Rate of Formation of the ClO Dimer in the Polar Stratosphere: Implications for Ozone Loss

• Published in: Science
• Main Authors: Sander, Stanley P., Friedl, Randall R., Yung, Yuk L.
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Association for the Advancement of Science (AAAS) 1989
• Subjects: Multidisciplinary; Antarctic; The Antarctic; Antarc*
• Online Access: http://dx.doi.org/10.1126/science.245.4922.1095; https://www.science.org/doi/pdf/10.1126/science.245.4922.1095

The gas-phase recombination of chlorine monoxide (ClO) has been investigated under the conditions of pressure and temperature that prevail in the Antarctic stratosphere during the period of maximum ozone (O 3 ) disappearance. Measured rate constants are less than one-half as great as the previously accepted values. One-dimensional model calculations based on the new rate data indicate that currently accepted chemical mechanisms can quantitatively account for the observed O 3 losses in late spring (17 September to 7 October). A qualitative assessment indicates that the existing mechanisms can only account for at most one-half of the measured O 3 depletion in the early spring (28 August to 17 September), indicating that there may be additional catalytic cycles, besides those currently recognized, that destroy O 3 .