Effects of Cosmic Rays on Atmospheric Chlorofluorocarbon Dissociation and Ozone Depletion

Data from satellite, balloon, and ground-station measurements show that ozone loss is strongly correlated with cosmic-ray ionization-rate variations with altitude, latitude, and time. Moreover, our laboratory data indicate that the dissociation induced by cosmic rays for ${\mathrm{CF}}_2{\mathrm{Cl}}_2$ and ${\mathrm{CFCl}}_3$ on ice surfaces in the polar stratosphere at an altitude of $\sim 15\mathrm{km}$ is quite efficient, with estimated rates of $4.3\times {10}^{-5\mathrm{}}$ and $3.6\times {10}^{-4\mathrm{}}{\mathrm{s}}^{-1\mathrm{}}$, respectively. These findings suggest that dissociation of chlorofluorocarbons by capture of electrons produced by cosmic rays and localized in polar stratospheric cloud ice may play a significant role in causing the ozone hole.