Unusual Warm Weather Spells Trouble for North

Computer projections released earlier this week showed temperatures in the North Pole rising above freezing on Wednesday, but the effects of the usual weather system have been borne by Norway’s Svalbard archipelago - and could have profound effects on reindeer and infrastructure.

Written byHannah Hoag Published on Dec. 31, 2015 Read time Approx. 5 minutes
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A low-pressure system that brought tornadoes to Dallas and heavy rainfall to the UK has also pumped warm air from southern Europe into the Arctic.

Computer projections released earlier this week had suggested that temperatures at the North Pole could rise above freezing – far greater than the -30 to -35C (-22F to -31F) typical for the region at this time of year. If it had occurred, it would have made the North Pole warmer than parts of Texas, Slate reported on Tuesday.

As climatologists collected data from a network of Arctic Ocean buoys scattered across the region, it started to look as though the storm, though unusual, would not leave any lasting effects on the winter build-up of Arctic sea ice. Meanwhile, high temperatures in Svalbard and rain raised avalanche risks and could threaten local reindeer populations.

North Pole Brushes Freezing Point

There are no weather observing stations at the North Pole, but nearby automatic data buoys drift through the Arctic Ocean collecting information on their location and the air temperature. Early Wednesday morning (Alaska time), a buoy drifting about 550 kilometers (345 miles) south of the North Pole, reported air temperatures of -0.1C (31.8F), according to the U.S. National Weather Service. Six hours later it had dropped slightly to -1.6C (29F).

“It is far, far above normal,” said National Weather Service climatologist Rick Thoman, who added that he hasn’t seen near-freezing temperatures at the North Pole at this time of year during his 30 years on the job. “There is a wow-factor.” As the warm air came in, the temperature popped up but it is expected to cool off and return to normal.

The unusual air temperatures above the Arctic sea ice are unlikely to have any impact on sea ice. “It has been below freezing for months, and there would be no melting because of the lack of sun,” said Thoman.

Mark Serreze, the director of the National Snow and Ice Data Center, part of the University of Colorado, Boulder, which monitors changes to Arctic sea ice extent and thickness, confirmed that Arctic sea ice would not be affected by the warm spell.

“It’s a short-lasting event. It’s not going to have a big effect on the sea ice cover,” he said. “There are strong winds associated with the weather pattern – and that could break things up – but I don’t see this one having a big effect.”

Air temperatures were as much as 25C (45F) above average over the Kara Sea, a portion of the Arctic Ocean adjacent to northwestern Russia, and 11C (19.8F) above average over Greenland, according to Jason Box, a glaciologist at the Geological Survey of Denmark and Greenland.

Greenland contains enormous volumes of ice that would raise sea levels by as much as six meters (18 feet) it were to melt entirely. No one expects that to happen any time soon, but ice continues to melt and fall into the ocean at an increasing rate. The length of the melt season on the western, northwestern and northeastern regions of the Greenland ice sheet were 30-40 days longer than average in 2015. Other locations showed average or below average melt seasons.

Warmer winter temperatures in Greenland can have an impact on the melt season that follows, but the fleeting nature of this weather event would probably not have an impact on Greenland’s glaciers, said Box.

Balmy weather a challenge for reindeer

Meanwhile temperatures soared to a new December record of 8.7C (47.7F) in Svalbard, Norway, a group of islands located in the Arctic Ocean, about midway between Europe and the North Pole. During the mid-winter months, temperatures usually average -16C (3.2F). The Norwegian Met Office forecasts that temperatures could stay close to freezing until the weekend.

Mild spells and rain do occur on Svalbard during the winter because of its location in the Arctic Ocean and the Gulf stream. “But the magnitude and frequency of this weather phenomenon in the last few years have been far from normal,” said Brage Hansen, a population ecologist at the Centre for Biodiversity Dynamics at the Norwegian University of Science and Technology. “Projections based on IPCC’s Global Circulation Models suggest that the frequency and magnitude of these types of events will continue to increase throughout the century,” he said.

The rain-on-snow events that often accompany the warmer weather can have serious impacts on the health of reindeer populations in the region. The ice layer blocks access to food plants throughout the winter, until May or June.

“The reindeer lose more weight and body fat than normal, more animals starve to death, and few of the females are able to keep their fetuses,” said Hansen. “These icing events sometimes lead to population crashes.”

The winter rain has negative impacts on other herbivores, such as voles and ptarmigan.

It can also cause slush avalanches. An extreme event in early 2012 wiped out a pedestrian bridge, closed the airports and roads for days, said Hansen. A snow avalanche buried houses in Longyearbyen on Svalbard in mid-December, killing two people.

Svalbard is also known for its polar bears. Scientists believe roughly 2,500 polar bears make up the Barents Sea population that live between Norway and Russia. According to the Norwegian Ice Service, sea ice in the region is at its third-lowest on record for this day.

“It’s an incredibly low sea ice year,” said Andrew Derocher, a polar bear biologist at the University of Alberta, in Edmonton. “Most of the areas that have traditionally been used for denning are probably unreachable.”

Derocher, who has studied polar bears in Svalbard, said the warm winter weather may not affect polar bears, even though the females tend to give birth close to the new year.

“I’d be more concerned if it were coming through in the spring, when the ring seals are pupping,” said Derocher. The seals give birth in snow caves, which can collapse following rain-on-snow events, and constrict the ring seal population, which polar bears depend on for food.

None of the scientists Arctic Deeply spoke with would attribute this particular event to climate change. “Too many people are too quick to attribute any extreme event to climate change. These extreme events do happen,” said Serreze. “It is probably related to the strong El Niño that you’ve got going on right now. It creates havoc in the weather patterns in the northern hemisphere,” he said, adding that further analysis was required.

“There are all kinds of interesting climate events to latch onto these days,” said Box. “But what we need to figure out is which ones really are unprecedented.”

Top image: Ground ice leads to high mortality among wild reindeer in Svalbard because it blocks access to the plants they eat for food. (Pixabay/Enra)