Analysis of diabatic flow modification in the internal boundary layer

Measurements at two meteorological masts in Denmark, Horns Rev in the sea and Høvsøre near the coastline on land, are used to analyze the behaviour of the flow after a smooth-to-rough change in surface conditions. The study shows that the wind profile within the internal boundary layer is controlled by a combination of both downstream and upstream stability and surface roughness conditions. A model based on a diffusion analogy is able to predict the internal boundary layer height well. Modeling the neutral and long-term wind profile with a 3 layer linear interpolation scheme gives good results at Høvsøre. Based on a comparison with a numerical model and the measurements, the constants in the interpolation scheme are slightly adjusted, which yields an improvement for the description of the wind profile in the internal boundary layer.