Coupling of Land and Atmosphere Over Complex Terrain as Observed by Lidar and Wind Profiler Radar

The Marshall-2001 experiment was conducted south of Boulder/Colorado to study the dynamics of the atmospheric boundary layer (ABL) over hilly terrain. Two remote sensing techniques, an elastic backscatter lidar and a multiple antenna profiling radar, were used to observe the mixing in the ABL. In addition, fluxes of sensible and latent heat, soil heat flux and net radiation were recorded and traditional methods to measure boundary layer profiles (radiosondes, tethersondes) were used. The simultaneous use of multiple remote sensors allows one to visualize more fully the rapid dynamical coupling of land and atmosphere over complex terrain. The importance of large scale coherent structures (ejections and sweeps) in the ABL and the rapid collapse due to the appearance of low level clouds are presented. Calculations of regional scale shear stress from the wind profile measurements and comparison with surface friction velocity measurements are made.