Field studies of aerodynamic roughness length

The aerodynamic roughness length (z0) is governed by surface roughness and is an important parameter in many surface and climate related processes. The transport of windblown particles is affected substantially by variations in surface roughness; yet, not much attention has been devoted to improving knowledge of this parameter. In this paper, it is demonstrated that radar backscatter can be used as an indication of variations in z0 on a regional scale and, therefore, can improve the ability to assess the susceptibility of a given surface to aeolian processes. Field studies were conducted in the south-western desert of the United States, in which z0 values were obtained by in situ measurements of the boundary layer wind profile. Those sites were also assessed by airborne radar. Correlation coefficients between the radar data and z0 are between 0•74 and 0•81