Are the polar vortexes main cause of ozone hole?

Question

I read some articles and news from various sources that the Arctic ozone hole has recovered. Some people claim that less emission of harmful gases due to covid-19 made this happen. AFAIK, the past few decades regulating and banning emission of CFCs and other harmful gases should have contributed to this.

But Some articles says that polar vortexes contribute to the change of the Ozone layer. It is a fact that CFCs and other ozone-depleting gases react with the Ozone layer and damage it.

My question is for the arctic/antarctic Ozone holes, do polar vortexes contribute more?

PS: This article in the Sinhala language made me ask this question. If you like, translate and read.

Answer 1

To blame ozone destruction on the polar vortex would be like blaming trees for surface ozone production downwind of cities. Yes, nature is involved in the process, but nature is not the source of the catalytic pollutant that caused large change in ozone concentrations.

The polar vortex is a naturally occurring meteorological phenomena that has occurred for millions of years, and the ozone layer was fine. The issue is man-made halogenated compounds that catalytically destroy ozone (e.g. CFCs) when polar stratospheric clouds (PSCs) form. The stronger the polar vortex, the colder it is and the longer the PSCs stick around, allowing more destruction of ozone. The continental ice sheet over the south pole allows extremely cold temperatures, and so PSCs have been more prevalent there. Typically the Antarctic circle is much colder than the Arctic, so ozone destruction has been more prevalent in the southern hemisphere. However, polar stratospheric clouds are occurring with increasing frequency in the Arctic.

I suppose you could argue that if there were no polar vortices, the ozone layer would not be so susceptible to CFCs. However, the polar vortex and associated PSCs is a natural phenomena we cannot avoid.