It seems scientists do have a sense of humour.
But it is a dark one.
“We called it Santa’s revenge,” said Jennifer Francis, chuckling to herself.
Few others are laughing about this winter’s weather.
Santa’s revenge is the name Francis, along with four other panel members at last week’s conference of the American Association for the Advancement of Science, placed on their theory of the causes of this winter’s wacky weather.
And you’re going to find it hard to believe.
It’s global warming. Or, rather, it stems from the Arctic warming faster than the rest of the planet.
“This is causing the jet stream to take on a wavier path as it travels around the Northern Hemisphere,” said Francis, a research professor at Rutgers University in New Jersey, in a telephone interview Tuesday.
“Those waves create the weather we feel on the surface.”
The jet stream is kind of like a fast-moving river of air about 1,000 metres above us. While there is more than one jet stream, the one that’s made for all our shovelling this winter is the polar jet. It’s relatively narrow — a few hundred kilometres wide — and it takes huge zigzags north and south as the band of wind makes its way east.
The winds of the polar jet have been clocked as high as 398 kilometres an hour, but typically they’re a good deal slower.
The jet stream is fuelled by the spinning of the Earth on its axis and the difference in temperature between the Arctic and mid-latitudes. When there’s less of a temperature difference, it takes a more meandering course like a slow-moving river.
This year, it has headed south along the Rocky Mountains all the way to Georgia before turning north and passing south of Nova Scotia on its way to bringing miserable weather to Britain. Georgia’s also been plagued by snow and ice storms this winter.
The jet stream is not bad to everybody. It depends which side you’re on.
“On one side of the jet stream, you tend to have a rising motion in the air, where moisture rising creates clouds and storms,” Francis said.
“On the other side, you’ll tend to have a descending motion, causing it to be drier.”
The crux is that when the jet stream takes on a long, slow course, as it has this winter, areas tend to get stuck with prolonged periods of either clear and dry or miserable weather, Francis said.
“So the West Coast has all been dry, Alaska is warm, Scandinavia is very warm and so is Sochi (Russia).”
Next year, Nova Scotia may end up on a different side of the jet stream and get all the nice weather, Francis said.
Perhaps then it could be called Nova Scotia’s revenge.