There it goes again…Polar Vortex is a term many of us in North America have heard quite frequently this year from news reporters and weather forecasters trying to justify the harsh winter conditions many of us are still experiencing. So what is it and why is it to blame?
For those of you who are interested, here is the cliff notes version. The Polar Vortex is a mass of cold circulating air hovering over both the North and South Poles. In the north for example the vortex is normally centered over Baffin Island and North Eastern Siberia. Primarily a low pressure system, the strength of the vortex and its ability to migrate (bringing frigid temperatures with it) depends on the temperature difference between the equator and the poles.
What allowed the polar vortex to shift so far south this winter was a series of events that started in late December. An Arctic cold front carried by a strong nor’easter triggered a large dump of snow blanketing northern Canada and cooling everything down. The large amount of descending cold air colliding with the rising warm southern air caused high winds and lower temperatures adding to the cooling. This temperature shift pushed the jet stream farther south allowing for the cold arctic air carried by the polar vortex to creep in. This deep freeze caused record ice cover over the Great Lakes and record low temperatures over much of North America as the region experienced bouts of severe winter weather. In total over 200 million people were affected as the polar vortex extended from the Rocky Mountains to the Atlantic Ocean.
Was this a freak weather phenomenon or are we looking at experiencing more events like this in the future? It’s hard to say. What scientists have determined is that there is a direct correlation between decreased ice cover over the North Atlantic and a weak polar vortex the proceeding winter. This is due to an increase in the ocean’s overall water temperature –Earth’s temperature/climate mediator.