The impact of the diurnal cycle of the atmospheric boundary layer on physical variables relevant for wind energy applications

Abstract

This paper provides a quantification of the temporal evolution of physical variables in the atmospheric boundary layer (ABL) relevant for wind energy applications. For this purpose, we use the unique dataset gathered during the BLLAST (Boundary Layer Late Afternoon and Sunset Turbulence) field experiment to validate a large-eddy simulation (LES) model by simulating the complete diurnal cycle of the ABL. In this way, this contribution to the special issue of ACP "The Boundary-Layer Late Afternoon and Sunset Turbulence project" satisfies the purpose of the BLLAST experiment: to provide a dataset for the validation of numerical simulations aiming to study transient BL processes. For wind energy applications, we are investigating the behaviour of different physical parameters which are relevant in the height region where a wind turbine operates. This results in a quantification of the diurnal cycle influence on the vertical wind shear, the stratification and the turbulence intensity in the atmosphere. Further, the impact of different heterogeneous surface conditions on shear near the surface layer of the ABL is investigated.