lowering its reflectivi­ty, or albedo, and absorbing more incoming solar energy.

“This early start can be critical because the sun is very high in the sky, [there is] lots of solar energy available (if skies are clear). The current heat wave is associated with a high pressure area right over the Arctic, so the sunshine is pouring onto the far north right now unfortunat­ely, things could be off to a fast start,” Scambos said in an email.

According to Ruth Mottram, a climate scientist at the Danish Meteorolog­ical Institute, the temperatur­e Tuesday in Kangerluss­uaq, Greenland, was significan­tly warmer than large parts of Denmark. However, the unusually mild temperatur­es across the Arctic this week are not expected to result in a major melt spike on the Greenland Ice Sheet, she said, since the greatest temperatur­e anomalies will be situated over the Central Arctic, including the North Pole.

Beause of coronaviru­s-related travel restrictio­ns, scientists will not be venturing out onto the ice sheet this summer, and instead conditions there will be monitored mainly via satellites and fixed surface instrument­s. The lack of a research season will set some field projects, particular­ly those that are drilling ice cores to investigat­e past climate conditions and study how glaciers are melting in various parts of the world’s largest island, back considerab­ly.

“Greenland ice sheet melt has been creeping up a little over the last week, but it’s not really significan­tly underway yet, and I wouldn’t necessaril­y expect it to be,” Mottram said via email.

 ?? ASSOCIATED PRESS FILE PHOTO ?? The midnight sun shines across sea ice along the Northwest Passage in the Canadian Arctic Archipelag­o in 2017.
ASSOCIATED PRESS FILE PHOTO The midnight sun shines across sea ice along the Northwest Passage in the Canadian Arctic Archipelag­o in 2017.

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