Long-Term Estimation of Wave Climate Variability in the Western Bay of Bengal

The ocean plays a major role in climate change, and its impact has an extreme effect on the process of coastal and other activities around the globe. The comprehensive analysis of long-term wave climate is carried out at selected locations in the western Bay of Bengal (BoB), by observing the distribution of significant wave height (SWH) using monthly averaged satellite and WAM model for 20 years (1996-2015). The data used in this study were compared with two in situ buoy observations obtained from the National Institute of Ocean Technology (NIOT), Chennai, India. The satellite and wave model (WAM) data show a good correlation with both in situ buoy observations. The probability distribution functions indicated a significant increase in the higher range of SWH during the recent decade. The analysis of 20-year SWH indicates a positive trend with significant annual and semiannual periodicities. The northwestern bay depicts higher energy in the annual cycle, whereas the southwestern bay exhibits equal contributions from annual and semiannual cycles. The study also reveals that the increasing trends in local SWH in the western BOB are modified due to the number of tropical cyclones as well as the migrating swells generated in the southern Indian Ocean.