Accretion rates of cloud drops, raindrops, and small hail in mature thunderstorms

Abstract

Some “best estimates” of collision efficiencies, including the influence of charges and fields from zero to those found in mature thunderstorms, have been made and incorporated into calculations of instantaneous mass accretion rates of the full range of cloud drop and raindrop sizes, an embryonic hailstone, and two larger hail stones. The implication drawn from these calculations is that instantaneous particles mass growth rate in the continued quasi steady-state phase of precipitation growth in mature thunderstorms or electric fields of several hundred volts per centimeter can be speeded up by more than an order of magnitude by electrical forces when all particles involved are less than 100 μ. The effect decreases with increasing particle size.