The Polar Vortex is a large area of low pressure and cold air that permanently surrounds the Earth’s North and South Poles. While it is often discussed as a single “weather event” when it causes cold snaps, it is actually a constant atmospheric feature that becomes stronger in the winter and weaker in the summer.
There are actually two distinct polar vortices in our atmosphere: one in the troposphere (where we live and where weather occurs) and one in the stratosphere (much higher up).