Atmospheric Boundary Layer

In the last decades, large-eddy simulation (LES) has become a powerful tool to study turbulent transport and mixing in the ABL. Numerical simulations have been used to investigate the impact of different surface types (homogeneous, heterogeneous, flat, complex topography) on turbulent fluxes of momentum and scalars, such as temperature, water vapor and pollutants. Recently, LES studies of the interaction between ABL turbulence and wind turbines, and the interference effects among wind turbines have been carried out, in order to understand the impact of wind farms on local meteorology as well as to optimize the design (turbine siting) of wind energy projects. However, there are still some open issues that need to be addressed in order to make LES a more accurate tool for simulations of ABL flows. The main weakness of LES of the ABL is associated with our limited ability to accurately account for the dynamics that are not explicitly resolved in the simulations (because they occur at scales smaller than the grid size). The purpose of our studies is to improve subgrid-scale parameterizations and, thus, to make LES a more reliable tool to study land-atmosphere interactions.