Terminal Fallspeeds of Raindrops

Abstract

For the relationship of terminal fallspeed to size in the raindrop-size range 0.1≤d≤5.8 mm, a two-domain regression scheme is presented. The third-degree regression divided at d= reproduces the basic data from Gunn and Kinzer within 0.70% throughout the size range. The need to return to basic physical concepts is indicated, and suggests a path to a more satisfactory understanding and a more complete analytical expression of the relationship.