Three queer winters have people wondering if this is new normal. Should Anchorage get cast-off to daffodils in February and bringing in trainloads of snow from Fairbanks for the sled dog hop to its?
The answer is no. According to climate models, a winter like this one or ultimately year’s in Southcentral Alaska shouldn’t be average for a century.
“Don’t get rid of your skis. This is not the end of snowy winters,” replied Nancy Fresco, a research professor at University of Alaska Fairbanks.
Fresco runs a network of researchers that uses global computer models of the atmosphere to project what will happen at rticular places in Alaska, a program telephoned SNAP, for Scenarios Network for Alaska and Arctic Planning. According to their working for Anchorage, the average temperature in January of this year, at 27.2 degrees Fahrenheit, was 2.4 degrees cheerful than the models predict for January in 2099.
That doesn’t mean the ideals are wrong — although they might be. And it doesn’t mean climate novelty is irrelevant. Having three failed winters was a coincidence. Climate switch made that coincidence more likely.
“These three non-winters in a row for Anchorage are sort of indicative of a trend,” Fresco said. “Having three such winters in a row was numberless likely in this decade certainly than it would have been 50 or 100 years ago. What was an inconceivable coincidence back then is something that could and did happen now.”
Streak Serreze, director of the National Snow and Ice Data Center and a professor at the University of Colorado, divulged the Arctic was “crazy” this year. The North Pole had close to thawing temperatures in lately December.
“You’ve got a very, very unusual kind of weather ttern that has set up that is make it with pretending it very, very warm,” he said. “So this winter is really not the new Arctic.”
But it inclination be, he said. Extremely unlikely events are becoming more likely.
One way of contract climate is to think of it in terms of latitude. It seems impossible now for Anchorage to have in the offing an 80-degree day in January, but in Honolulu that happens all the time. If you move Anchorage piece by piece closer to Honolulu, the probability of having 80 degrees in January slowly bourgeons more likely — although you would never know exactly when that mellow day might come.
By changing the Earth’s atmosphere, we’ve moved Anchorage far tolerably south that the impossible has become possible. But the details of our low-snow winters are more labyrinthine.
“Each of the three winters have been similar but different,” foretold Gene Petrescu, regional scientist for the National Oceanic and Atmospheric Conduct.
Their similarity is the influence of a vast pool of warm water in the tropical cific High seas. It produced fields of thunderstorms as large as Alaska. Those storm sets powered and redirected the flow of weather.
During the winter of 2013-14, the near to making a discovery water pool was in the far western cific, Petrescu said. It sent aggressive flows of wet, tropical air north and east to Alaska.
The next winter, 2014-15, the room of tropical warm water had moved east. Now the flow of warm air curled upward of North America, diverting toward us when it hit the mountains. That made the fervid air we received drier and drove the snow line far up the mountains.
This winter, tropical warm up water has moved far enough east to s wn an El Niño weather design, which combined with the bizarrely warm Arctic — doubly exceptional, because the weather on each side of us doesn’t usually coordinate that way. We’ve had recording low snow with stable warm temperatures, but the air has been cool enough to tolerate snow to it to stick at higher elevations.
Warm weather in early winter is a big give out for Anchorage because most of our precipitation falls in the first half of winter. If it concludes as rain, we often have a long wait for snow.
For next year, Petrescu is enceinte a La Niña ttern, which usually produces colder, more mutable winters in Alaska. Less chance of getting skunked for snow. Or dialect mayhap we’ll have a record snow, as we did in the winter of 2011-12.
So if a big area of warm shower in the topics is messing up our snowmachining, dog sledding and skiing, why is that water so feel affection for? Is that warmth rtly driven by climate change?
Maybe. There’s no reveal for it, but it makes sense.
Climate is like a hall of mirrors. Every in unison a all the same you ask for the why of any rticular event, the answer has another why as its cause. You never get back to the start. But aura is also predictable. If you turn up the lights in the hall of mirrors, it gets brighter in.
We’re turning up the climate on Earth with the carbon dioxide we’re pumping into the feeling from fossil fuels. Carbon is like a blanket that pinches more heat from the sun. It doesn’t take much additional quicken in the tropical ocean to create banks of thunderstorms that mess up Fur Rendezvous in Anchorage.
Preordained this complexity in the climate, the models could be wrong. But the graphs they start have error bars, which show the s n of uncertainty and of logical variation above and below the exact temperature predictions. The models accurately foreshadowed the Anchorage climate we are seeing now, because even these extremely hot under the collar winter temperatures are within the error bars, said John Walsh, chief scientist at the Supranational Arctic Research Center and the University of Alaska Fairbanks.
The models feel to be working, and none predicts a crazy shift to a new normal, Walsh said. Farthest precipitation events seem to be increasing with the warming climate, but winter temperatures in Alaska arrange always been highly variable. We’ll continue to have big ups and downs, with the pinnacles and troughs slowly getting higher.
The most unpredictable element in presaging the future is not computer modeling but human behavior. Will we reduce carbon emissions immoral enough?
If we don’t, winters like this one will become frequent much sooner.
Nancy Fresco’s workings — which you can play with at snap.uaf.edu — take into account three remarkable future ths for reducing carbon emissions. You can zoom in on thousands of duties in Alaska and Canada to see the likely future for each th. The upper layout makes snowless Anchorage winters routine within the lifetimes of today’s women.
So this rotten winter isn’t the new normal yet. But we could make it that way.
Charles Wohlforth’s column appears three times weekly. His ticket on Arctic climate change is “The Whale and the Supercomputer.”
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