The forces that brought record-high winter temperatures to the Arctic are creating conditions that are ripe for a new record-low sea ice extent later this year, one Alaska scientist warned on Friday.
This year's pattern of low winter sea ice and weather is "quite similar" to the winter pattern that led to what was a record-low sea ice extent in September 2007, said Xiangdong Zhang with the International Arctic Research Center at the University of Alaska Fairbanks.
"We already got the increased temperature this winter, so what may happen for sea ice this summer?" Zhang said in a briefing at the Arctic Science Summit Week held at UAF. "If the pattern continues similar to what happened in 2007, we may get another record-low sea-ice cover."
Zhang cited new findings from his work and that of his research partners into the particulars that have led to this winter's record-warm Arctic conditions, which he said "made a strong contribution" to the record-warm global conditions in the December-to-February period.
"We tried to understand what caused this dramatic increase of temperature in just one season," he said. "We looked at the weather pattern, we looked at the atmospheric circulation pattern."
They found that a single superstorm that hit in December caused air temperatures in the central Arctic to shoot up by 7 degrees Celsius (12.6 degrees Fahrenheit), he said. "Just one storm increased surface temperature in the center of the Arctic for 7 degrees."
They also found, through analysis of seasonal mean sea-level pressure, a powerful pattern of atmospheric flow northward from the Atlantic, he said.
"There is a strong wind blowing from the North Atlantic into (the) Arctic that transports moisture, that transports heat into the Arctic," he said.
And the current scarcity of winter sea ice in the Barents and Kara seas is a repeat of conditions from the winter of 2006-07, he said.
Such low ice conditions in winter in the Barents and Kara seas also emerged in 2005, which later became the record-low sea ice year at the time, and in 2003, which was also considered a low-ice year by the standards of that time. Since then, however, the nine lowest sea-ice minimum extents in the satellite record have all been in 2007 and the ensuing years, according to the National Snow and Ice Data Center.
Correction: An earlier version of this article incorrectly converted the increase in Arctic air temperatures caused by a December storm. The storm drove up those temperatures by 12.6 degrees Fahrenheit, not 44.6 degrees.