A Comparison of Roughness Parameters for Oklahoma City from Different Evaluation Methods

The roughness parameters (displacement height, d, and momentum roughness length, Z0) are basic length scales for urban boundary layer flows. There are several methods to evaluate d and Z0 . Burian et. al. (2003) have used the morphological method to obtain d and Z0 values for Oklahoma City, Oklahoma. During the Joint Urban 2003 Field Experiment, a large amount of mean wind and turbulence data has been collected from the 83 m pseudo tower of Lawrence Livermore National Laboratory (LLNL). With the LLNL data we have used different methods, including the mean wind profile method and the temperature variance method to evaluate d and Z0 for Oklahoma City. A comparison of d and Z0 between different evaluation methods is presented. Also the advantages and limitations of these methods are discussed.