Observation of Ice Crystals in Supercooled Fog

[摘要] n cloud physics, it is very important to study the phase change in clouds from supercooled droplets to ice crystals and to observe whether or not the snow crystals coexist with supercooled droplets. The author made the observation of ice crystals in a supercooled fog at Asahigawa from January through March 1967.When ice crystals coexisted with supercooled fog, ice crystals of dendritic type, side plane type and irregular type were observed, the mean size of which was about 100μ. When the supercooled fog disappeared, small ice crystals such as prism and plate were observed. They were of about 20μ and many of them were twinlike crystals.From the results of the present observations, it was found that the snow crystals of spatial dendrite type, side plane and irregular types were formed by the adhesion of supercooled droplets to a snow crystal and that ice crystals of twin shape were formed not by the collision of two ice particles but by the sublimation on one embryo.

[学科分类] 大气科学