An evaluation of estimations of atmospheric turbulence from coherent Doppler lidar data

Remote sensing of atmospheric turbulence offers great advantages over conventional in-situ methods, but there are questions with regard to the quality of turbulence measurements using the coherent Doppler lidar. This is due mainly to inherent volumetric averaging over each range gate and the assumptions required to estimate the effects of smaller (and therefore not directly measured) scales of motion on turbulence quantities. The data from the stare scans that were performed by the Karlsruhe lidar on two days (4th and 5th of October) in Germany and that from the ASU lidar for three days (6th, 7th and 14th of July) in Oklahoma are analyzed and compared with sonic data to evaluate estimation methods. Several clarifications of methods used for estimation of turbulence information from lidar data are presented. Spectral analyses are carried out on both lidar and tower data and the results are compared. Integral length scales and local energy dissipation rates are obtained using a well-known relationship between the structure function and dissipation. The estimates obtained are compared with estimates from sonic anemometer measurements. Intercomparison of estimates from the lidar data and sonic data shows some degree of agreement.