Estimation of atmospheric boundary layer fluxes and other turbulence parameters from Doppler radar and lidar data

Retrieval techniques for the extraction of boundary layer turbulence parameters from Doppler radar and lidar measurements are described. Two sheared convective boundary layers (CBL), observed during the PHOENIX II 1984 experiment and the FIFE 1987 experiment respectively, are studied. Three case studies are included: single Doppler analysis using lidar data collected in range height indicator (RHI) mode during FIFE, single Doppler analysis using a K-band radar data in plane position indicator (PPI) mode during PHOENIX II, and dual Doppler analysis using the X-band scan pairs during PHOENIX II.;Using dual Doppler data from PHOENIX II, flow patterns, turbulence statistics and energy balances are studied through three-dimensional wind and thermodynamic retrieval. We have carried out tests and comparisons on the schemes for processing dual Doppler data in the CBL. Two adjustment methods are introduced as procedures for correcting errors in the vertical velocity. By estimating the turbulent kinetic energy dissipation rate from the Doppler spectral width, we have developed two methods to derive the heat flux. Possible spatial organizations of convective eddies are discussed. Validity of the analysis techniques are tested by control runs using simulated data and intercomparison of the results from various measurements (single and dual Doppler radars, aircraft, tower and surface stations).;Using single radar and lidar data, we have developed and tested analysis techniques which are extensions of the Velocity Azimuth Display (VAD) or RHI methods. Profiles of the mean wind, velocity variances and momentum fluxes in the mixed layer and in the region immediately above the mixed layer are obtained. The results from FIFE show indications of a critical layer above the mixed layer and the nonlinear effect of steepening of gravity waves. The results from PHOENIX II confirm that the turbulence activities in the CBL were strongly affected by entrainment processes above the mixed layer.