Wind field and model resolution optimization and testing source terms for the prediction of cyclone induced waves in the Bay of Bengal

The present study examines the impact of wind data resolution on wave climate prediction using the wind-wave model, WAM using different spatial resolutions of wind data such as 1/5 degrees, 1/10 degrees, 1/20 degrees, and 1/40 degrees, obtained from the Weather Research and Forecasting (WRF) model. It focuses on the prediction of extreme waves caused by three cyclones (Phailin, Hudhud, and Vardah) that hit the Bay of Bengal region of the North Indian Ocean in 2013, 2014, and 2016, respectively. These cyclones had a significant impact on the east coast of India and have generated significant wave height (Hs) of more than 10 m. To accurately predict these high-impact waves, it is necessary to have suitable wind resolution and a stable wave model grid resolution. We also investigate the effect of different spatial resolutions (1/5 degrees, 1/10 degrees, 1/20 degrees, and 1/40 degrees) on wave prediction. There is no significant difference in Hs prediction accuracy for wind data and wave model resolutions better than 1/10 degrees. Additionally, the WAM model is tested with Ardhuin's input and dissipation source terms included in the model which doubles the source terms computational time required by the model although providing better predictions in the nearshore locations. An optimal model resolution of 1/10 degrees, along with Ardhuin's source terms, is recommended for better wave prediction.