Research on Multifractal Scale Characteristics of Significant Wave Height Time Series

The multifractal detrended fluctuation analysis (MF-DFA) method is used to analyze the significant wave height time series to study the scale behavior of the wave series. The fluctuation function, generalized Hurst exponent, and multifractal spectrum are calculated, and the singularity of fluctuation at different levels of the significant wave height sequence is quantified in detail. The causes of multifractality of significant wave height sequences and the relationship between multifractal parameters and wave height fluctuations were studied. The results show that the fluctuation of the significant wave height sequence has a long-range correlation on the whole and shows significant multifractal characteristics, but the fluctuation function has a crossover phenomenon in the 12–13 days, which divides the fluctuation of the significant wave height series into two parts, and shows different scale characteristics in different intervals. Both the long-range correlation and the broad probability density function of the significant wave height series are the causes of the multifractality, and the long-range correlation is dominant.