New ozone hole found above the Arctic

A small ozone hole has been detected above the Arctic, covering less than 1 million square kilometers, compared to the larger Antarctic hole. The European Space Agency (ESA) attributes this to strong westerly winds from the polar vortex trapping cold air over the North Pole. When the polar winter ended, sunlight triggered ozone depletion, forming this unusual mini hole. This Arctic ozone hole formation differs from the Antarctic one, which occurs annually due to cold temperatures and human pollution.

What triggers the depletion of ozone in the Arctic during the polar winter?

What are the main differences between the formation of the Arctic and Antarctic ozone holes?