Photomicrographs of section planes can be converted to video format, digitized, and analyzed on a desk computer. The structure of snow consists of two interconnecting. The problem of observing all three phases is taken up only briefly in the last section. The ice phase can be idealized as a complex assembly of polyhedra, tubes, plates, spheres, needles, and shells. Figure 1 is an attempt to represent older snow that has recrystallized and sintered.
Snow is characterized by connectivity of the pore space.
Pore connectivity decreases as density increases. All snow properties pertinent to engineering and hydrologic problems depend on snow structure. The simplest method is to disaggregate the structure into individual grains which can be studied under a magnifying glass, microscope, or macroscope using incident reflected light or transmitted polarized light as shown in figure 2 left. This yields important qualitative information on crystal morphology, and possibly some quantitative indices such as maximum crystal size. It is a quick and practical field method, and at present it is probably the only feasible method for classifying snow in operational hydrology, avalanche forecasting, ski area management, ski racing, or whenever one needs to be specific about snow crystal morphology.