On the Mechanism of Spongy Hailstone Growth

Abstract

It is argued that the mechanism of spongy hailstone growth, in certain conditions, is analogous to growth in conditions of constitutional supercooling. If so, this allows the application of the large body of information on, and theory of, crystallization in constitutional supercooling to be applied to spongy hailstone growth. Justification of this view is from fundamental principles, from observations of spongy icicles, and from the orientation fabrics of artificial spongy hail. Application to natural hail is restricted to cases in which the crystal size is fairly large.