Abstract
In 1964, R.R. Rogers proposed a method for estimating vertical air velocity in rainfall which is based on the Marshall-Palmer raindrop size distribution. Many investigators have shown that there are deviations from the Marshall-Palmer distribution such that the intercept N0, and the shape may vary. Essential to Rogers' method is the relationship between reflectivity Z and Doppler fall velocity V̄. A numerical method has been used to obtain V̄ versus Z relationships for raindrop size distributions different from those of Marshall and Palmer and to compare these with results obtained using Rogers's method. Thus errors that are likely to occur in estimating vertical air motions have been evaluated and are shown to be a maximum of 1.4 m s−1.
