Critically analyse the role of the polar vortex in influencing extreme mid-latitude weather events and stratospheric ozone depletion. How does its changing behaviour illustrate the links between weather variability and climate change? (Answer in 250 words)

The polar vortex is a large-scale cyclonic circulation of strong westerly winds around the poles in the upper troposphere and lower stratosphere, strongest in winter when the equator–pole temperature contrast is high. Its changing behaviour influences both extreme mid-latitude weather and stratospheric ozone chemistry.