Performance assessment of 22 CMIP6 climate models for projecting wind climate and wind power over the Mediterranean Sea

This study aims to (1) evaluate the spatial accuracy of 22 CMIP6 climate models in simulating wind climate over the Mediterranean Sea, (2) assess their performance in estimating wind power density across different wind conditions using percentile-based analysis, and (3) examine near-term projected wind climate changes under different SSP scenarios. The models were selected based on the availability of 3-hourly near-surface wind data (10 m height) for historical (1985–2014) and near-term (2015–2024) periods under four SSP scenarios (SSP1-2.6, SSP2-4.5, SSP3-7.0, SSP5-8.5) with consistent spatial coverage. The comparison metrics used to compare CMIP6 individual model output against ERA5 reanalysis data are the bias and the normalized bias supported by statistical test to evaluate the related confidence intervals. The best-performing models were identified based on their ability to reproduce both the long-term average and variability of historical wind speeds with low bias and narrow confidence intervals. Furthermore, a percentile-based evaluation (5th to 95th) was conducted to assess model accuracy across the full range of wind conditions, from calm to high-energy periods, ensuring reliable projections of future wind power density distribution changes. The results show statistically significant differences in model performance across sub-basins, with EC-Earth3 emerging as the most accurate and consistent model for most regions, maintaining normalized differences within ± 0.2 for most percentiles (e.g., Aegean Basin St.11, Alboran Basin St.1). EC-Earth3 demonstrates balanced performance across all wind conditions, while CNRM-CM6-1-HR tends to overestimate wind power density at higher percentiles, particularly in the Balearic Basin (St.2, ~ 0.2–0.6) and Tyrrhenian Basin (St.6, ~ 0.6–0.8). Near-term projections (2015–2024) across four SSP scenarios evaluated through linear trend analysis show partial agreement between ERA5 and EC-Earth3, particularly under SSP5-8.5, but significant regional discrepancies elsewhere. This study provides sub-basin-specific guidance for climate model selection in Mediterranean wind resource assessments, supporting renewable energy planning and climate adaptation strategies.