ACPD Atmospheric Chemistry and Physics Discussions ACPD 1680-7375 Copernicus GmbH Göttingen, Germany 10.5194/acpd-6-7697-2006 Mid-winter lower stratosphere temperatures in the Antarctic vortex: comparison between observations and ECMWF operational model. 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 09 08 2006 6 4 7697 7714 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-discuss.net/6/7697/2006/acpd-6-7697-2006.html The full text article is available as a PDF file from http://www.atmos-chem-phys-discuss.net/6/7697/2006/acpd-6-7697-2006.pdf

Radiosonde temperature profiles from Belgrano (78° S) and other Antarctic stations have been compared with European Centre for Medium-Range Weather Forecasts (ECMWF) data during the winter of 2003. Results show a bias in the operational model which is height and temperature dependent, being too cold at layers peaking 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 by considering the possibility of a bias in the sondes at extremely low temperatures and discuss the potential implications that this bias might have on the ozone depletion computed by Climate Transport Model based on ECMWF temperature fields.