Nor’easters. Blizzards. Arctic outbreaks. The dreaded polar vortex. Winter’s arsenal of misery is on its way, ready or not.
And against this backdrop of winter’s imminent arrival comes a new study that says unusual heat in the Arctic – caused by global warming – is bringing more of the fierce winter weather we loathe here in the US.
Specifically, the study finds that abnormally warm temperatures in the Arctic are associated with cold-air outbreaks and heavy snowfall here in North America.
“When the Arctic atmosphere is warmer than normal, we see a much higher likelihood of extreme winter weather across much of Canada, the northern U.S. and northern Eurasia,” said study lead author Judah Cohen of Atmospheric and Environmental Research, in an e-mail to USA TODAY. “The relationship is especially strong in the northeastern sections of the continents,” he said.
Arctic warming at world’s fastest rate
“In recent decades, the warming in the Arctic has been much faster than in the rest of the world, a phenomenon known as Arctic amplification,” a recent study said. Numerous other studies report that the Arctic is warming either twice, more than twice, or even three or four times as fast as the globe, on average.
This faster pace of warming is often attributed to the melting of sea ice, according to the World Wildlife Fund. As sea ice disappears, it is replaced by a growing expanse of dark ocean water that absorbs sunlight rather than reflecting it.
How does Arctic warmth affect our weather?
“Recent studies have theorized that rapid Arctic warming, a pace three-to-four times faster than the globe as a whole, may increase the likelihood of extreme weather events owing to a reduced north/south temperature difference,” said study co-author Jennifer Francis of the Woodwell Climate Research Center. “Slower westerly winds of the jet stream lead to more frequent convoluted jet-stream configurations, which lead to unusual weather.”
“Disruptions in the typically stable stratospheric polar vortex may also occur more often in a warming climate,” noted Cohen, “and we know hazardous winter weather is more likely during these disruptions.”
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Yes, we’ll still have winter
“Even though we’re seeing cold records being broken less often as the globe warms, we’ll still see debilitating spells of severe winter weather,” added Francis, in an e-mail. “There will be plenty of ice, snow, and frigid air in the Arctic winter for decades to come, and that cold can be displaced southward into heavily populated regions during Arctic heat waves.”
According to the Woodwell Climate Research Center, recent disruptive extreme winter weather events – such as the deadly Texas cold spell of February 2021 – have occurred and will continue to occur in the future, wreaking havoc on infrastructure, human wellbeing, and ecosystems, especially in areas unaccustomed to and ill-equipped for dealing with winter extremes.
What is the polar vortex?
The polar vortex is a gigantic circular upper-air weather pattern in the Arctic that envelops the North Pole. It’s a normal, natural pattern that is stronger in the winter and tends to keep the coldest weather bottled up near the North Pole. The jet stream usually pens the polar vortex in and keeps it there, but at times, some of the vortex can break off or move south, bringing extremely cold weather down into the U.S., Europe and Asia.
Some scientists, including Francis, say there could be a connection between global warming and the wandering polar vortex: The theory is that when weird warmth invades the Arctic, some of the cold that’s supposed to stay up there – including the vortex – sloshes down south into North America and Europe.
Michael Mann, a University of Pennsylvania meteorologist who was not involved in the study, praised the research, saying in an email to USA TODAY, “I think it’s a credible study that adds to the weight of evidence that amplified Arctic warming may be impacting the behavior of the jet stream and leading to more extreme weather.”
Arctic affects billions
“The Arctic may seem irrelevant and far away to most folks, but our findings say the profound changes there are affecting billions of people around the Northern Hemisphere,” added Francis. “To reverse these trends, it will take bold and rapid actions to reduce our burning of fossil fuels and the build-up of heat-trapping gasses in the atmosphere, but the tools exist if we can muster the will.”
The new study, “Anomalous Arctic warming linked with severe winter weather in Northern Hemisphere continents,” was published earlier this month in the peer-reviewed journal Nature Communications Earth and Environment.
This article originally appeared on USA TODAY: Global warming worsens winter weather here in the US, study suggests
