Sensitivity analysis of surface wave hindcasts for the Indian Ocean

Abstract

A sensitivity analysis of wave hindcast in the Indian Ocean was carried out using measured wave data at 12 locations in the North Indian Ocean (NIO). The numerical model MIKE21 Spectral Wave (SW) is used for hindcasting the data for the year 2017. The model forced by wind data from European Centre for Medium-Range Weather Forecasts (ECMWF) operational archives at 6 hours temporal resolution and 0.10 spatial resolution. The present analysis aims to assess the model performance with different domain configuration. Two domain extensions with Open and closed boundary scenarios are evaluated with previous wave atlas published by National Institute of Ocean Technology (NIOT), Chennai during 2014 (Here after Atlas v.1) and measured wave data. Significant wave height (Hs) and wave period parameters were used to compare with the wave hindcasts and twelve in-situ observations-Six deep water and six shallow water locations in Arabian Sea (AS) and Bay of Bengal (BoB) during 2017. The results from Atlas v.1 taken as a hind cast reference for the comparisons. The Hs simulation capability is very well in all domains since the NIO Hs is largely depends up on prevailing seasonal reversing wind regime. But wave period parameters obtained from different domain configurations have significant difference due to the influence of Southern Ocean swells over NIO wave climate. Considering the results, the domain with 60S southern extension and open boundary have better match with observation