ACCURACY OF STRATOSPHERIC TEMPERATURE IN ANALYSES OF GLOBAL METEOROLOGICAL MODELS FROM COMPARISONS TO LONG DURATION BALLOON MEASUREMENTS

摘要

The temperature of the stratosphere has been measured in the Arctic vortex along the trajectory of Infra Red Montgolfier (MIR) long duration balloons flown for 7 to 22 days during the winters of 1997, 1999 and 2000. The performances of global meteorological analyses, ECMWF 31 and 50 levels, UKMO, DAO, NCEP and NCEP/NCAR reanalysis are investigated by comparison to this large and homogeneous experimental data set. Most of the analyses, except ECMWF31 in 1999, do show a small average warm bias of between 0 and 1.6 K. The average scatter between analyses and measurements varied from +-1.0 to +-3.0 K depending on the model and the year. The newly available ECMWF 50 levels version assimilating the high vertical resolution radiance of the space borne Advanced Microwave Sounding Unit, performs significantly better (0.03 +- 1.12 K on average between 10 and 140 hPa in 1999 and 2000) than other analyses.