Multi-scale simulations of wind farm impacts on nighttime near-surface temperature in complex terrain

Various studies have shown that wind turbine wakes can induce temperature variations. Investigating these effects near the ground is particularly important for assessing their potential impact on vegetation and human activities. In this study, the multi-scale Meso-NH/SURFEX/EOL modeling framework, which includes coupled atmosphere, land-surface and actuator models, is used to evaluate the impact of the Ensemble Éolien Catalan wind farm on ground and near-surface temperatures, as well as terrain-specific flow dynamics during a stable nocturnal radiative cooling event associated with frost risk in nearby vineyards. The simulations are performed using nested domains to dynamically downscale the atmospheric conditions from the operational weather forecast AROME-1.3km to a horizontal resolution of 5 m, allowing explicit representation of turbine wakes through rotative actuator disk representation. Turbine-induced meteorological variations are quantified by comparing simulations performed with and without the actuator model. The results reveal that near-surface meteorological responses arise from the combined influence of individual turbine wakes and the large-scale impact of the wind farm, which modifies the flow dynamics and temperature field. In the wind farm, a mean near-surface warming of approximately 0.4 °C is found, with localized temperature increases reaching up to 1.6 °C in the near wake of individual turbines. The strongest perturbations occur for turbines located within valleys, where strong temperature inversions enhance turbine-induced temperature changes. In addition, the wind farm shifts the position of a convergence zone associated with a katabatic flow by about 100–400 m, producing warming anomalies of up to 2 °C along the displaced meteorological front.