The depletion of ozone layer occurs over Antarctica during spring time and it gets replenished after spring time. Explain.

Explanation

It is because sun begins to shine over Antarctica during spring, HOCI and Cl are photolyzed by sunlight.
`HOCl (g) + hv ("sunlight") to overset(*)OH + overset(*)Cl`
`Cl_2 (g) + hv ("sunlight") to 2overset(*)Cl (g)`
The reactive chlorine atoms deplete ozone layer. During winter polar stratospheric clouds are formed, stable wind pattern encircle the continent. It is so rigid that it isolates the air from sun. After the spring, intensity of sunlight increases. This decreases the wind pattern and ozone rich air rushes in and replenishes the ozone hole.