What is special about the South Pole versus the North Pole that leads to ozone depletion only at the south Pole?

Question

Quizplus · Accepted Answer

Polar stratospheric clouds, also known as "nacreous" clouds, form at high altitudes in the polar stratosphere during the winter months. These clouds provide a surface for chemical reactions involving chlorine and other substances, leading to the breakdown of ozone. These clouds are more common and persistent over the South Pole than the North Pole, leading to ozone depletion primarily at the South Pole.

What Is Special About the South Pole Versus the North