POLARVORTEX
Polar vortex
A polar vortex is a persistent, large-scale cyclone located near one or both of a planet's geographical poles. On Earth, the polar vortices are located in the middle and upper troposphere and the stratosphere. They surround the polar highs and lie in the wake of the polar front. These cold-core low-pressure areas strengthen in the winter and weaken in the summer. They usually span 1,000–2,000 kilometers in which the air is circulating in a counter-clockwise fashion . The reason for the rotation is the same as any other cyclone, the Coriolis effect.The above text is a snippet from Wikipedia: Polar vortex
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