Snow Particle Fragmentation Enhances Snow Sublimation

Abstract. Fragmentation of snow particles, where dendritic snowflakes transform into spherical shapes upon impact with surface and other particles during drifting and blowing snow events, plays a critical role in shaping snow dynamics. This phenomenon is important because it influences the size distribution and concentration of snow particles, affecting mass flux and sublimation rates. Currently, prevailing drifting and blowing snow models ignore the snow particles fragmentation, leading to heightened uncertainties in predicting flow structures and sublimation rates. Here, we aim to quantitively investigate the impact of snow particle fragmentation on sublimation. We establish a drifting and blowing snow model considering the snow particle fragmentation process and investigated the effects of fragmentation on drifting and blowing snow. The results show that fragmentation enhances the sublimation of blowing snow and changes the airborne particle size distribution. The sublimation rate of saltating snow particles increases 11 % on average, and that of suspension snow particles increases 76 % on average, when the friction wind speed is between 0.3 m/s to 0.5 m/s. These findings have important implications for improving the physical dynamic model of drifting and blowing snow, which may contribute to predictions in snow hydrology and climate models.