Synoptic and mesoscale winds in the complex terrain of Perdigão

• Type: Article in International Scientific Journal
• Date: 2022

Authors

Coimbra, IL (Author) Other; José Laginha Palma (Author) FEUP

Journal

Title: Journal of Physics: Conference Series

Vol. 2265

ISSN: 1742-6588

Publisher: Institute of Physics Publishing

Other information

Authenticus ID: P-011-5VJ

DOI: 10.1088/1742-6596/2265/2/022010

Abstract (EN): <jats:title>Abstract</jats:title> <jats:p>For modeling complex atmospheric flows in wind energy studies when employing a chain of models, it is necessary to guarantee accurate wind simulations in all models that make up the chain. With this aim, we evaluated the ERA5 dataset (synoptic) and Weather Research and Forecasting (WRF) simulations (mesoscale) of the wind over Perdigão, which will later serve as input to a microscale model. The Perdigão-2017 measurement campaign is one of the latest and largest experiments over a complex terrain, thus being a valuable dataset for the validation of atmospheric models. Previous long-term simulation studies in Perdigão did not employ a highresolution reanalysis dataset for boundary conditions, nudging techniques, planetary boundary layer (PBL) sensitivity analysis, nor did compare synoptic and mesoscale data against local measurements. Here we simulated the wind in Perdigão using WRF with two one-way nested domains (9-km and 3-km horizontal resolutions) during 45 days, evaluating five PBL schemes. ERA5 reanalysis was used as input to the mesoscale simulations and for the spectral nudging in WRF¿s outer domain. Data from the top anemometer of a 100-m tower, located in Perdigão¿s SW ridge, were employed as reference in the evaluation of ERA5 and WRF wind speeds and directions. The hourly-averaged 3-km WRF simulations showed wind speed errors of 2.22 m/s RMSE and ¿0.02 m/s Bias with the YSU PBL scheme. The approximately 31-km ERA5 dataset exhibited total errors of 2.22 m/s (¿0.37 m/s) RMSE (Bias). We attributed the similar ERA5 total error to its smoother wind speed values compared to WRF¿s, despite its coarser resolution, and not to its faithful representation of the wind in Perdigão. WRF overestimated wind speeds mainly between the NW and N sectors as a result of its misrepresentation of the NW mountain range. Despite ERA5 coarser resolution, its smoothed terrain did not seem to greatly affect the wind near the NW direction. Additionally, both ERA5 and WRF wind speed errors vary linearly with the measured wind speed.</jats:p>

Language: English

Type (Professor's evaluation): Scientific