Edwin L. Aguirre
With winter just around the corner and the cost of natural gas, heating oil and electricity showing no sign of abating, many New Englanders are wondering if this season is going to be colder or snowier than in previous years.
Surprisingly, the answer might come not from our northern neighbor, Canada, but from a vast, sparsely populated region halfway around the world: Siberia.
A new ongoing study by Asst. Prof. Mathew Barlow of the Environmental, Earth and Atmospheric Sciences Department and his co-researchers proposes that increased snowfall in Siberia can actually lead to colder winter temperatures in the Northeast; less Siberian snow means a warmer winter for us.
“Our project is motivated by two ideas,” says Barlow. “First, decreasing Arctic sea ice appears to actually increase autumn snow over Siberia. Second, the amount of autumn snow cover over Siberia appears to play a role in influencing ― via a fairly complicated dynamical pathway ― subsequent winter winds over much of the Northern Hemisphere, including the United States.”
The project, which started in September, is funded through a $175,000 grant from the National Science Foundation.
“It’s a multi-institution project,” says Barlow. “I’m the principal investigator at UMass Lowell; Jessie Cherry is the PI at the University of Alaska Fairbanks and Judah Cohen at AER Inc. is the lead PI for the whole project. The $175,000 is just UMass Lowell’s part of the pie.”
Barlow adds that while decreasing Arctic sea ice has received a lot of media attention in terms of its local impact ߞ; that is, on the polar bear population ߞ; it will likely have hemisphere-wide impacts.
“We’re investigating one of those possible impacts in this study,” he says.
Another interesting angle the team is pursuing is the recent apparent slowing of global warming.
“It turns out that this is due mainly to Northern Hemisphere winter, which has actually gotten slightly colder over the last decade while the other three seasons have continued their merry warming ways,” he says.
Barlow says several possibilities have been suggested as to why winter has not been following the warming trend recently, but he and his colleagues have published a paper that shows a link between recent winter cooling and snow over Siberia. That paper, co-authored with Cohen and Kazuyuki Saito of the Japan Agency for Marine-Earth Science and Technology and entitled “Decadal Fluctuations in Planetary Wave Forcing Modulate Global Warming in Late Boreal Winter,” appeared in the Aug. 15 Journal of Climate.
“We argue that the positive trend in [Siberian] snow cover has contributed a significant fraction of the observed cooling in eastern North America and northern Eurasia, where snow cover is significantly correlated with winter temperatures,” they wrote.