Mid-winter lower stratosphere temperatures in the Antarctic vortex: comparison between observations and ECMWF and NCEP operational models

摘要

Radiosonde temperature profiles from Belgrano (78° S) and otherAntarctic stations have been compared with European Centre for Medium-RangeWeather Forecasting (ECMWF) and National Centers for EnvironmentalPrediction (NCEP) operational analyses during the winter of 2003. Resultsshow good agreement between radiosondes and NCEP and a bias in the ECMWFmodel which is height and temperature dependent, being up to 3°C toocold at 80 and 25–30 hPa, and hence resulting in an overestimation of thepredicted potential PSC areas. Here we show the results of the comparisonand discuss the potential implications that this bias might have on theozone depletion computed by Chemical Transport Models based on ECMWFtemperature fields, after rejecting the possibility of a bias in the sondesat extreme low temperatures.