Comment on acp-2022-485

Abstract

Most previous studies of aeolian sediment transport have focused on shifting sand surfaces. As a result, sediment transport above gobi (gravel) surfaces is still poorly understood. In this field study, we quantified this transport to provide important support for parameterizing aeolian sediment transport models. We found that the relationship between the Sorensen horizontal sediment transport (Qs) and shear velocity (u*) could be expressed as Qs = ρau*3 ⁄ g(1−u*t2 ⁄ u*2)(α+γu*t ⁄ u*+βu*t2/u*2), where α = –127.4, β = 714.4, and γ = 737.0. The relationship between the vertical sediment transport (F) and shear velocity could be expressed as Fd = CKρa (u*2−u*2), where CK = 0.75. Although Q and F on gobi surfaces can be expressed similarly to previous results (i.e., similar equation forms), the coefficients were much larger than those for a shifting sand surface; that is, sediment transport was higher above the gobi. This difference resulted from the larger sand transport rate and saltation height above a gobi surface, and the larger transport and higher saltation height were related to gravel cover and soil crusts on the gobi surface.