Cloud layers, particle identification, and rain-rate profiles from ZRVf measurements by clear-air Doppler radars

Abstract

Networks of radars that point almost vertically and continuously measure the vertical profile of the horizontal wind will, in the future, be operated at many locations around the world. Although such radars are designed to measure the Doppler-sensed movement of clear-air refractive-index inhomogeneities, they are an exceptional tool for sensing precipitation ice and water particles in clouds. Because of the low detection threshold and long averaging time of these radars, water-particle-size distributions can be measured down to 100-μm diameter and mean vertical fall velocities Vf as small as 0.2 m s can be accurately measured. In this paper, data are presented from two events in which clouds form, intensify, and finally produce precipitation. -from Authors