The Effect of Dimensions and Shape of Precipitation Gauges on the Wind-Induced Error

The results of various kinds of studies into the physics of precipitation gauges including field intercomparison measurements, wind tunnel experiments and simulation using computational fluid dynamics are reviewed. The focus is on the effects of precipitation gauge construction parameters on the wind-induced error regarding practical applications such as the development of correction procedures or the selection of suitable design criteria for the sensitive parts of precipitation gauges. In this context, the following gauge parameters are to be noted: the proportions and the shape of both gauge body and orifice rim. In addition, the use of wind shielding devices is one of the most critical factors. The ideal precipitation gauge should have a streamlined body in a shape of a flat plate protected by the wind shield. Yet such gauges are not used at all. A common precipitation gauge consists of an upright cylinder having rather poor aerodynamic properties. Therefore, with regard to a considerable systematic error due to wind, the measured precipitation values have to be corrected.