Large-Eddy simulation of the diurnal cycle of the atmospheric boundary layer using boundary conditions derived from CASES-99

A simulation of a diurnal cycle of atmospheric boundary layer (ABL) over a homogeneous terrain is performed using Large Eddy Simulation (LES) with the Lagrangian scale-dependent dynamic subgrid-scale model. The geostrophic forcing, surface boundary condition and initial conditions are based on the setup for the second GABLS single column model inter-comparison study. In spite of the highly idealized nature of forcings and boundary conditions, the simulation results display good qualitative agreement with the observations from CASES-99 study and capture the well-known features of the diurnal cycle of ABL. The simulations are performed at different resolutions to assess the impact of numerical resolution on the quality of the results. The preliminary results obtained lend credibility to the feasibility of multi-day large-eddy simulations of the diurnal cycle of the ABL