Title Radiosonde stratospheric temperatures at Dumont d'Urville (Antarctica); trends and link with polar stratospheric clouds
Author David, C.; Keckhut, P.; Armetta, A.; Jumelet, J.; Snels, M.; Marchand, M.; Bekki, S.
Author Affil David, C., USVQ-UPMC-ParisVI- Institute Pierre-Simon Laplace, LATMOS, Paris, France. Other: CNR, Istituto di Scienze dell'Atmosfera e del Clima, Italy
Source Atmospheric Chemistry and Physics, 10(8), p.3813-3825. Publisher: Copernicus, Katlenburg-Lindau, International. ISSN: 1680- 7316
Publication Date 2010
Notes In English. Published in Atmospheric Chemistry and Physics Discussions: 1 December 2009, http://www.atmos-chem-phys- discuss.net/9/25687/2009/acpd-9-25687- 2009.html ; accessed in May, 2011. 64 refs. GeoRef Acc. No: 310056. CRREL Acc. No: 65006796
Index Terms atmospheric pressure; climatic change; clouds (meteorology); polar stratospheric clouds; cooling; humidity; lasers; lidar; ozone; polar regions; radar; remote sensing; stratosphere; temperature; Antarctica; polar regions; annual variations; climate change; clouds; Dumont d'Urville Station; laser methods; lidar methods; radar methods
Abstract Temperature profiles measurements are performed daily (00:00 UT) in Dumont d'Urville (6640'S, 14001'E) by Meteo- 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.
URL http://www.atmos-chem-phys.net/10/3813/2010/acp-10-3813-2010.pdf
Publication Type journal article
Record ID 91467