Quantitative Investigation of Rate Determining Process of Growth of Snow Crystals

[摘要] Growth of snow crystals, i. e. growth of ice crystals from vapor is considered to occur by the following three processes: (1) a surface kinetic process for incorporating water molecules into the crystal lattice, (2) a diffusion process of water molecules in air towards the crystal surface, (3) a heat conduction process of the latent heat of sublimation. The resistance of each process is not constant, but depends on growth conditions such as supersaturation, the diffusion constant of water molecules in air, and also on crystal size. The purpose of the present sudy is the quantitative investigation of the role of each process as a rate determining process, and a discussion of the dependence on crystal size of the growth rate in the case of two-dimensional nucleation growth and in the case of spiral growth under various growth conditions. The results are interpreted from the viewpoint of the change of resistances of individual processes with increasing crystal size.

[学科分类] 大气科学