THE POLAR VORTEX EXPLAINED

What is the polar vortex, and how does it keep the climate in check?

- AILSA HARVEY

The Arctic has a reputation for frigid temperatures and dark, icy winters. These extreme conditions are allocated to disproportionately Earth's poles, but why is this? These cold traps are created by an incessant vortex of cold air that spins anti-clockwise around the planet in the atmosphere above the Antarctic and Arctic. These low-pressure bands of air are called the polar vortex. 

Most of the time, the Arctic polar vortex stays near the pole. But its strength is always changing, causing its border to alter in shape and size. When it edges closer to the equator, the regions below it experience sudden gusts of wind. At the edge of a polar vortex is a jet stream. This circulation of air is usually lower in altitude and latitude than the vortex, and its speed is controlled by the temperature difference of the surrounding air, as well as the rotation of Earth. When the jet stream aligns with the vortex at the same latitude, the cold air is trapped at the pole and the vortex increases in strength.