Chicago waits out the "polar vortex." Photo: Flicker/akasped
By now you’re aware of the deadly cold that has spread across much of North America. (As I type it’s 8 degrees Fahrenheit outside my window. It was seven below zero a few nights ago. Much of the heartland has seen double-digit negatives.) This peculiar weather is not only inconvenient and uncomfortable for those with the means to stay warm, it is devastating for the homeless and for those who cannot afford to heat their homes.
One of several semi-permanent weather systems over the Earth, the polar vortex is an area of low pressure in the upper atmosphere, primarily in the stratosphere, the layer of the atmosphere above which most of our sensible weather occurs (known as the troposphere).
To emphasize, this vortex is semi-permanent. It is often in place near the poles. It is nothing new.
The Northern Hemisphere polar vortex frequently, but not always, has centers in two main areas: near Canada's Baffin Island, and over northeast Siberia. There is a Southern Hemispheric version of the polar vortex, as well, within which depletion of the upper-atmospheric ozone layer occurs.
The vortex is strongest in winter, thanks to an increased temperature contrast between the polar regions and the mid-latitudes, including the United States.
Occasionally, pieces of the larger spin can break off and sweep toward southern Canada, helping to rive Arctic cold plunges into the U.S.
In the case of this outbreak, the main circulation of the polar vortex in the stratosphere and upper reaches of the troposphere remained in place over northern Greenland and near Baffin Island. If you think of the vortex as a spinning wheel, one of its "spokes" did extend southward into the U.S. as January began.
Meanwhile, lower in the atmosphere at jet stream level, a pair of upper-level disturbances, one from the northeast Pacific Ocean and another rotating southward out of Canada's Northwest Territories, merged to help dig a sharp southward plunge in the jet stream, unleashing the Arctic blast into the nation's Midwest, South and East.
Well, in any event, temperatures will begin to moderate tomorrow as the polar vortex snaps back into shape. Winter will continue and spring will come. The cycles of nature will go on but they will go on differently over time.
The science is clear on this—even if some deny it.
But if we can't agree on the science, could we not agree, if on nothing else, on the need to pray for those in harms way of foul weather. This prayer (which I've modified slightly) seems appropriate given tomorrow's gospel reading.