"explain how the antarctic ozone hole is caused mainly by catalytic destruction of ozone by chlorine"

When humans improperly dispose of  equipment like refrigerators than have CFC and HCFCs, when they are subjected to UV light from the sun, they decompose to release Cl- radicals (CFCl3  CFCl2+ + Cl-). When the CL- are released into the atmosphere, they reach the stratosphere and react with the ozone. The Ozone is reduced from O3 to O2;

Cl + O3 -- ClO + O2

ClO + O - Cl + O2

the answer to you question is   jet streams