Waves Eddies and Turbulence Observed over Owens Valley

The turbulence and vortical characteristics of the airflow in Owens Valley have been examined using data obtained from a recent field project, the Terrain-induced Rotor Experiment (TREX) that took place in the spring of 2006. Spectral and wavelet analysis of the high-rate data sampled by the research aircraft, University of Wyoming King Air, indicated coexistence of small-scale turbulence (< 1 km) and mesoscale eddies (1-3 km) in Owens Valley during the documented westerly (i.e., with a predominant westerly component in the prevailing mountaintop winds) events. Several hypotheses regarding the turbulence and mesoscale eddy generation mechanisms, including K-H type shear instability, boundary layer and boundary layer separation, and differential heating induced valley-scale circulation, have been proposed and explored. The preliminary results suggest that the observed mesoscale eddies and turbulence are likely generated by the interactions between gravity waves, a pre-existing sheared layer, and a surface heating driven convective boundary layer.