Capillary rise in snow

Snow is a complex porous medium where liquid water may rise to several centimeters high due to capillary rise. Previous experimental measurements in cold laboratory on wet snow samples allowed us to relate the capillary rise level with snow characteristics (porosity, grain size). In this study, a network model was adapted to snow to simulate this phenomenon. The pore texture of a wet snow block is simulated by a cubic lattice of cylindrical tubes. Tube lengths are the same, equal to the mesh size of the lattice. Their circular sections vary with the two dimensional pore size distribution, computed from image analysis of thin sections. At a given height, a tube contains water if the two following conditions are fulfilled: first, it should be thin enough in radius so that capillary pressure balances hydrostatic pressure at this level; second, there exists a continuous path of such links that connects the bottom of the lattice. Simulations are systematically compared to observations of the maximum level of capillary rise for ten different snow samples. Simulated profiles of liquid water content are compared to vertical thin sections of three refrozen samples of saturated snow. Copyright (C) 1999 John Wiley & Sons, Ltd.