Variations in wind wave parameters measured in the coastal waters of north-eastern Bay of Bengal

Characteristics of the wind waves measured in the coastal waters of the northeastern Bay of Bengal are examined for 4 years. A comparison of the energy wave period (T_e) with different wave periods shows that the average wave period (T_m–1,1), significant wave period (T_1/3), and integral period (T_i) are closer to T_e. A maximum wave height of 5.5 m is observed, and the most typical values for the wave period range between 4 and 6.5 s. The steepness of the highest wave is 0.058. In the coastal waters, the values of the peak wave period (T_p) indicate a swell dominance in the monsoon. Short-period waves (T_p < 6 s) are relatively higher in 2015 and the long-period waves (T_p > 8 s) in 2013 and the changes are due to the variations in monsoon. A large number of long-period waves is observed during the northeast monsoon. Thirty-seven freak wave events occurred, and the presence of freak waves is higher in the monsoon. Interannual variations in the mean of T_avg are up to 5% and that of the 90-percentile of the average wavelength (λ_Tavg) is up to 10%. The annual mean wave power is 5 kW/m and annually during 25% of the time, the wave power is more than 7 kW/m.