Raindrop-size Distribution from Individual Storms

Abstract

Raindrop data from 34 storms, taken at the University of Miami, Florida, using a raindrop camera, have been analyzed. The relationship between the parameters A and b of the radar reflectivity equation Z=ARB, and the type of drop-size distribution has been investigated. Parameters A and b control not only the pattern of the family of size-distribution curves but also the type of the individual curves. Cases have been plotted against logA and b as rectangular co-ordinates. Reviewed in relation to rainfall types, these showed thunderstorms occupying a region of larger A (300 to 1000) and moderate b (from 1.25 to 1.65). Both A and b are smaller for rainshowers; for continuous rains the value of b ranges widely, from 1.0 to 2.0, while A never exceeds 600. The same sort of data-display has been reviewed in relation to radar echo characteristics to provide a more comprehensive and continuously varying relation between the parameters and the storm-pattern characteristics.