Influence of wave setup and tide-surge interaction on storm surges in the Bay of Bengal

This study employs a coupled wave-hydrodynamic model to simulate storm surges and waves from 15 tropical cyclones (TCs) along the east coast of India and the head Bay of Bengal (BoB) from 2010 to 2020, selected based on available tide-gauge data. By maintaining uniform model settings-such as domain, mesh, bathymetry, and atmospheric forcing-across all simulations, we offer a consistent framework for evaluating tide-surge-wave interactions, contrasting with previous studies that focused on individual TCs with varied model settings. Our findings reveal that wave setup can play a significant role, contributing up to 86% to the tide-removed water level amplitude for intense TCs. This contribution varies according to TC intensity, tidal phase, bathymetry, and the location of maximum winds. Tide-surge interaction proves crucial, accounting for up to 31% of the contribution, only for TCs making landfall in the head BoB region having shallow bathymetry and curved pockets of the BoB coastline featuring shallow regions. This work enhances our understanding of the complex storm surge dynamics, providing a more comprehensive knowledge for future studies and mitigation strategies in vulnerable coastal regions of the BoB.