Characterization of the offshore wind dynamics for wind energy production in the Gulf of Lion, Western Mediterranean Sea

A ground-based wind lidar system has been deployed on a coastal landmass off Marseille in the Gulf of Lion, western Mediterranean Sea. This location holds significant relevance as it anticipates the imminent deployment of floating wind farms. Over the course of one year, a comprehensive wind dataset was collected by a lidar profiler at altitudes ranging from 60 to 220 m above sea level, aiming to assess the wind resource potential. This study presents an analysis of monthly wind metrics, including key parameters such as wind speed, wind shear exponent, and turbulence intensity. Weibull distributions are provided, along with their scaling and shaping parameters, to elucidate the probability distribution of wind speeds. The focus extends to the diurnal variation of wind metrics and monthly wind speed vertical profiles. Our results indicate that, at an altitude of 140 m above sea level, the one-year average wind speed is 8.3 m/s, with a turbulence intensity (TI) of 13.0 %. The mean wind shear exponent is quantified at 0.077. Notably, the highest wind speeds are consistently observed between 12:00 and 15:00, coinciding with lower values of TI and wind shear exponent, while night-time reveals high levels of both TI and wind shear exponent. Furthermore, an examination of wind direction unveils a bi-modal pattern with a slight variation, specifically wind veer, at each measurement height relative to the 140 m altitude. Additionally, our study explores low-level jets (LLJs), revealing that 80 % of these phenomena occur at altitudes below 140 m, predominantly during the summer period. The mean LLJ core speed, averaged across all measurement heights, is found to be 8.4 m/s.