Drifting Snow Particle Fragmentation Enhances Blowing Snow Sublimation

Snowflakes usually have different shapes for different formation environments. When drifting snow happens, fragmentation makes snowflakes transform into rounder shapes and releases more small particles. This is important because it changes airborne snow particles' size distribution(SPSD) and concentration, affecting blowing snow mass flux and sublimation rate. However, current drifting and blowing snow models ignore this, increasing uncertainty in predicting snow mass and energy balance. Here, we develop a drifting and blowing snow model considering the snow fragmentation process during particle-bed interaction and investigate the effects of fragmentation on drifting and blowing snow. The results show that compared to not considering fragmentation, fragmentation changes the SPSD, resulting in an enhancement of mass flux and sublimation rate. The sublimation rate of blowing snow increases by 75% on average under a moderate wind speed ( with a friction velocity between 0.3 and 0.5 m/s). Initial SPSD also affects the final sublimation rate, which indicates that SPSD is an important factor for blowing snow modeling.