Raindrop Axial Ratios

Abstract

Radar techniques involving polarization measurements depend critically on the non-spherical shape of the scatterers. In particular, it is often assumed that the equilibrium axial ratio measured under conditions of laminar flow represents the shape of freely falling raindrops. In the atmosphere, however, raindrops apparently deviate significantly from equilibrium toward more spherical shapes. This deviation can be important in quantitative interpretations of polarization measurements by radar.