The Group Structure of Surface Waves in the Black Sea

The purpose of this work is to analyze the statistical characteristics that determine the group structure of surface waves in the Black Sea. The analysis used data from wave measurements taken from a stationary oceanographic platform located in the Black Sea. The isolation of the wave envelope, from which the groupiness factor GFH and the length group GLF were calculated, was carried out by several methods based on the Hilbert transform and the SIWEH function. It is shown that there is a statistical relationship between the excess kurtosis of surface elevations E and obtained by different methods GFH; the correlation coefficient of these parameters in the region $$E > 0.2$$ is in ranges from 0.35 to 0.49. The existence of a statistical relationship indicates that with the development of the group structure of sea surface waves, the likelihood of extreme waves increases. It is shown that the values GFH and GLF obtained within the framework of existing calculation methods can differ significantly quantitatively. At the same time, they equally reflect general trends in changes in the studied parameter, in particular, the dependence of GFH on the excess kurtosis of surface elevation.