Bias correction of global daily rain gauge measurements

Up to the present global precipitation climatologies based on rain gauges h ave been corrected for systematic measurement errors using monthly correcti on factors only. We present results from a statistical correction model for daily measurements. It was developed in the framework of BALTEX and adapte d for the Global Precipitation Climatology Centre (GPCC) to correct global daily rain gauge data routinely transmitted via GTS. We focus on regions of the GEWEX continental scale experimets BALTEX (Europe), GAME (Asia), LBA ( South-America) and GCIP (North-America). The correction model was applied t o 2 years of data (1996, 1997) and compared with the correction factors of the widely used precipitation climatology of Legates (1987). In the BALTEX region our averaged daily correction factor is about equal to the monthly c orrection given by Legates during the summer months, while Legates estimate d higher corrections for snow (up to 50 %). In the regions of GAME: and LBA the corrections given by Legates are also generally higher (50 - 100 %) th an our corrections. This is opposite to the corrections calculated for GCIP rain gauges, which are not significantly different. (C) 2001 Elsevier Scie nce Ltd. All rights reserved.