Relations between aerodynamic and surface roughness in a hyper‐arid cold desert: McMurdo Dry Valleys, Antarctica

Studies of boundary‐layer winds and surface roughness characteristics of unvegetated rocky desert surfaces provide new insights into the relations between aerodynamic roughness and surface roughness, as described by the roughness density ( λ ). The description of non‐erodible roughness by the roughness density ( λ ) is shown to be valid for rocky surfaces as well as sparsely vegetated surfaces and simulated surfaces in a wind tunnel. There is a good relation ( r 2 = 0·71) between aerodynamic roughness and roughness density ( λ ), allowing use of the threshold friction velocity ratio to predict sediment transport rates on these surfaces. Copyright © 2004 John Wiley & Sons, Ltd.