Annals of Glaciology 6 1985 © International Glaciological Society GRAIN COARSENING OF SNOW PARTICLES IMMERSED IN WATER AND SOLUTIONS

In order to clarify the metamorphic process of snow particles immersed in water, distributions of grain size were examined as functions of time (0.1 to I 000 hrs) and impurity concentrations. When disaggregated snow particles were immersed in water kept at 0 ·C, each particle became spherical and grain coarsening took place with time. The average diameter increased with cube root of time and the average volume increased in proportion to time. Grain coarsening was not detected in a kerosene environment. In solutions of glucose, NaCI, HCI and dextran, the growth rate was controlled by the concentration and the diffusivity of the solute. The higher concentration and the lower diffusivity, the grain coarsening was controlled. The grain coarsening is explained by the disappearance of relatively small particles and growth of relatively large ones, caused by differences of the equilibrium temperature of each particle if the total ice mass is conserved