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| Titel |
Why unprecedented ozone loss in the Arctic in 2011? Is it related to climate change? |
| VerfasserIn |
J.-P. Pommereau, F. Goutail, F. Lefèvre, A. Pazmino, C. Adams, V. Dorokhov, P. Eriksen, R. Kivi, K. Stebel, X. Zhao, 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 ; 13, no. 10 ; Nr. 13, no. 10 (2013-05-27), S.5299-5308 |
| Datensatznummer |
250018672
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| Publikation (Nr.) |
 copernicus.org/acp-13-5299-2013.pdf |
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| Zusammenfassung |
An unprecedented ozone loss occurred in the Arctic in spring 2011. The
details of the event are revisited from the twice-daily total ozone and
NO2 column measurements of the eight SAOZ/NDACC (Système d'Analyse
par Observation Zénithale/Network for Detection of Atmospheric
Composition Changes) stations in the Arctic. It is shown that the total ozone
depletion in the polar vortex reached 38% (approx. 170 DU) by the end of
March, which is larger than the 30% of the previous record in 1996. Aside
from the long extension of the cold stratospheric NAT PSC period, the
amplitude of the event is shown to be resulting from a record daily total
ozone loss rate of 0.7% d−1 after mid-February, never seen before in
the Arctic but similar to that observed in the Antarctic over the last
20 yr. This high loss rate is attributed to the absence of NOx
in the vortex until the final warming, in contrast to all previous winters
where, as shown by the early increase of NO2 diurnal increase, partial
renoxification occurs by import of NOx or HNO3 from the
outside after minor warming episodes, leading to partial chlorine
deactivation.
The cause of the absence of renoxification and thus of high loss rate, is
attributed to a vortex strength similar to that of the Antarctic but never
seen before in the Arctic. The total ozone reduction on 20 March was
identical to that of the 2002 Antarctic winter, which ended around
20 September, and a 15-day extension of the cold period would have been
enough to reach the mean yearly amplitude of the Antarctic ozone hole.
However there is no sign of trend since 1994, either in PSC (polar
stratospheric cloud) volume (volume of air cold enough to allow formation of
PSCs), early winter denitrification, late vortex renoxification, and vortex
strength or in total ozone loss. The unprecedented large Arctic ozone loss in
2011 appears to result from an extreme meteorological event and there is no
indication of possible strengthening related to climate change. |
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