Highs in the lower 30 degrees (0 Celsius) are not very unusual in the summer, but they are far from the norm in the winter. The mild temperatures are also accompanied by liquid rains at the northernmost latitudes, accelerating the seasonal melting of the sea ice.
“Looking back over the past few decades, we can clearly see a warming trend, especially during the ‘cold season’ in the Arctic,” wrote Ruth Mottram, a climatologist at the Danish Meteorological Institute, in an e -mail. “It is not surprising that warm air is entering the Arctic this year. In general, we expect to see more and more of these events in the future.
Average temperatures in the High Arctic north of 80 degrees latitude are about 25 degrees (14 degrees Celsius) above normal. Some forecast models indicate that small areas of the Arctic, including near the North Pole, could experience temperatures up to 45 to 54 degrees (25 to 30 degrees Celsius) above normal on Wednesday and Thursday.
In Hopen, an island off Svalbard in the Barents Sea at 76 degrees north latitude, the temperature has recently reaches 39 degrees (3.9 Celsius)its highest March temperature on record.
Record-breaking ‘bomb cyclone’ drives heat north
Mottram linked the warm air intrusion to an atmospheric river—or concentrated jet of moisture—directed north by the bomb cyclone. A bomb cyclone is a storm or area of low pressure that intensifies at breakneck speed.
The cyclone formed along the east coast of the United States on Friday and Saturday, unleashing heavy snowfall and strong winds. Then, on Sunday and Monday, it crossed Atlantic Canada, where its pressure dropped to that found in the heart of Hurricane Sandy in 2012. Then it swept into Greenland.
“It appears that a new record has been set for the lowest pressure ever recorded in Greenland at 934.1 hPa measured at [Danish Meteorological Institute] station at Ikermiuarssuk,” Mottram said. The pressure reading has not been officially certified as a record, but Mottram notes that it is consistent with other observations and model predictions.
Mean atmospheric pressure at sea level is closer to 1000 hPa (hectoPascals); the resulting deficit was equivalent to removing 6.6% of the mass of the atmosphere from the middle of the storm – hence the strong inland winds aimed at “filling the void”. This resulted in a band of warm, moisture-rich air or an atmospheric river that meandered poleward.
The NOAA HySplit model, which calculates the paths the air took to reach its destination, reveals that the air mass carried north by the bomb cyclone rolled up east of Greenland and beyond. above Iceland during the weekend. Weather models indicate that the same heat plume will reach the North Pole on Wednesday with temperatures between 29 and 33 degrees (near 0 Celsius).
Researchers probe Arctic heat as sea ice levels hover at record highs
“This is exactly the situation we aim to cover with the ongoing 6-week campaign,” the team said in an emailed statement. “We’re trying to put together some of the puzzle pieces of the so-called ‘Arctic amplification’ (a stronger warming of the Arctic compared to [mean] global warming). And hot air intrusions are actually one of the candidates to explain this phenomenon.
The Arctic is warming three times faster than the rest of the planet, and atmospheric scientists are trying to better understand the processes contributing to such a rapid rise in temperatures.
So far, the team has observed a number of phenomena that display telling climate implications, many of which have been spurred by the sudden warming.
“For example, heavy rain on sea ice,” the team wrote. “This could have serious implications for a possible early melting of the sea ice in mid-March!”
The team also encountered large convective clouds, or clouds powered by vertical heat transfer in the atmosphere. Some had bloomed almost as high as the clouds usually found in the tropics.
“Surface temperatures in the Fram Strait are currently more than 20 degrees Celsius higher than predicted for long-term records,” the team continued. “It is not just the intensity of the current warm air intrusion, but also the duration, that appears unusual. Forecast products indicate that sea ice will be seriously disrupted by this massive warming event.”
According to the National Snow and Ice Data Center, the current extent of sea ice, defined as the area with at least 15% sea ice cover, scrapes the bottom of the barrel. Currently, it is on the verge of falling below the record low set in the summer of 2012, which could happen if current trends continue. About 14.6 million square kilometers are covered in ice, compared to an average of 15.5 million square kilometers in mid-March.
Arctic temperatures will drop to some degree by Thursday, but are expected to remain unusually mild through the next week.
The heat pulse over the Arctic is one of many that have swelled the region in recent decades. A 2017 study found that warm winter events in the Arctic are becoming more frequent and lasting longer. From 1980 to 2016, six additional warming events occurred per winter at the North Pole, lasting on average 12 hours longer, compared to the period from 1893 to 1979.
Jason Samenow contributed to this report.