人工降雪装置における結晶成長による降雪量の実験的検討

抄録

A series of experiments was conducted to estimate the amount of snowfall of dendrite-type crystals produced by an artificial snowfall device that uses the rotary ventilation mesh filter method. An expression is proposed in this paper for the amount of the snowfall. The amount of snowfall (G_s) can be expressed as G_s = η_s V_ai ΔW , where ΔW is effective water content in the crystal growth, V_ai is air mass flow and η_s is snowfall efficiency. The effective water content in the crystal growth (ΔW) is defined as the difference between the specific cloud water content and ice saturation vapor density. The rotary ventilation mesh filter method used in this work had a snowfall efficiency of about 90%. Even for a large amount of cloud water content, we observed only a very few super-cooled cloud droplets on snow crystals. Therefore, we can deduce that the cloud water content should contribute to crystal growth directly. We report here measurements of snowfall as a function of several input parameters and verify the validity of the proposed relationship.