What is the Polar Vortex? How does it work?
The winter of 2013/2014 was bitterly cold across much of North America. In fact, according to Environment Canada it was the coldest Canadian winter in 18 years, and third coldest in 35 years. Nationally, the five months from November to March were Canada’s coldest since record-keeping began in 1948.
Needless to say, cold records were handily broken in many communities, and many cities issued vastly more cold weather alerts than in the previous winters.
Economically the cold, along with strong snowfalls and an ice storm, played havoc with power grids and infrastructure, and plants’ “winterkill” rates were higher than normal.
So was the polar vortex responsible? Oh yes. But the phenomenon wasn’t new by any means.
What is the Polar Vortex?
Simply, the Polar Vortex is a large area of cold air and low pressure that sprawls across Earth’s poles. The scary-sounding “vortex” monicker comes from the fact that it’s cyclonic: It rotates (counter-clockwise in the Northern Hemisphere) in a flow of air that keeps cooler air near the poles.
It’s also fairly high up in the lower/middle stratosphere, but its effects stretch down into the upper part of the troposphere, the first layer of Earth’s atmosphere where our planet’s weather takes place.
The polar vortex is really dependent on large-scale temperature variations in Earth’s atmosphere between the poles and the equator as the year progresses. As such, the polar vortex is confined to polar latitudes in summertime, but “dips” in the winter as the northern hemisphere’s average temperatures drop, bringing colder air southward.
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