Grain size dependence of eolian saltation lengths during snow drifting

Eolian saltation, a primary process in the transport of fine granular material by wind, produces a variety of geophysical effects on Earth and other planetary surfaces. Wind-tunnel experiments were carried out to investigate the dependence of saltation on grain size. The saltation length of snow particles was estimated at size intervals of 0.05 mm in diameter by measuring local vertical mass fluxes in 17 snow collectors arrayed at the lee end of the snow surface. The measured mean saltation length of snow particles of 0.01 - 1 mm in diameter ranged from 0.1 to 1.0 m at wind velocities of 5 - 10 m/s. Mean saltation length decreased with increasing diameter and decreasing wind speed. We suggest that the probability of the saltation length of a particle at each diameter is described by a monotonically decreasing distribution function, that is, the shorter the saltation length, the higher the frequency of its occurrence. One ramification of this distribution is that the mean saltation length does not imply the dominance of saltating particles of this length.