Boundary layer structure and parameterization uncertainties affecting wind turbine hub-height predictions: A comparative assessment of New England and Florida

Abstract. As wind energy development expands to diverse geographical regions, understanding the complex atmospheric conditions that turbines encounter is essential for accurate resource assessment and operational forecasting. This study presents an analysis of boundary layer structure, thermodynamic forcing mechanisms, and model parameterization uncertainties affecting hub-height winds using North American Mesoscale Forecast System (NAM) data and one-dimensional RANS simulations. Our analysis reveals important regional and seasonal variations in atmospheric boundary layer characteristics between New England and Florida. In New England, hub-height to PBL ratios frequently exceed critical thresholds during summer convective conditions, indicating turbine operation above the shallow atmospheric boundary layer, while Florida maintains more consistent conditions with ratios well below these thresholds year-round. Thermodynamic forcing shows similarly distinct patterns, with New England experiencing strong seasonal CAPE variations between winter and summer compared to Florida's consistently elevated values. Systematic evaluation of NAM turbulence parameterization reveals moderate correlations with resolved turbulence but significant biases across the TKE spectrum. Controlled numerical experiments demonstrate that different turbulence closure schemes and vertical resolution configurations produce substantial variations in power density estimates, with the greatest deviations occurring under stable conditions.