Wave spectra and statistics off Godavari during September-October 1980

Abstract

An analysis of sixty one wave records collected using a shipborne wave recorder (SBWR) showed wide variations in spectral shape. Some of the spectra are relatively narrow and peaked, some are proad with small peaks and some have multiple peaks. Half spectral peak bandwidth (BW) gives a more meaningful value to explain the spectral shape compared to spectral width parameter, ( Es from spectra and Ez from zero-upcrossing method) and spectral peakedness factor (Qp). The average zero-upcrossing period, Tz varies from 8.1 to 12.9 sec and compares well with the significant wave period, Ts. Tz and Ts are found to be better estimates compared to other average periods. During the period of observation (September -October) since calm weather prevailed (storms were absent in the Bay of Bengal) the significant wave heights are centred around 1 m. Es and Ez vary between 0.53 and 0.82 and between 0.52 and 0.80 respectively. BW varies from 0.02 to 0.07. The primary peaks are observed between 8 and 17 sec. The present study fairly describes the average condition of the sea surface ID the absence of any storm.