Improving Wave Model Simulation in the Bay of Bengal: A Nested SWAN Model Calibration Study

This study establishes a nested model from the Indian Ocean to the Bay of Bengal based on the third-generation numerical wave model SWAN. The model is calibrated based on the driving wind field, input source function, and physical parameters. A full year of wave simulation is performed to verify the model. The findings reveal a strong correlation between the wind field data from ERA5 and CFSv2 with the satellite altimeter wind speed data, with ERA5 demonstrating better performance. When employing the same input source function, the two wind fields show significant differences in their error statistics. The ST6 source function improves the modeling of wind input and swell dissipation compared to the KOMEN source function, which is more suitable for the simulation of BOB waves. The model achieves significant simulation accuracy when the calibrated ST6 parameter values are combined with the ERA5 wind field.