青藏高原唐古拉山区降水观测误差修正分析

青藏高原由于降水观测点分布等原因一直是水文和气候研究的薄弱环节。2005年5~10月在青藏高原唐古拉山中部冬克玛底河流域进行连续的人工气象观测。观测期间根据不同降水类型和气温之间的相关关系,采用气温2.7℃为临界值对降水类型进行了划分,利用已有的T-200B型自动雨雪量计和普通雨量计的修正公式,并在日尺度基础上对降水进行了修正对比。经过修正,中游T-200B型雨量站全年降水量662.1 mm;普通雨量计全年降水量为657.2 mm;2005年修正后的降水量相比1993年观测到的降水量472 mm增加了近200 mm。结果表明在高寒山区降水观测,依据同步观测的气温划分降水类型,可以根据相关修正公式修正T-200B型自动雨雪量计和普通雨量计降水观测值。从而能够在高寒山区恶劣的自然环境自动连续准确的观测高寒区域的降水。

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.