Local Structure of the Convective Boundary Layer from a Volume-Imaging Radar

Abstract The local structure and evolution of the convective boundary layer (CBL) are studied through measurements obtained with a volume-imaging radar, the turbulent eddy profiler (TEP). TEP has the unique ability to image the temporal and spatial evolution of both the velocity field and the local refractive index structure-function parameter, C2n. Volumetric images consisting of several thousand pixels are typically formed in as little as 1 s. Spatial resolutions are approximately 30 m by 30 m by 30 m. CBL data obtained during an August 1996 deployment at Rocks Springs, Pennsylvania, are presented. Measurements of the vertical C2n profile are shown, exhibiting the well-known bright band near the capping inversion at zi, as well as intermittent plumes of high C2n. Horizontal profiles show coherent 100-m-scale C2n and vertical velocity (w) structures that correspond to converging horizontal velocity vectors. To quantify the scales of structures, the vertical and streamwise horizontal correlation dista...