Polar vortex

The polar vortex is a persistent, large-scale cyclone located near the Earth's poles, in the middle and upper troposphere and the stratosphere. The vortex is most powerful in the hemisphere's winter, when the temperature gradient is steepest, and diminishes or can disappear in the summer. The Antarctic polar vortex is more pronounced and persistent than the Arctic one. The Arctic vortex is elongated in shape, with two centres, one roughly over Baffin Island in Canada and the other over northeast Siberia.

The chemistry of the Antarctic polar vortex has created severe ozone depletion. The nitric acid in polar stratospheric clouds reacts with CFCs to form chlorine, which destroys ozone. These clouds can only form at temperatures below about -80°C, so the warmer Arctic region does not have an ozone hole.

Other astronomical bodies are also known to have polar vortices, including Mars, Jupiter, and Saturn's moon Titan.

Sources

"Polar vortex". European Environment Agency multilingual environmental glossary. January 29. {{cite web}}: Check date values in: |date= and |year= / |date= mismatch (help) "Polar vortex". Glossary of Meteorology. January 29. {{cite web}}: Check date values in: |date= and |year= / |date= mismatch (help) "World temperature gradient". Integrated Publishing: Aerographer/Meteorology. January 29. {{cite web}}: Check date values in: |date= and |year= / |date= mismatch (help) "What is the polar vortex?". The Weather Prediction.com. January 29. {{cite web}}: Check date values in: |date= and |year= / |date= mismatch (help) "The Antarctic Polar Vortex". Dynamics in the Ocean and Atmosphere. January 29. {{cite web}}: Check date values in: |date= and |year= / |date= mismatch (help) "The Polar Vortex and Arctic Weather Patterns". Arctic Climatology and Meteorology. January 29. {{cite web}}: Check date values in: |date= and |year= / |date= mismatch (help)