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| Titel |
Radiosonde stratospheric temperatures at Dumont d'Urville (Antarctica): trends and link with polar stratospheric clouds |
| VerfasserIn |
C. David, P. Keckhut, A. Armetta, J. Jumelet, M. Snels, M. Marchand, S. Bekki |
| 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. 8 ; Nr. 10, no. 8 (2010-04-23), S.3813-3825 |
| Datensatznummer |
250008374
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| Publikation (Nr.) |
 copernicus.org/acp-10-3813-2010.pdf |
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| Zusammenfassung |
| Temperature profiles measurements are performed daily (00:00 UT) in Dumont
d'Urville (66°40' S, 140°01' E) by Météo-France, using
standard radiosondes, since the International Geophysical Year in 1957. Yet,
due to a 16 years data gap between 1963 and 1978, the entire dataset is only
used for a qualitative overview. Only the most recent series, between 1979
and 2008, is used to investigate the inter-annual stratospheric temperatures
variability. Over Dumont d'Urville, at the edge of the vortex, the annual
mean temperature cooling of about 1 K/decade at 20 km is the result of the
cooling trends between 0.5 and 1.4 K/decade, in summer and autumn and a
warming of about 1.1 K/decade in spring. These values are consistent with
values obtained using data from inner vortex stations, but with smaller
amplitude. No statistically significant trend is detected in winter. We
propose here the first attempt to link stratospheric temperature trends to
Polar Stratospheric Cloud (PSC) trends in Antarctica based on the only
continuous 20 years database of PSC lidar detection. Despite the absence of
mean temperature trend during winter, the occurrence of temperatures below
the NAT threshold between 1989 and 2008 reveals a significant trend of about
+6%/decade. The PSCs occurrences frequency exhibits a concomitant trend
of about +3%/decade, although not statistically significant. Yet, this
is consistent with results obtained in the Northern Hemisphere. Such a
possible positive trend in PSC occurrence has to be further explored to be
confirmed or invalidated. If confirmed, this PSC trend is likely to have
strong impacts, both on ozone recovery and climate evolution in Antarctica.
The study also reveals the importance of trends on extreme temperatures, and
not only on mean temperatures. |
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