Measurements of the Principal Axis of Frozen Hemispheric Water Droplets

[摘要] Freezing experiments on supercooled hemispheric water drops of an approximate 1mm in diameter were carried out from a point of view of the formation mechanisms of the origin of polycrystallization of frozen cloud droplets. Hemispheric water drops were seeded with a basal plane and a prism plane of single crystalline ice of needle type in the temperature ranges of -17 to -20°C, -20 to -23°C and -23 to -26°C, respectively. Notable polycrystallization occurred when hemispheric water drops were seeded with basal planes of single crystalline ice of needle type. The axial angle between the c-axis of a seeding crystal and that of a frozen hemispheric water drop had a prominent peak around 70° at all temperatures from -17 to -26°C. The axial angle between the c-axes of neighbouring two crystals making up a frozen hemispheric water drop had peaks around 70° 55°C and 40°C. Based upon these angles in this experiment, a possible arrangement of the c-axes of crystals making up a frozen water droplet was proposed.

[学科分类] 大气科学