Assessing the Accuracy of a Three-Year High-Resolution Mesoscale Wind Farm Wake Simulation with Lidar and Satellite Radar Data

Abstract. The rapid expansion of wind farm installation in the North Sea results in an increased need for understanding their influence on the local atmosphere, as well as the interactions between them. Wind farm operation and power production are affected by wakes produced both within the wind farm and by upwind wind turbines. To accurately estimate wind power production, it is essential to quantify the effects behind these extended wind speed deficits using mesoscale atmospheric modelling. This study presents a three-year-long mesoscale analysis using the Weather Research and Forecasting (WRF) model at a horizontal resolution of 1 kilometer. The simulations are evaluated against lidars located in the Southern Bight of the North Sea in the vicinity of the large Belgian-Dutch offshore wind farm cluster, illustrating that the model performs adequately. Coupling the mesoscale atmospheric model with the Fitch wind farm parameterization (WFP) scheme significantly improves simulation accuracy, particularly in regions frequently affected by wake effects. An analysis of the model performance under different atmospheric boundary layer (ABL) stratification conditions shows that the model performs better under less extreme stability cases, while a complementary evaluation of upstream, intra-farm, and downstream wake characteristics further highlights the benefits of using the Fitch WFP scheme in WRF. In addition, synthetic aperture radar images are compared to model outputs for specific wake events, indicating that the wind farm parameterization scheme effectively captures wake structures at the analyzed timestamps.