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| Titel |
Halogens and their role in polar boundary-layer ozone depletion |
| VerfasserIn |
W. R. Simpson, R. Glasow, K. Riedel, P. Anderson, P. Ariya, J. Bottenheim, J. Burrows, L. J. Carpenter, U. Frieß, M. E. Goodsite, D. Heard, M. Hutterli, H.-W. Jacobi, L. Kaleschke, B. Neff, J. Plane, U. Platt, A. Richter, H. Roscoe, R. Sander, P. Shepson, J. Sodeau, A. Steffen, T. Wagner, E. Wolff |
| 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 ; 7, no. 16 ; Nr. 7, no. 16 (2007-08-22), S.4375-4418 |
| Datensatznummer |
250005174
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| Publikation (Nr.) |
 copernicus.org/acp-7-4375-2007.pdf |
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| Zusammenfassung |
| During springtime in the polar regions, unique photochemistry
converts inert halide salt ions (e.g. Br−) into reactive halogen
species (e.g. Br atoms and BrO) that deplete ozone in the boundary
layer to near zero levels. Since their discovery in the late 1980s,
research on ozone depletion events (ODEs) has made great advances;
however many key processes remain poorly understood. In this article
we review the history, chemistry, dependence on environmental
conditions, and impacts of ODEs. This research has shown the
central role of bromine photochemistry, but how salts are
transported from the ocean and are oxidized to become reactive
halogen species in the air is still not fully understood. Halogens
other than bromine (chlorine and iodine) are also activated through
incompletely understood mechanisms that are probably coupled to
bromine chemistry. The main consequence of halogen activation is
chemical destruction of ozone, which removes the primary precursor
of atmospheric oxidation, and generation of reactive halogen
atoms/oxides that become the primary oxidizing species. The
different reactivity of halogens as compared to OH and ozone has
broad impacts on atmospheric chemistry, including near complete
removal and deposition of mercury, alteration of oxidation fates for
organic gases, and export of bromine into the free troposphere.
Recent changes in the climate of the Arctic and state of the Arctic
sea ice cover are likely to have strong effects on halogen
activation and ODEs; however, more research is needed to make
meaningful predictions of these changes. |
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