A laboratory study of secondary ice particle production by the fragmentation of rime and vapour-grown ice crystals

Abstract

Laboratory experiments have been performed to study the strength of rime and vapour-grown ice crystals to investigate the possibility that fragmentation may occur following collisions in cloud. The results show that fragmentation of rime is very unlikely to occur in natural clouds. Vapour-grown crystals are found to be considerably more fragile, with dendrites the weakest crystal habit. In the experiments one or two microscopic fragments were produced. Collisions between dendritic crystals and graupel particles may be able substantially to enhance ice crystal concentrations in some clouds.