As titled. How does the hole fell specifically on that region of the stratosphere above the Antarctic and why?
Mostly temperature, leakage of CFCs(Chlorofluorocarbons), produced for early model refrigeration units thinned the ozone layer a bit all over the world but in Antarctica, and to a lesser extent over Scandinavia, CFCs were frozen into winter snowfall rather than effecting the ozone layer equally year round. Small amounts of ozone damage regenerated reasonably quickly, I understand the reaction is self catalysing but I'm not sure of that, but the flood of CFCs evaporating with the summer thaw in colder climates overwhelmed the natural increase and thus the massive hole down south. The Arctic isn't as badly effected due to the combination of fact that much of the melting ice turns to water which absorbs much of the CFC burden, continental Antarctica sees more ablation in summer months than melting, and the fact that global air currents concentrated much of the pollutant matter south of the equator in the first place.