Variations in Swells along Eastern Arabian Sea during the Summer Monsoon

Glejin Johnson,Premanand Pednekar,K. Ashok Kumar,Rajamanickam Gowthaman,V. Sanil Kumar,Jai Singh,Sajiv Philip Chempalayil,G. Udhaba Dora

doi:10.4236/ojms.2012.22006

Abstract

A study was carried out to find the variation in wave characteristics along the eastern Arabian Sea and the influence of swells in the nearshore waves at 3 locations during summer monsoon in 2010. Percentage of swells in the measured waves was 75% to 79% at the locations with higher percentage of swells in the northern portion of Arabian Sea com-pared to that at the southern side. The significant wave height up to 4.7 m and maximum wave height up to 7.4 m was observed. The wave height was increasing from south to north with the average significant wave height at the northern location 20% more than that at the southern location due to the increase in the swell height. Waves having spectral peak period less than 6 s were not present during the summer monsoon period. There was no change in the average value of wave statistical parameters for data collected at 1/2, 3, 6, 12 and 24 h interval.

Highlights

Information on swells is required for navigation and operation of marine facilities
The wave height was increasing from south to north with the average significant wave height at the northern location 20% more than that at the southern location due to the increase in the swell height
The wave height was increasing from south to north with the average Hm0 at the northern location 20% more than that at the southern location and the increase was mainly due to the increase in the swell height

Summary

Introduction

Information on swells is required for navigation and operation of marine facilities. When seas and swells are present the wave energy spectrum will be multi-peaked with peaks corresponding to seas and swells. Along the Indian coast, about 60% of the wave spectra observed was multi-peaked and they were mainly single peaked when the significant wave height (Hm0) was more than 2 m [1]. The multi-peaked spectra observed were mainly swell dominated with average value of the ratio of the two spectral peaks around 0.6 and the average value of the difference between peak frequencies around 0.09 Hz. Waves in shallow water location off the west coast of India during the onset of summer monsoon [2] and in shallow water location in the north Indian Ocean during the summer monsoon [3] were mainly swells arriving from south and south-west direction

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Results

Conclusion