Spectral wave characteristics in the coastal waters of the central west coast of India during tropical cyclone Kyarr

Abstract

The study presents the assessment of spectral wave conditions in the coastal waters of the central west coast of India based on data from waverider buoys at two locations during the passage of tropical cyclone Kyarr. Due to the impact of the tropical cyclone, at 15 m water depth, the annual maximum significant wave height of 5.1 m occurred in October for the first time in the last 42 years. Though the cyclone track was close to the location Vengurla, maximum energy waves are observed at Karwar, a location ~ 125 km south of Vengurla due to the super-imposition of the cyclonic waves with the comparatively high energy long-period swells existing at Karwar. The high-frequency slope of the wave spectra becomes steep due to cyclone with a value close to − 4. Wave spectrum during cyclones is better represented by the JONSWAP spectrum with modified parameters, and the maximum value of peak enhancement factor observed during the cyclone period agrees with the mean value (3.3) suggested by the JONSWAP study. The wave heights obtained from the numerical model are also compared with the measured values. The spatial variation in waves has been investigated using the ERA5 reanalysis data.