Snow in motion -Snow avalanche and Blowing snow-
Abstract: Due to the unpredictability, scarcity and intense destructive power of the snow avalanche, our understandings of its dynamics and internal structures are still far from satisfactory. Our approach to reveal the avalanche will be introduced firstly: fluidized-bed system, chute experiments with snow and ice spheres, experiments at a ski jump with ping-pong balls and observations in nature. On the other hand, the transport of snow by the wind, that is an example of an aeolian transport process, is highly significant for both engineering and climatological reasons. Snow particle motions can be divided into two transport modes in general: saltation and suspension. Since most of the theoretical and experimental research has treated the both modes separately, significant quantitative uncertainties, such as the transition from saltation to suspension, remained. We have developed a new blowing snow model, which took into account all the physical process including aerodynamic entrainment, grain/bed collisions, wind modification, particle size distribution and the turbulent fluctuations on the particle trajectories. Comparisons with the wind tunnel experiments and the field observations in the Antarctica will be also introduced.