The chilling temperatures across this United States this winter, which have brought record inches of snow and cold temperatures, all stem from the polar vortex. But what exactly is the polar vortex?

A polar vortex, while sounding like it is right out of a science-fiction movie, is simply a point of low pressure that causes the upward blowing of chilly air to equalize the pressure in the environment. This causes the “feels like” temperature disparities known as wind chills. “Feels like” is a term used by NSIS’s heat index, and refers to the apparent temperature felt by people as a whole. These wind chills are behind the highly negative “feels like” temperatures in the Windy City, Chicago. Even when the low on January 31 this year was negative 22 degrees Fahrenheit, the wind chills put the “feels like” temperature at negative 55 degrees.

These wind chills massively influence the actual temperatures because the polar vortex swirls from above the global poles, which can surge to the south and trigger the extreme temperatures in the cold, passing through Canada, America, Europe, and Siberia. While we only hear about these during the affected winters, the polar vortexes actually never cease.

The stability of the polar vortexes, as they circle around the poles, with cold congregating in the Arctic or Antarctic, are often impeded by the Arctic change–namely, the melting of the polar ice caps. The sea ice melting is hypothesized to be what weakens the polar vortexes, causing them to spill cold air into North America and Europe. While some use this influx of cold weather to posit that global warming could never be a legitimate concern, the common occurrence of the polar vortexes’ powers are only indicative of the prevalence of climate change and how immediate action needs to be taken in order to preserve our planet.