Laboratory and Numerical Studies of the Convective Boundary Layer Capped by a Strong Inversion

The convective boundary layer (CBL) with a wide range of stability issimulated experimentally using a thermally stratified wind tunnel, andnumerically by direct numerical simulation (DNS). The turbulencestructures and flow characteristics of various CBL flows, capped bya strong temperature inversion and affected by surface shear, areinvestigated. The various vertical profiles of turbulence statisticssimilar to those from the observed CBL in the field are successfullysimulated in both the wind-tunnel experiment and in DNS. The comparisonof the wind-tunnel data and DNS results with those of atmosphericobservations and water-tank studies shows the crucial dependence of theturbulence statistics in the upper part of the layer on the strength of theinversion layer, as well as the modification of the CBL turbulence regimeby the surface shear.