Abstract
The collection efficiency of uncharged natural snow crystals for the aerosol particles of 0.1 to 6μm in diameter was experimentally examined. Each scavenging test was performed under the condition where the external electric field and phoretic forces were negligibly small. The collection efficiency decreased with the decreasing aerosol size from 6 to 0.2μm in diameter. However, the collection efficiency attained its minimum value at around 0.2μm, and increased with the decreasing aerosol size from 0.2 to 0.1μm. As for the aerosol particles of 0.2 to 6μm in diameter, the interception was considered to be the main scavenging mechanism. The experimental results also showed that the difference between the collection efficiencies of rimed and unrimed snow crystals was small. The collection efficiency determined in the present experiments showed a good agreement with the observational values obtained by Murakami et al. (1981, 1983).
