Arctic Continues to Run a Fever
December 24, 2016
A modest proposal.
When weather casters show that big map of North America with weather systems moving across it, at the end of the spot, the view should pull back, and show temperatures not only in North America, but across the globe, in relation to historical averages – like the image above from the U of Maine’s Climate re-analyzer.
Every day, just so folks who do not follow such stuff would gradually get it.
The Arctic continues to run a fever.
On Thursday, the temperature there was almost 30 C warmer than average, and it continued into Friday morning. Ocean buoys recorded temperatures near the North Pole of 0 C or warmer. That’s right: It’s warmer in the Arctic than it is in Thunder Bay, Ont.
This isn’t an isolated event. Arctic temperatures have been unusually warm for the past few months, though perhaps not quite as dramatically different as we’re seeing now.
In November, the region was 20 C warmer than average.
“The temperatures there of the atmosphere are on … any given day, like 20 C warmer than they should be for this time of year,” Jennifer Francis, a marine and coastal sciences research professor at Rutgers University in New Jersey, told CBC News at the time.
“The ocean temperatures there are also warmer than they should be. I’m really, really worried, and I think everyone should be.”
The core idea here begins with the fact that the Arctic is warming up faster than the mid-latitudes and the equator, and losing its characteristic floating sea ice cover in the process. This also changes the Arctic atmosphere, the theory goes, and these changes interact with large scale atmospheric patterns that affect our weather (phenomena like the jet stream and the polar vortex). We won’t get into the details yet, but in essence, the result can be a kind of swapping of the cold air masses of the Arctic with the warm air masses to the south of them. The Arctic then gets hot (relatively), and the mid-latitudes — including sometimes, as during the infamous “polar vortex” event of 2013-2014, the United States — get cold.
Here’s an animation, (Above) provided by Jason Box of the Geological Survey of Denmark and Greenland, of what this might look like. It shows that both during the November major Arctic warming event, and again this week, temperatures over the Arctic ocean spiked far above their average, while temperatures over some high or mid-latitude land surfaces in the Northern Hemisphere fell well below average (the Arctic is at the far right):
Dr Friederike Otto, a senior researcher at Oxford’s Environmental Change Institute told BBC News that in pre-industrial times “a heatwave like this would have been extremely rare – we would expect it to occur about every 1,000 years”.
Dr Otto added that scientists are “very confident” that the weather patterns were linked to anthropogenic climate change.
“We have used several different climate modelling approaches and observations,” she told BBC News.
“And in all our methods, we find the same thing; we cannot model a heatwave like this without the anthropogenic signal.”
Temperatures are forecast to peak on Christmas Eve around the North Pole – at near-freezing.
The warm air from the North Atlantic is forecast to flow all the way to the North Pole via Spitsbergen, giving rise to clouds that prevent heat from escaping.
And, as Dr Otto explained to BBC News, the reduction in sea ice is contributing to this “feedback loop”.
“If the globe is warming, then the sea ice and ice on land [shrinks] then the darker water and land is exposed,” she said.
“Then the sunlight is absorbed rather than reflected as it would be by the ice.
David Phillips, senior climatologist with Environment and Climate Change Canada , said that instead of the air flow moving west to east, as it typically does, patterns are changing. Now there is more of a north-south interaction where warm air moves up from the south. However, the northern air can also dip further down, as we saw the past two weeks with unusually cold temperatures across the country. The change in air flow can cause the wild swings we are seeing more often.
In this case, warm air over Greenland and Norway is being pulled up to the Arctic, causing the unusual weather.
There was a similar event last winter, said Jim Overland, an oceanographer with the National Oceanic and Atmospheric Administration (NOAA). At the time they thought it was just a strange occurrence, but with a second one in just a year, it’s left them wondering if this is what they can expect more often.
As for how long this will last, it’s anyone’s guess.
“It’s not inconceivable that it could last another couple of months or the chaos that exists will wipe out the pattern in a week or so. We don’t know which one. We think, though, long-term t