The probabilistic turbulence profiles of tropical cyclones in open and flat terrain

Abstract

The fluctuating winds are usually characterized in the frequency domain by the power spectral density (PSD) function and the coherence function, in which the turbulence intensity and turbulence integral scale are key parameters to describe the gust characteristics of turbulent winds. These parameters estimated from tropical cyclone (TC) observations show significant scattering. Starting from a critical review of the state of the art, the Von Karman spectra are chosen for the TC winds. The turbulence intensity and the turbulence integral scale used in wind spectral functions are discussed in detail. By introducing randomness into the empirical models, the probabilistic longitudinal turbulence profiles of TCs are derived from a wide collection of field measurements with open and flat terrain in the literature. Moreover, the probabilistic models of the lateral and vertical turbulence components are obtained by assuming proportionality between these two components and the longitudinal one. The mean and standard deviation of the developed models for TCs are compared with those defined in the seven major wind loading codes worldwide as well as the model given by Solari to testify these models and illustrate their differences to synoptic winds.