Wavelet analysis of non-stationary sea waves during Hurricane Camille

The wavelet transform is applied to wave records, containing abnormal waves. The field data are from hurricane Camille. The abnormal waves are readily identified from the wavelet spectrum as an area of high energy, well localized in time and frequency. The wavelet spectrum of abnormal waves, appearing in a group of high waves has maximum value at the time of abnormal wave occurrence and it is concentrated in a narrow frequency range. In contrast the single abnormal wave has wavelet spectrum covering a wide frequency range. The vertical asymmetry of single abnormal wave is reflected in asymmetrical distribution of wavelet transforms. The presence of components with similar phases as a factor for abnormal wave occurrence is studied. Before and after wave crest of asymmetrical abnormal wave, the phases are more dispersive than that during the abnormal crest occurrence.