Wave observations in the Mahanadi basin (Bay of Bengal) during September 1980

Abstract

The sea state at the location 20 degrees 21'E, 87 degrees 10'N (40 m depth) is described for the periods September 7-11, 1980 (calm) and September 16-18, 1980 (stormy) from the results of spectral analysis and wave by wave analysis of hourly wave records obtained with a shipborne wave recorder on board R V Gaveshani. Wave parameters computed from the two methods are compared. Spectra for the period Sept. 7-11, 1980 reveal two peaks at periods around 16 sec and 8 sec, both owing to 'swell', while the spectra for the period Sept. 16-18, 1980 show a single peak at a period around 8 sec (slowly moving towards lower frequency) owing to 'sea'. The significant wave height, Hmo and the zero crossing period Tm/01 computed from spectral analysis overestimates H1/3 by 8% and underestimates Tz by about 20% respectively