Exponential Size Distributions of Raindrops and Vertical Air Motions Deduced from Vertically Pointing Doppler Radar Data Using a New Method

Abstract

Raindrop-size distributions and vertical air motions are deduced from vertically pointing C-band Doppler radar data by using a new method (described in Hauser and Amayenc, 1981) which assumes the raindrop sizes are exponentially distributed [N0 exp(??D)]. Results gathered in stratiform rain precipitation after the passage of a cold front are presented and compared with those obtained by using the well-known Rogers approach. The new method which does not a priori require the knowledge of N0 values is capable of detecting spatial and temporal variations much better than the Rogers method. Taking this variability into account allows one to find relationships involving three rainfall parameters with good accuracy.