Power spectrum and multifractal detrended fluctuation analysis of high-frequency wind measurements in mountainous regions

The main objective of the study was to investigate the temporal features of the wind speed in complex mountainous terrains that are important for the assessment and development of wind energy. Six high-frequency records of 10-min averages of wind speed measured in Switzerland are investigated in order to better characterize their inner time dynamics. All the wind speed time series are modulated by components periods of 1 day and 12 h, linked with the temperature and pressure daily variation due to the sunset and sunrise. Furthermore the time dynamics of the wind speed is characterized by the presence of two different timescale ranges, separated by a crossover at about 7 days: persistent and multifractal at larger timescales and antipersistent and monofractal (or weakly multifractal) at smaller ones. The found features do not seem to depend on the altitude, because all the wind speed series share the same dynamical characteristics. The results of this comprehensive study can be utilized to better understand the mechanisms governing the time dynamics of wind speed and to perform a better wind energy assessment and management.