Observed Seasonal Variation Of Wave Power From Moored Buoy Measurements - A Case Study On The East Coast of India

Abstract

The wave climate in Indian waters is strongly influenced by the seasonal variation. Accurate wave height assessment is crucial for wave power computation which is proportional to square of the significant wave height. Any error in wave height is magnified in the wave power estimation. Wave models tend to predict medium range wave activity to a desired degree. Insufficient wind, bathymetry and grid resolutions, model physics parameterizations also account for the errors. Wave models generally employ linearization approximations to reduce the huge computational burden which tends to show higher deviations from measurements during high intensity cyclones and peak monsoonal wave conditions. Globally, due to climate change effects, cyclones are occurring more frequently with high intensities. Hence, wave models have to be validated with measurements before they are used for wave power assessment, or to use model derived parameters in the design of wave energy converters in order to withstand the high intensity cyclones.  In this study, the seasonal variation of wave power on the East coast of India, off Machilipattinam has been evaluated from a year-long in-situ observations from National Institute of Ocean Technology moored buoy deployed in deep waters. The variation of wave power during the cyclones captured by the buoy has also been discussed.