Abstract: In this paper, the values of aerodynamic roughness length over the Hade and Xiaotang regions were calculated under the conditions when the atmospheric stability was in a neutral stratification and there was no windblown sand movement using the wind speed ratio method based on the data of average wind speed and temperature obtained from 10-m-high towers at Hade and Xiaotang in a desert transitional zone of the Taklimakan desert. The correlations between aerodynamic roughness length and underlaying surface, air stability and wind speed were analyzed and discussed. The results are as follows: The aerodynamic roughness length z₀of neutral stratification was in ranges of 1.81×10^-11-1.2×10^-3m and 1.00×10^-11-1.65×10^-3m, their average values were 2.70×10^-5m and 6.05×10^-5m, respectively, and these values were close to those over flat sand surface. The aerodynamic roughness length z₀changed obviously with the change of underlaying surface features. On the whole, the value of aerodynamic roughness length was increased with the increase of atmospheric stability, while the discrete degree of aerodynamic roughness length was increased. There was a significant negative exponential relation between aerodynamic roughness length and wind speed at 2m height. Atmospheric stability has a complex influential action on aerodynamic roughness length, which needs to be further studied.

Key words: desert transitional zone, atmospheric stability, aerodynamic roughness length, wind, Taklimakan Desert