This station has the longest record of ozone levels. Go the following address, which shows the amount of ozone over North America each March from 1984 - 1997. Go to the following address to view similar data for the South Pole, from 1979 - 1996. Compare the amount of change seen in ultraviolet radiation at the South Pole with North America. The ozone depletion process begins when CFCs and other ozone-depleting substances leak from equipment.
Winds efficiently mix the troposphere and evenly distribute the gases.
CFCs are extremely stable, and they do not dissolve in rain. After a period of several years, ozone-depleting substances reach the stratosphere. Strong UV light breaks apart the ozone-depleting substance molecule. CFCs release chlorine atoms, and halons release bromine atoms . It is these atoms that actually destroy ozone, not the intact ozone-depleting substance molecule.