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 CF(2)Cl(2) and CFCl(3) on ice surfaces in the polar stratosphere at an altitude of approximately 15 km is quite efficient, with estimated rates of 4.3 x 10(-5) and 3.6 x 10(-4) s(-1), 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.
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Group of the Canadian Institutes of Health Research in Radiation Sciences, Faculty of Medicine, University of Sherbrooke, Sherbrooke, Canada, J1H 5N4.
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D000393:Air Pollutants / Q000737:chemistry*; D001272:Atmosphere; D017402:Chlorofluorocarbons / Q000737:chemistry*; D003359:Cosmic Radiation / Q000009:adverse effects*; D010126:Ozone / Q000737:chemistry*
D000393:Air Pollutants; D017402:Chlorofluorocarbons; D010126:Ozone