Boundary-Layer Regimes and Wind Energy Climate Resilience in North Africa: A Comparative Assessment of Egypt and Morocco

Abstract. Egypt and Morocco have Africa's most ambitious wind energy programs, yet the climate resilience of their wind resources remains poorly constrained by conventional approaches that overlook fundamental atmospheric processes. Here we introduce a boundary-layer regime framework that classifies wind farm sites according to their dominant wind-generation mechanism—Mechanically Forced (M-BL), Thermally Forced (T-BL), or Complex Forced (C-BL)—and apply it to twelve wind farms across Egypt's Gulf of Suez and Morocco's Atlantic and Mediterranean coasts. Using a consistent CORDEX-Africa CMIP5 ensemble under RCP 8.5 through 2100, combined with validated baseline wind power density from ERA5 reanalysis, we analyze projected changes using the delta change method. We find a hierarchy of climate vulnerability governed by boundary-layer physics. Egyptian M-BL sites and Moroccan southern M-BL sites show the greatest resilience (mean ΔWPD₅₀ = +1.6 %), while Moroccan T-BL sites (Essaouira, Taza) and C-BL sites (Tanger I, II) show larger declines (mean ΔWPD₅₀ = −5.5 % and −10.8 %, respectively). The Mediterranean SST corridor creates a shared threat with divergent outcomes: Tanger remains viable because topographic acceleration at the Strait of Gibraltar partially compensates for the weakened thermal gradient, whereas the Egyptian Mediterranean coast has no wind farms because it lacks such compensation. The Zafarana case shows that urbanization can override M-BL resilience. The regime hierarchy is consistent with a companion CMIP6-based analysis, suggesting that the framework is robust to scenario-generation and ensemble-size differences. Our framework provides a physics-based, universally applicable tool for climate risk assessment in wind energy development.