A polar vortex (kyokūzu/極渦) is a persistent, large-scale cyclone located near either of a planet's geographical poles. The extreme arctic blasts that wreaked havoc across the United States last week were caused by a counterclockwise-rotating pool of cold, dense air. The frigid air, piled up at the North Pole, was pushed south, making it as far as the Gulf Coast.
19 mins ago
With your current subscription plan you can comment on stories. However, before writing your first comment, please create a display name in the Profile section of your subscriber account page.