Identification of a Novel “Fishbone” Structure in the Dendritic Growth of Columnar Ice Crystals

Ice crystals growing in highly supersaturated air at temperatures near -5 C exhibit a distinctive, nonplanar dendritic morphology that has not been previously documented or explained. We examine this structure and identify its most prominent features in relation to the ice crystal lattice. Developing a full 3D numerical model that reproduces this robust morphology will be an interesting challenge in understanding diffusion-limited crystal growth in the presence of highly anisotropic surface attachment kinetics. [The figures in this paper have been reduced in size to facilitate rapid downloading. The paper is available with higher resolution figures at http://www.its.caltech.edu/~atomic/publist/kglpub.htm, or by contacting the author.]