Numerical simulation studies of rain gage data correction due to wind effect

Investigation of the correction of rain gage measurements due to the wind e ffect is described. The focus is on the effect of the temporal averaging sc ale on the estimation of the wind-induced error correction. Numerically der ived correction formulae for a specific class of rain gage types, along wit h high temporal resolution measurements of rainfall and wind speed, are use d to perform the study. The rainfall measurements are corrected on a variet y of temporal scales ranging from 1 min to 1 month. The results showed the importance of applying the correction procedure at a short timescale, other wise a significant overestimation of the wind-induced bias results. The win d-induced error is characterized by a nonlinear complex behavior dependent on wind speed, rainfall rate, and the microphysical rain structure quantifi ed by a drop size distribution parameter. The estimated correction factors are found to be sensitive to the change of the drop size distribution. Fina lly, comparison with certain formulae reported in the literature showed a s ignificant random scatter of the estimated correction if it is expressed on ly as a function of the wind speed and the drop size distribution character istics are ignored.