Advances in Geosciences www.adv-geosci.net 1680-7340 1680-7359 16 Observation, Prediction and Verification of Precipitation (EGU Session 2007) 2008 10.5194/adgeo-16-43-2008 http://www.adv-geosci.net/16/43/2008/ http://www.adv-geosci.net/16/43/2008/adgeo-16-43-2008.html http://www.adv-geosci.net/16/43/2008/adgeo-16-43-2008.pdf 43 48 2008-04-09 Certified accuracy of rainfall data as a standard requirement in scientific investigations L. G. Lanza luca.lanza@unige.it L. Stagi Department of Construction, Environmental and Territorial Engineering, University of Genoa, Italy This paper elaborates on the rationale behind the proposed standard limits for the accuracy of rainfall intensity measurements obtained from tipping-bucket and other types of rain gauges. Indeed, based on experimental results obtained in the course of international instrument Intercomparison initiatives and specific laboratory tests, it is shown here that the accuracy of operational rain gauges can be reduced to the limits of ±1% after proper calibration and correction. This figure is proposed as a standard accuracy requirement for the use of rain data in scientific investigations. This limit is also proposed as the reference accuracy for operational rain gauge networks in order to comply with quality assurance systems in meteorological observations. Adami, A. and Da Deppo, L.: On the systematic errors of tipping bucket recording rain gauges. Proc. Int. Workshop on the Correction of Precipitation Measurements, Zurich, 1–3~April~1985. Calder, I. R. and Kidd, C. H. R.: A note on the dynamic calibration of tipping-bucket gauges, J. Hydrology, 39, 383–386, 1978. CIMO-XIII: Commission for Instruments and Methods of Observation, Thirteenth Session, Final Report, Bratislava, 25~September–3~October~2002, WMO Rep No 947 (available at http://www.wmo.int/pages/prog/www/IMOP/reports.html), 2002. La Barbera, P., Lanza, L. G., and Stagi, L.: Influence of systematic mechanical errors of tipping-bucket rain gauges on the statistics of rainfall extremes, Water Sci. Techn., 45(2), 1–9, 2002. Lanza, L. G., Leroy, M., Alexadropoulos, C., Stagi, L., and Wauben, W.: WMO Laboratory Intercomparison of Rainfall Intensity Gauges – Final Report, IOM Report No 84, WMO/TD No 1304, 2005. Marsalek J.: Calibration of the tipping bucket raingage J. Hydrology, 53, 343–354, 1981. Maksimovi\'c, \`E., Bužek, L., and Petrovi\'c, J.: Corrections of rainfall data obtained by tipping bucket rain gauge, Atmospheric Research, 27, 45–53, 1991. Molini, A., La Barbera, P., Lanza, L. G., Stagi, L.: Rainfall intermittency and the sampling error of tipping-bucket rain gauges, Phys. Chem. Earth (C), 26(10–12), 737–742, 2001. Molini, A., Lanza, L. G., and La Barbera, P.: The impact of tipping-bucket raingauge measurement errors on design rainfall for urban-scale applications, Hydrol. Proc., 19, 1073–1088, 2005a. Molini, A., Lanza, L. G., and La Barbera, P.: Improving the uncertainty of rain intensity records by disaggregation techniques Atmos. Res., 77, 203–217, 2005b. Niemczynowicz J.: The dynamic calibration of tipping-bucket raingauges, Nordic Hydrology, 17, 203–214, 1986. WMO: Guide to Meteorological Instruments and Methods of Observation, WMO-No 8, 7th ed., World Meteorological Organization, Geneva, Switzerland, 2006.