DIURNAL VARIATION OF NEAR-SURFACE WIND SPEED: MULTIFRACTAL ANALYSIS

In this work, we analyze the diurnal variation of multifractal properties of wind speed. We applied Multifractal detrended fluctuation analysis (MFDFA) on hourly wind speed records from two stations in the Brazilian state of Pernambuco, one at coastal and one at inland location. For the period from 2011 to 2018, we constructed 24 daily series (one for each hour of day, 0–23 h) and calculated the parameters of the multifractal spectrum [Formula: see text]: the position of the maximum [Formula: see text], spectrum width [Formula: see text] and skewness [Formula: see text], which quantify the persistence, degree of multifractality and contribution of small/large fluctuations, respectively. We found that these properties exhibit diurnal variation, which is related to the diurnal variation of wind speed, being more consistent for inland Petrolina station, in the region that is considered to be one of the most promising for wind energy generation. For this station, wind speed shows stronger persistence (higher [Formula: see text] values) and weaker multifractality (lower [Formula: see text] values) during the daytime when wind speed is higher. This indicates that the diurnal variation of the complexity (evaluated as multifractality) of wind speed dynamics could be used as additional information, along with wind speed, to identify the periods during the day when conditions for wind energy generation are most favorable (satisfying both, high wind potential and more stable wind dynamics).