статья в журнале

En

Physical Oceanography

ISSN:0928-5105
eSSN:1573-160X

2018

10.22449/1573-160X-2018-6-489-500

The results of characteristics' analysis of the wind wave breaking (length, velocity, direction) obtained in the Black Sea in September-October, 2015 from the oceanographic platform in Katsiveli are presented. Wave breaking was recorded by a video camera synchronously with the measurements of wind waves and meteorological parameters. The algorithm based on calculating the threshold determined at analyzing the distribution function of the video signal brightness was applied to identify breaking using the video records. The optical equipment used in the experiment made it possible to reliably identify the breaking generated by the waves with the lengths greater than 4 m and the phase velocities exceeding 2.5 m/s. The data obtained correspond well to the model conceptions of O.M. Phillips which were developed for the equilibrium interval of the wind wave spectrum. The histograms of the wave breaking velocities at the wind speeds 10-16 m/s are given. It is shown that at the developing waves, the breaking waves' phase velocity can reach that of the wind waves corresponding to the spectral peak, while at the developed waves, no breaks with the velocities exceeding a halfphase one of the waves corresponding to the spectral peak were observed. Probability densities of the breaking lengths in the wind speeds' measured range are described by the power law with the exponent -3.23. Distribution of the breaking orientations is described well by a degree of the angle cosine, at that the exponent decreases linearly from 5 to 4 with the wind speed increase from 10 to 16 m/s.

WIND WAVE BREAKING, IN SITU STUDIES, WAVE BREAKING ORIENTATION, BREAKING LENGTHS' DISTRIBUTION, WIND WAVES' SPECTRUM

2018-12-12 15:49:00