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| Titel |
Will climate change increase ozone depletion from low-energy-electron precipitation? |
| VerfasserIn |
A. J. G. Baumgaertner, P. Jöckel, M. Dameris, P. J. Crutzen  |
| 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. 19 ; Nr. 10, no. 19 (2010-10-11), S.9647-9656 |
| Datensatznummer |
250008824
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| Publikation (Nr.) |
 copernicus.org/acp-10-9647-2010.pdf |
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| Zusammenfassung |
| We investigate the effects of a strengthened stratospheric/mesospheric residual circulation on the
transport of nitric oxide (NO) produced by energetic particle precipitation.
During periods of high geomagnetic activity, energetic electron
precipitation (EEP) is responsible for winter time ozone loss in the polar middle
atmosphere between 1 and 6 hPa. However, as climate change is expected to
increase the strength of the Brewer-Dobson circulation including extratropical downwelling, the enhancements of
EEP NOx concentrations are expected to be transported to lower altitudes
in extratropical regions, becoming more significant in the ozone
budget. Changes in the mesospheric residual circulation are also
considered. We use simulations with the chemistry climate model system
EMAC to compare present day effects of EEP NOx
with expected effects in a climate change scenario for the year
2100. In years of strong geomagnetic activity, similar to that observed in
2003, an additional polar ozone loss of up to 0.4 μmol/mol at
5 hPa is found in the Southern Hemisphere. However, this would be approximately compensated by an ozone
enhancement originating from a stronger poleward transport of ozone from
lower latitudes caused by a strengthened Brewer-Dobson circulation, as well
as by slower photochemical ozone loss reactions in a stratosphere cooled by
risen greenhouse gas concentrations. In the Northern Hemisphere the EEP NOx
effect appears to lose importance due to the different nature of the climate-change induced circulation changes. |
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