Doppler Radar Observation of Drop Sizes in Continuous Rain

Abstract

Doppler radar observations were made of continuous rain in a situation where particles with terminal velocities of up to 5 m sec?1 were present above the 0C isotherm. It is shown that under these conditions, the presence of drops having diameters of up to 4 mm just below the melting layer can be accounted for without the occurrence of locally enhanced coalescence. Drop-size distributions just below the melting layer show that extensive breakup of large drops did not occur there. In the few thousand feet just above the ground, large concentrations of raindrops having diameters of less than 0.5 mm were observed.