Earlier this month, a sudden atmospheric warming event caused the Arctic’s polar vortex to reverse its trajectory. The swirling ring of cold air is now spinning in the wrong direction, which has triggered a record-breaking “ozone spike” and could impact global weather patterns.
The polar vortex circling the Arctic is swirling in the wrong direction after surprise warming in the upper atmosphere triggered a major reversal event earlier this month. It is one of the most extreme atmospheric U-turns seen in recent memory.
In the past, disruptions to the polar vortex — a rotating mass of cold air that circles the Arctic — have triggered extremely cold weather and storms across large parts of the U.S..
The current change in the vortex’s direction probably won’t lead to a similar “big freeze.” But the sudden switch-up has caused a record-breaking “ozone spike” above the North Pole.
The polar vortex is most prominent during winter months and extends into the stratosphere — the second layer of the atmosphere up to around 30 miles (50 kilometers) above the surface. The vortex spins counterclockwise with wind speeds of around 155 mph (250 km/h), which is around the same speed as a Category 5 hurricane, according to the U.K. Met Office. A similar vortex also encircles Antarctica during the southern winter.