Swells Modulated TCs Waves in the Bay of Bengal

Tropical cyclones (TCs) waves have a significant impact on offshore and coastal engineering, beach erosion and flooding in coastal areas. An attempt is made to study the modulation effects of the swells from Southern Indian Ocean on TC waves in Bay of Bengal (BoB). The third generation ocean wave model, SWAN (Simulating Waves Nearshore) is implemented and validated to simulate significant wave heights (SWH) and mean wave period (MWP) during four TCs in 2013. Simulations were carried out by three different model domains for analyzing the swells modulation effects. It was discovered that swells from the Southern Indian Ocean significantly influence the wave climate in the Bay of Bengal during tropical cyclones. Along the western and eastern coasts of the Bay of Bengal, the contribution of swells to tropical cyclone wave heights is substantial, owing to the shelter provided by topographical features such as islands and reefs. In the inlet of the BoB, TC waves are also modulated by swells. However, near the centers of TCs and in the middle of the BoB, the modulating effects of swells are weak or even negligible.