Atmos. Chem. Phys. Discuss., 9, 25687-25722, 2009
© Author(s) 2009. This work is distributed
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This discussion paper has been under review for the journal Atmospheric Chemistry and Physics (ACP). Please refer to the corresponding final paper in ACP.
Radiosondes stratospheric temperatures from 1957 to 2008 at Dumont d'Urville (Antarctica): trends and link with Polar Stratospheric Clouds
C. David1,2, P. Keckhut1, A. Armetta1, J. Jumelet1, M. Marchand1, and S. Bekki1
1LATMOS-IPSL, UVSQ, Univ. UPMC Paris 6, 4 place Jussieu, Paris, France
2Institut Polaire Français Paul-Emile Victor (IPEV), Plouzané, France

Abstract. Temperature profiles measurements are performed daily (00:00 UT) in Dumont d'Urville by Météo-France, using standard radiosondes, since the International Geophysical Year in 1957. A significant cooling of about 2.3 K/decade at 20 km appears between 1957 and 2008, consistent with other Antarctic studies. Due to a 16 years data gap between 1963 and 1978, 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 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. 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.

Citation: David, C., Keckhut, P., Armetta, A., Jumelet, J., Marchand, M., and Bekki, S.: Radiosondes stratospheric temperatures from 1957 to 2008 at Dumont d'Urville (Antarctica): trends and link with Polar Stratospheric Clouds, Atmos. Chem. Phys. Discuss., 9, 25687-25722, doi:10.5194/acpd-9-25687-2009, 2009.
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