| 20 Oct 2025
Comparing atmospheric boundary layer heights from vertical profiling scanning lidars to ERA5 and WRF
Abstract. The expansion and creation of new wind farms in recent years brings up challenges to manage both inter- and intra- wind farm wake effects. Wake blockage impact heavily relies on atmospheric conditions for determining how long and how intense the wake propagation is. One of these key atmospheric parameters is the height of the atmospheric boundary layer (ABL), which determines the height of the atmosphere most impacted by surface layer wind speed and temperature regimes. Generally lower ABL is united with more stable conditions, and thus greater the wake propagation. Offshore wind farms experience more frequent stable conditions compared to onshore farms, thus boundary layer conditions must be well parameterized to accurately model wake blockage effects. Scanning lidars present a viable solution for boundary layer height determination. In this study, their measurements are compared against ERA5 and WRF ABL model outputs. The lidar acts as a reference for boundary layer conditions, categorizing the ABL for both the mixing (convectively driven) and residual (stably driven) layer heights. Two campaigns, both using WindCube Scan devices, were assessed: one located completely offshore and another on a coastline. The results demonstrate an overestimation of the boundary layer height from both ERA5 and WRF from the offshore site of around 400 m. The coastal site yielded mixed results when comparing the ABL model height to the mixing and residual layer heights derived from the lidar, with a model overestimation compared to the mixing height of 300 m and for the residual height of 750 m. A sensitivity study demonstrates the bias of both models correlates to the ABL diurnal cycle and to temperature flux misrepresentation in the model.
Competing interests: At least one of the co-authors is a member of the editorial board of Wind Energy Science.
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