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| Titel |
The potential impact of ClOx radical complexes on polar stratospheric ozone loss processes |
| VerfasserIn |
B. Vogel, W. Feng, M. Streibel, R. Müller |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 6, no. 10 ; Nr. 6, no. 10 (2006-07-25), S.3099-3114 |
| Datensatznummer |
250004019
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| Publikation (Nr.) |
 copernicus.org/acp-6-3099-2006.pdf |
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| Zusammenfassung |
| The importance of radical-molecule complexes for atmospheric
chemistry has been discussed in recent years. In particular, the
existence of a ClO·O2 and ClOx water radical
complexes like ClO·H2O, OClO·H2O,
OClO·(H2O)2, and ClOO·H2O could play a role in
enhancing the ClO dimer (Cl2O2) formation and therefore may
constitute an important intermediate in polar stratospheric ozone loss
cycles. Model simulations performed with the Chemical Lagrangian Model
of the Stratosphere (CLaMS) will be presented to study the role of
radical complexes on polar stratospheric ozone loss processes. The
model simulations are performed for the Arctic winter 2002/2003 at a
level of 500 K potential temperature and the results are compared to
observed ozone loss rates determined by the Match technique. Moreover,
recently reported values for the equilibrium constant of the ClO dimer
formation are used to restrict the number of possible model results
caused by large uncertainties about radical complex chemistry. Our
model simulations show that the potential impact of ClO·O2 on
polar ozone loss processes is small (dO3/dt≪0.5 ppb/sunlight
h) provided that the ClO·O2 complex is only weakly
stable. Assuming that the binding energies of the ClOx water
complexes are much higher than theoretically predicted an enhancement
of the ozone loss rate by up to ≈0.5 ppb/sunlight h is
simulated. Because it is unlikely that the ClOx water
complexes are much more stable than predicted we conclude that these
complexes have no impact on polar stratospheric ozone loss
processes. Although large uncertainties about radical complex
chemistry exist, our findings show that the potential impact of
ClOx radical molecule complexes on polar stratospheric ozone
loss processes is very small considering pure gas-phase
chemistry. However the existence of ClOx radical-molecule
complexes could possibly explain discrepancies for the equilibrium
constant of the ClO dimer formation found between recent laboratory
and stratospheric measurements. |
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