The Origin and Concentration of Ice Crystals in Clouds
Abstract Ice crystals in supercooled clouds may form upon ice nuclei, or they may arise through secondary processes. Two of these secondary ice “multiplication” mechanisms are discussed in some detail: the rime-splintering process and the mechanical fracture of ice particles. The nature of the water-drop size distribution has an important bearing on secondary ice production. Confident predictions of ice particle concentration can only be made in a few limited cloud situations. This is a serious handicap in assessing the feasibility of artificial rainmaking through the ice crystal process.