Bias correction for precipitation mesuament in Tanggula Mountain Tibetan Plateau

This paper presents the results of bias corrections for Geonor T-200B Pluviometer and Chinese standard precipitation gauge(CSPG)measurements in the middle of Tanggula Mountain,Tibetan Plateau.The precipitation observation in frigid mountainous areas is always the bottleneck for studies of regional hydrology and climate.During May-December 2005,a continuous meteorological measurement was conducted in the Dongkemadi glacial drainage.In the meantime,we take up a comparative analysis of the precipitation observation between ability of Geonor T-200B Pluviometer and CSPG.Based on the correlative relationship between precipitation type and temperature,the precipitation type can be divided by using the observed contemporary temperature 2.7℃ in the mountainous areas,therefore,the observed precipitation values are corrected.The bias corrections results show that the corrected precipitation value(662.1mm)of T-200B Pluviometer is closer to the corrected value(657.2 mm)of CSPG.The precipitation in 2005 compared with that of 1993 increases by 200 mm because of the bias corrections.Therefore,this study has great importance for reducing precipitation observation error in the frigid mountainous areas.