Freakishly mild Arctic winter leads to lowest winter sea ice cover on record

Arctic sea ice hit its lowest annual maximum on record as of March 24, after one of the most unusually mild winters that many Arctic residents and longtime observers have ever seen. The sea ice maximum, according to the National Snow and Ice Data Center, was even lower than the record level seen just last year, according to the National Snow and Ice Data Center (NSIDC) in Boulder, Colorado. 

According to the NSIDC, the sea ice extent on March 24 was 5.607 million square miles, or 14.52 million square kilometers.

“I’ve never seen such a warm, crazy winter in the Arctic,” said NSIDC director Mark Serreze. “The heat was relentless.”  

Below-average ice conditions were seen everywhere except in the Labrador Sea, Baffin Bay, and Hudson Bay, the NSIDC found. 

To put the record low into perspective, consider that this was 431,000 square miles, or 1.12 million square kilometers below the 1981-2010 average of 6.04 million square miles, or 15.64 million square kilometers. That's about the size of the states of Texas, Arizona and Kansas combined. 

It was just below the level reached in 2015, by about 5,000 square miles, or 13,000 square kilometers. 

This year’s maximum occurred twelve days later than the 1981 to 2010 average date of March 12, although the date has varied dramatically throughout the satellite record. 

Original image has been replaced. Credit: Mashable

Sea ice extent was particularly low in the Barents Sea, north of Scandinavia, with large below average anomalies in the Kara Sea as well. 

According to the NSIDC, unusually mild air temperatures were the main factor that prevented the sea ice pack from expanding and locking in for the winter. Above average temperatures "plagued the Arctic all winter," the release said. 

The temperature anomalies this winter were simply staggering. Air temperatures in the lower atmosphere from December through February (the three meteorological winter months) were above average everywhere in the Arctic, with the largest anomalies near the North Pole and from the Kara Sea toward Svalbard, Norway. 

“I’ve never seen such a warm, crazy winter in the Arctic”

Some areas saw temperatures during the period average about 6 degrees Celsius, or 11 degrees Fahrenheit, above average. 

Similar anomalies were seen in the first two weeks of March from the North Pole toward northern Greenland. An absurdly large temperature anomaly was seen during this period near Svalbard, which is the northernmost settled area in the world, with temperatures there up to 12 degrees Celsius, or 22 degrees Fahrenheit, above average for the time of year. 

Original image has been replaced. Credit: Mashable

In recent years, numerous studies have been published that show rapid Arctic warming may be altering weather patterns far from the Arctic Circle, including potentially altering the jet stream winds that steer storms across the U.S. and Europe.

While this is still an active area of research, it's becoming clearer that whatever happens in the Arctic likely does not remain safely locked away in that region. 

The Arctic is in crisis.

“The Arctic is in crisis. Year by year, it’s slipping into a new state, and it’s hard to see how that won’t have an effect on weather throughout the Northern Hemisphere,” said Ted Scambos, NSIDC lead scientist, in a statement.

The air temperature at the North Pole even reached or possibly exceeded the freezing point at least twice during the January to February period as powerful ocean storms pulled mild air from the Atlantic northward into the high Arctic.

"These unusually warm conditions have no doubt played a role in the record low ice extent this winter," the NSIDC stated. 

Globally, January and February were the two most unusually warm months since instrument records began in the late 19th century. 

In addition to the temperatures, prevailing winds also contributed to the sea ice record, including southerly winds in the Kara and Barents seas that helped keep the ice edge north of its typical position. 

Original image has been replaced. Credit: Mashable

"This area has also seen an influx of warm Atlantic waters from the Norwegian Sea," NSIDC stated.

The record low sea ice maximum does not guarantee that sea ice will dwindle to a record low extent this summer, though. The summer melt season is also determined by prevailing weather patterns and when widespread sea ice surface melting commences. 

If melting begins relatively early in the melt season, then the snow and ice surface will darken and absorb more incoming solar radiation, thereby speeding up the melt. 

"With the likelihood that much of the Arctic cover is somewhat thinner due to the warm winter, early surface melting would favor reduced summer ice cover," the NSIDC stated.

In an illustration of feedback loops at work in the Arctic, the areas that had below average sea ice tended to be much milder and have more moisture in the air than areas that had a healthier amount of sea ice, the NSIDC found. This was the case near Svalbard, for example.

Global warming is driving Arctic sea ice into a steep decline, to the point where cruise lines are now selling tickets for voyages through the famed Northwest Passage, which had remained closed throughout recorded human history. 

“It is likely that we're going to keep seeing smaller wintertime maximums in the future because in addition to a warmer atmosphere, the ocean has also warmed up," said Walt Meier, an ice researcher with NASA, in a statement. "That warmer ocean will not let the ice edge expand as far south as it used to,” Meier said. 

Since the start of the satellite era in 1979, there has been a loss of 620,000 square miles of wintertime sea ice cover, which is about twice the size of Texas.