High waves measured during tropical cyclones in the coastal waters of India

Abstract

The high waves in the ocean generated by tropical cyclones cause ship accidents and damage to offshore structures. This study examines the characteristics of high waves from the measured half-hourly directional wave data using waverider buoys during five cyclones in the coastal waters of India at 15-50 m water depth. The highest wave height measured in different cyclones varied from 8.1 to 13.5 m. At all locations, the influence of the cyclone on wave heights lasted for a short period only (3 days). The average increase in wave height with time due to the influence of cyclones is ~0.17 m/h. The maximum crest height and the maximum height of the extreme waves are 0.90 and 1.75 times the significant wave height, respectively. When the cyclone reaches its peak intensity, the highest significant wave heights associated with Phailin and Kyarr are found to be in the right front and right back quadrants relative to the cyclone heading, whereas, for Thane, Hudhud and Tauktae, they are located in the right back quadrant. The significant wave height obtained from the time series is smaller than that obtained from the corresponding wave spectrum.