What is a polar vortex?

Polar vertex is a persistent, large-scale, upper-level low-pressure area, less than 1,000 kilometers in diameter, that rotates counter-clockwise at the North Pole and clockwise at the South Pole

A polar vortex is a persistent, large-scale, upper-level low-pressure area, less than 1,000 kilometers in diameter, that rotates counter-clockwise at the North Pole and clockwise at the South Pole, i.e., both polar vortices rotate eastward around the poles. The vortices weaken and strengthen from year to year

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