On snow crystals of double plate type grown from ice fragments

Abstract

Seeding experiments were conducted under the condition of water saturation at -15°C temperature by the use of ground ice particles. The diameters of the center circles of double plate snow crystals were smaller than about 25μm. On the other hand, the diameters of irregular center nuclei were larger than about 25μm. Seeding experiments using natural snow crystals were also done for the cases of snow flakes, dendrites and needles. The generation of secondary ice particles was most abundant in the case of dendritic snow flakes. It was also found that needle crystals were fractured in free fall, and the fractions grew to become tall capped snow crystals. According to the observation of snow crystals at the summit of Mt. Teine in Hokkaido, it was noted that ice fragments which floated in the air contributed, to some extent, to the process of multiplying snow crystal growth.