Morphology of ice droxtals grown from supercooled water droplets

Abstract

This study describes the growth modes of polyhedral ice crystals grown from spherical ice crystals formed by freezing of supercooled water droplets. Frozen water droplets were grown on a thin glass plate at -15 and -7°C and at humidities above and below water saturation. In the case of growth at -15°C and at a humidity above water saturation, a frozen water droplet grows into an 8-faced ice crystal through a 20-faced ice crystal, while in the case of growth at -15°C and at a humidity between the ice saturation and the water saturation, it grows into an 8-faced ice crystal with truncated edges and corners through an 8-faced ice crystal with curved and flat surfaces. The growth modes at -7°C and at humidities above and below water saturation are almost the same as those at -15°C, except that the axial ratios c/a of the droxtals at -15°C are about 0.95 but those at -7°C are about 1.04.