A Comparative Analysis of Mesoscale and Microscale Vertical Wind Profiles for Wind Energy Assessment

Accurate characterization of the vertical wind profile is essential for wind energy assessment, particularly in regions with heterogeneous surface conditions that are challenging for mesoscale modelling. In Latvia, extensive forest cover introduces significant surface roughness, increasing uncertainty when extrapolating wind conditions from mesoscale models to local, mast-measured wind profiles.

This study investigates wind speed and direction profiles based on measurements from communication masts at heights between 10 and 85 meters across three sites in Latvia. Two years of 10-minute averaged wind measurements at several height levels are analysed, with additional remote sensing data used where available. The measured wind profiles are compared against mesoscale model products commonly used in wind resource assessment, with a focus on the influence of surface roughness.

The analysis focuses on surface roughness related differences in mean wind speed, wind shear, and directional dependence between mast-based observations and modelled wind fields. The results demonstrate systematic differences between measured and modelled wind profiles over forested terrain, highlighting the limitations of mesoscale models in resolving local surface effects relevant for wind energy applications. The analysis identifies conditions under which these deviations are most pronounced, providing guidance for the interpretation of mesoscale model output at microscale sites.

These findings emphasize the importance of site-specific measurements for wind energy applications in Latvia and provide insight into the sources of uncertainty when applying wind atlases and reanalysis data in regions with complex terrain and surface roughness.