Polar Vortex Prophet

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Jennifer Francis’ long relationship with the extremes and vagaries of arctic weather began on a sailboat. In 1985, during a long break from college, she and her future husband completed a five-year sailing adventure that took them to places like Cape Horn, deep in New Zealand and, ultimately, over the Arctic Circle.

“At the time, we were told that we had gone further north than any other American sailboat,” says Francis. The couple’s biggest challenge – more than lacking modern equipment like GPS or mobile phones – was that the further north they went, the less reliable the weather forecasts became.

“The weather really controls your life when you live on a sailboat,” says Francis. And accurate information on the weather in the Arctic was sorely lacking.

Francis resolved to fill this gap. Today, as senior scientist to Woodwell Climate Research Center in Falmouth, Massachusetts, she is one of the world’s foremost experts on the polar vortex. This phenomenon is at least vaguely familiar to any American who witnessed last year’s winter storm Uri, which killed hundreds of people in Texas and caused more than 4 million households losing electricity during a severe thunderstorm.

Francis describes the polar vortex as a “spinning top” of cold air that normally hovers over the Arctic, but occasionally breaks up into several mini-tops of frigid air that descend over North America, from Europe and Asia.

Almost exactly one year ago, in February 2021, the polar vortex separated for most of winter and the United States witnessed the weather chaos that can ensue. At this time, an offshoot descended on North America as far as Texas. Temperatures have plunged there 40 degrees Fahrenheit below par and news reports posed the increasingly common question: was it climate change?

Francis has appeared in deep freeze news stories time and time again, largely because she was one of the first scientists to link more frequent disturbances of polar vortices to climate change. About 10 years ago, she began studying how the rapid warming of the Arctic could have a ripple effect on lower latitudes. While Francis says it’s too early to know if climate change played a direct role in last February’s freeze, she suspects global warming will increasingly disrupt the polar vortex and send intense cold snaps toward South.

“Other things can also disrupt the polar vortex, but it’s a very hot area of ​​research,” she says, adding that the Texas storm is “consistent with the kinds of things we expect to see happening. more often”.

Francis had no intention of becoming a climatologist, although growing up in a small sailing town on the Massachusetts coast gave him an early love for the weather. At school, she wanted to study dentistry, but changed her mind after sailing around the world. When Francis returned to dry land, she changed majors and joined the meteorology department at San José State University, which had a treasure trove of Arctic data. It wasn’t until Francis went on to graduate school at the University of Washington that she linked this research to climate change.

Like his world tour, Francis’ research pushes the boundaries. To date, she has been researching climate change in the Arctic for almost 30 years, but her breakout moment came in 2012. That year, Francis and Stephen Vavrusan atmospheric scientist at the University of Wisconsin, published a paper suggesting a link between Arctic warming and severe winter storms further south.

The Arctic is warming twice as fast like the rest of the planet. According to Francis and Vavrus, this reduced temperature difference between the Arctic and lower latitudes caused the jet stream, a band of west-to-east winds in the northern hemisphere, to slow down and become “undulating” – a meandering river. rather than a fast, straight channel. Usually, the jet stream maintains the polar vortex in the Arctic, but these waves in its circulation allow frigid air from the north to plunge south into warmer latitudes.

Upon publication, their research landed on the New York Times cover page. It was a “hairpin turn” in his career, Francis says. “From that moment, I became a science communicator.”

In 2014, a severe polar vortex event in the eastern United States drew more attention to their work, as well as criticism from other researchers. Several eminent climatologists have written in Science that while Francis and Vavrus’ article offered “an interesting idea”, it lacked supporting evidence.

Francis and Vavrus are the first to say that their 2012 paper represented preliminary results. They floated the idea before they had solid evidence, Vavrus says, and hoped the idea would spark further research. They did not expect their work to receive so much media coverage at such an early stage.

“I was never satisfied with this order,” he says. “Probably, neither does Jennifer.”

One of the authors of the warning Science letter, John Walsh, chief scientist of the University of Alaska’s International Center for Arctic Research, says they did not rule out a link between Arctic warming and extreme mid-latitude weather. Rather, they wanted to point out other potential factors.

Before, says Walsh, the “party line in climate science” was that the tropics were responsible for everything that happened at mid-latitudes. “That started to change when Jennifer and Steve Vavrus started posting articles suggesting the Arctic might play a role,” he says. “I think Jennifer deserves a lot of credit for coming up with the idea.”

Judah Cohendirector of the company’s seasonal forecast Atmospheric and environmental research, accept. He recently led a study review current research on Arctic warming and mid-latitude weather patterns. (Francis and Vavrus were among the co-authors.) He discovered that there were still two camps: one saying that the Arctic significantly influences extreme winter weather, and the other saying that this n is not the case, at least not very much.

Cohen concluded that one of the reasons this divide persists is that the computer models that many researchers use to describe the interactions between different parts of the climate do not agree with the latest Arctic temperature measurements. He also says these models should incorporate more research into how the stratosphere – the second layer of the atmosphere located about 11 km above the ground and home to the polar vortex – interacts with the lower troposphere, where our daily weather conditions.

It’s one of the topics Francis is studying these days as she thinks about new ways to measure and categorize different types of polar vortex disturbances.

Along the way, she communicates this complex science to the public. Since her now famous 2012 article, Francis has been quoted in numerous news stories and testified at three congressional hearings on climate change. Despite the ongoing controversy over her own research, Francis is encouraged by the growing acceptance of climate science as a whole, both by the general public and by politicians.

She thinks winter storms like the one in Texas boost public acceptance. “Climate change directly affects people through these various types of extreme weather events,” she says.

The rapid warming of the Arctic is also affecting everyone indirectly, through melting glaciers and rising sea levels, as well as additional carbon dioxide and methane escaping into the atmosphere at due to melting permafrost. But extreme weather — the kind that freezes an entire state’s power grid — is much more personal.

“By connecting to people’s lives,” says Francis, “we gained ground in helping to make climate change a more tangible concept.”

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