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| Titel |
Snow-sourced bromine and its implications for polar tropospheric ozone |
| VerfasserIn |
X. Yang, J. A. Pyle, R. A. Cox, N. Theys, M. Roozendael |
| 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 ; 10, no. 16 ; Nr. 10, no. 16 (2010-08-24), S.7763-7773 |
| Datensatznummer |
250008719
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| Publikation (Nr.) |
 copernicus.org/acp-10-7763-2010.pdf |
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| Zusammenfassung |
| In the last two decades, significant depletion of boundary layer ozone
(ozone depletion events, ODEs) has been observed in both Arctic and
Antarctic spring. ODEs are attributed to catalytic destruction by bromine
radicals (Br plus BrO), especially during bromine explosion events (BEs),
when high concentrations of BrO periodically occur. However, neither the
exact source of bromine nor the mechanism for sustaining the observed high
BrO concentrations is completely understood. Here, by considering the
production of sea salt aerosol from snow lying on sea ice during blowing
snow events and the subsequent release of bromine, we successfully simulate
the BEs using a global chemistry transport model. We find that heterogeneous
reactions play an important role in sustaining a high fraction of the total
inorganic bromine as BrO. We also find that emissions of bromine associated
with blowing snow contribute significantly to BrO at mid-latitudes. Modeled
tropospheric BrO columns generally compare well with the tropospheric BrO
columns retrieved from the GOME satellite instrument (Global Ozone
Monitoring Experiment). The additional blowing snow bromine source,
identified here, reduces modeled high latitude lower tropospheric ozone
amounts by up to an average 8% in polar spring. |
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