Wind farm effects on weather forecast using HARMONIE-AROME

Wind farms affect the atmosphere due to blockage, wakes and speed-ups. These modifications also affect other meteorological variables such as temperature, humidity and clouds locally under certain meteorological conditions. Therefore, there is a need to include wind farm effects in weather forecasts both for good-quality power predictions, but also for improved weather forecast in general.To evaluate the influence of currently existing on- and offshore wind turbines in Europe, we perform forecasts with the operational NWP model HARMONIE-AROME. The HARMONIE-AROME model is equipped with two wind farm parameterizations (WFPs), namely the WFP by Fitch et al. (2012) implemented by van Stratum et al. (2022) and the Explicit Wake Parameterization (EWP) by Volker et al. (2015) implemented by Fischereit et al. (2024).To represent the existing wind turbines in the simulations, we assembled an European wind turbine database for existing on- and offshore turbines that contains turbine locations and turbine characteristics such as hub height, rotor diameter and thrust curves. For the database we combined seven different data sets with a machine learning gap-filling approach to fill missing information.Using the database, we simulate a winter and a summer month with both WFP and compare them to a control simulation without wind farms for central and northern Europe. The simulations indicate that wind speed, temperature and humidity are affected locally by the presence of wind turbines. The wind farm effects differ in magnitude and sometimes in sign for the two WFPs.Fischereit, J., Vedel, H., Theeuwes, N. E., Larsn, X. G., Giebel, G., Kaas, E. (2024). Modelling wind farm effects in HARMONIE-AROME - part 1: Implementation and evaluation. Geosci. Model Dev., 17, 28552875, https://doi.org/10.5194/gmd-17-2855-2024, 2024Fitch, A. C., Olson, J. B., Lundquist, J. K., Dudhia, J., Gupta, A. K., Michalakes, J., Barstad, I. (2012). Local and Mesoscale Impacts of Wind Farms as Parameterized in a Mesoscale NWP Model. Monthly Weather Review, 140(9), 30173038. https://doi.org/10.1175/MWR-D-11-00352.1van Stratum, B., Theeuwes, N., Barkmeijer, J., van Ulft, B., Wijnant, I. (2022). A one-year-long evaluation of a wind-farm parameterization in HARMONIE-AROME. Journal of Advances in Modeling Earth Systems, 14, e2021MS002947. https://doi.org/10.1029/2021MS002947Volker, P. J. H., Badger, J., Hahmann, A. N., Ott, S. (2015). The Explicit Wake Parametrisation V1.0: a wind farm parametrisation in the mesoscale model WRF. Geoscientific Model Development, 8(11), 37153731. https://doi.org/10.5194/gmd-8-3715-2015