Accuracy of tretyakov precipitation gauge: Result of wmo intercomparison

Abstract

The Tretyakov non-recording precipitation gauge has been used historically as the official precipitation measurement instrument in the Russian (formerly the USSR) climatic and hydrological station network and in a number of other European countries. From 1986 to 1993, the accuracy and performance of this gauge were evaluated during the WMO Solid Precipitation Measurement Intercomparison at 11 stations in Canada, the USA, Russia, Germany, Finland, Romania and Croatia. The double fence intercomparison reference (DFIR) was the reference standard used at all the Intercomparison stations in the Intercomparison. The Intercomparison data collected at the different sites are compatible with respect to the catch ratio (measured/DFIR) for the same gauge, when compared using mean wind speed at the height of the gauge orifice during the observation period.The Intercomparison data for the Tretyakov gauge were compiled from measurements made at these WMO intercomparison sites. These data represent a variety of climates, terrains and exposures. The effects of environmental factors, such as wind speed, wind direction, type of precipitation and temperature, on gauge catch ratios were investigated. Wind speed was found to be the most important factor determining the gauge catch and air temperature had a secondary effect when precipitation was classified into snow, mixed and rain. The results of the analysis of gauge catch ratio versus wind speed and temperature on a daily time step are presented for various types of precipitation. Independent checks of the correction equations against the DFIR have been conducted at those Intercomparison stations and a good agreement (difference less than 10%) has been obtained. The use of such adjustment procedures should significantly improve the accuracy and homogeneity of gauge-measured precipitation data over large regions of the former USSR and central Europe.

Bias correction of daily precipitation measurements for Greenland

“…When wind speed is not measured at the height of the gauge, it was estimated from measurements at higher heights, using the logarithmic wind profile approach. It has been well documented that for the same wind speed gauge, undercatch for snow is much higher than for rain [Goodison et al, 1981;Yang et al, 1995Yang et al, , 1998b. Classifying the type of precipitation is therefore necessary in order to apply the best wind-loss correction.…”

An evaluation of the Wyoming Gauge System for snowfall measurement

“…The WMO Solid Precipitation Measurement Intercomparison Project has developed improved bias correction techniques for a number of precipitation gauges commonly used around the world ], such as the Canadian Nipher snow gauge [Goodison and Metcalfe, 1992], the United States National Weather Service (NWS) 8-inch standard gauge [Yang et al, 1998b], the Russian Tretyakov gauge [Yang et al, 1995], and the Hellmann gauges [Gunther, 1993; Allerup et al, 1997; Yang et al, 1999b]. Application of the WMO bias correction methods to the national precipitation data has resulted in significantly higher estimates of precipitation particularly in the high-latitude regions [Metcalfe et al, 1994;Yang et al, 1998aYang et al, , 1999aYang, 1999].…”

“…Gauge catch of precipitation depends on both the environmental factors and the precipitation features and can vary for each precipitation event Yang et al, 1995Yang et al, , 1998bYang et al, , 1999b. It is therefore desirable, if not essential, to examine the compatibility of Wyoming shielded gauge and DFIR records on a shorter timescale.…”

Quantification of precipitation measurement discontinuity induced by wind shields on national gauges

“…Corrections for these biases are therefore necessary for all types of gauge measurements. Biascorrection methods have been recently developed from the WMO Intercomparison Project for many national gauges Yang et al, 1995Yang et al, , 1998a, and they are recommended to be implemented to current and archived national records so as to produce the unbiased (true) precipitation data over large regions Yang and Goodison, 1998]. …”