2019/12/06 by Libbrecht, Kenneth G.
#Atmospheric and Oceanic Physics (physics.ao-ph) #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Popular Physics (physics.pop-ph)
paper · doi:10.48550/arxiv.1912.03230
I examine a variety of snow crystal growth measurements taken at a temperature of -5 C, as a function of supersaturation, background gas pressure, and crystal morphology. Both plate-like and columnar prismatic forms are observed under different conditions at this temperature, along with a diverse collection of complex dendritic structures. The observations can all be reasonably understood using a single comprehensive physical model for the basal and prism attachment kinetics, together with particle diffusion of water vapor through the surrounding medium and other well-understood physical processes. A critical model feature is structure-dependent attachment kinetics (SDAK), for which the molecular attachment kinetics on a faceted surface depend strongly on the nearby mesoscopic structure of the crystal.