Evaluation of Site Specific Constants for Sustained and Cyclonic Wave Energy Assessment in Central Arabian Sea from a Decade of Moored Buoy Measurements and Model Comparison

Wave energy is the cleanest perennial source of energy which is site-specific and highly dynamic in nature. Wave power characteristics in the central Arabian Sea with swell dominant conditions are accurately assessed from a decade of deep water moored buoy measurements. The ECMWF ERA5 global wave model deviations are estimated by comparing with observations for seven common bulk wave parameters. The monthly variation of correlation and error statistics based on 10 years data is analyzed. Wave parameter ratios between the observations and model are derived for each month based on the longterm statistics for seven common parameters. The wave period of chosen numerical model is multiplied by a 'constant' to arrive at the equivalent single-peaked wave energy spectrum to that of the measured spectrum of mixed seas. This constant or wave energy period ratio, is site specific and varies based on the theoretical spectrum used in the model and spectral shape. Hence, it is very important to use the correct constants pertaining to Indian waters for the accurate assessment of wave power in Indian seas. The site specific wave energy period ratios, with respect to different model periods and other observed periods based on the observed interannual statistics are derived. This location is under the influence of monsoons, swells coming from the Southern Indian Ocean as well as cyclones. The seasonal variability of wave characteristics controls the sustained wave power. The maximum power depends on monsoon or intense cyclones that are on the verge of increase due to climate change. The interannual variability of maximum and sustained wave power are quantified for each month, which aids in the design criteria of wave energy converters. Nine predominant cyclones that showed response at the buoy location over the decade are analysed for peak wave power. This study helps in the validation of numerical model as well as in the transformation of deep water wave power to the coastal waters of a given depth using modification coefficient as an approximate estimate.