STRATOSPHERIC OZONE: GENRATION AND LOSS. ozone forms when oxygen molecules(O2) are dissociated by ultraviolet radiation and the resulting oxygen combine with other oxygen molecules:
Chlorine atoms from chlorofluorocarbon compounds released into the atmosphere play a central role in one of the most efficient ozone-destroying catalytic cycles in the stratosphere. The cycle begins with the breakup of an ozone molecule by atomic chlorine and the formation of chlorine monoxide(CIO) and molecular oxygen: