A comparative study of the wind characteristics of three typhoons based on stationary and nonstationary models

Abstract

This study presents the results of a comparative study of the wind characteristics of three typhoons presenting similar characteristics, based on stationary and nonstationary models. The original data were collected at four different heights along the seaside of the Fujian Province (China), where the typhoons passed through. First, the run-test method and discrete wavelet transform were employed to evaluate the stationarity and extract the time-varying mean wind speed after data filtering. Then, the gust factor, turbulence intensity and turbulence integral scale were compared. The results demonstrated that the wind characteristics described by the nonstationary model were more centralized and stable than those obtained by the stationary model. Lastly, the power spectral density and evolutionary power spectral density (EPSD) were compared, revealing that the von Karman spectra fitted well the measured spectra. In addition, two methods for the analysis of nonstationary wind spectra were compared. The direct extension from stationary model to nonstationary model was found not to be reasonable from the results of this comparison. Considering the instantaneous energy concentration shown in the EPSD, a nonstationary approach is recommended when analyzing near surface typhoon wind data.