ACP Atmospheric Chemistry and Physics ACP 1680-7324 Copernicus GmbH Göttingen, Germany 10.5194/acp-7-435-2007 Mid-winter lower stratosphere temperatures in the Antarctic vortex: comparison between observations and ECMWF and NCEP operational models Parrondo M. C. 1 Yela M. 1 Gil M. 1 von der Gathen P. 2 Ochoa H. 3 Instituto Nacional de Técnica Aeroespacial, Torrejón de Ardoz, Spain Alfred Wegener Institute for Polar and Marine Research, Research Unit Potsdam, Germany Dirección Nacional de Antártico, Buenos Aires, Argentina 24 01 2007 7 2 435 441 This is an open-access article ditributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. This article is available from http://www.atmos-chem-phys.net/7/435/2007/acp-7-435-2007.html The full text article is available as a PDF file from http://www.atmos-chem-phys.net/7/435/2007/acp-7-435-2007.pdf

Radiosonde temperature profiles from Belgrano (78° S) and other Antarctic stations have been compared with European Centre for Medium-Range Weather Forecasting (ECMWF) and National Centers for Environmental Prediction (NCEP) operational analyses during the winter of 2003. Results show good agreement between radiosondes and NCEP and a bias in the ECMWF model which is height and temperature dependent, being up to 3°C too cold at 80 and 25–30 hPa, and hence resulting in an overestimation of the predicted potential PSC areas. Here we show the results of the comparison and discuss the potential implications that this bias might have on the ozone depletion computed by Chemical Transport Models based on ECMWF temperature fields, after rejecting the possibility of a bias in the sondes at extreme low temperatures.

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