Enhancing Storm Wave Predictions in the Gulf of Mexico: A Study on Wind Drag Parameterization in WAVEWATCH III

This study focuses on the significance of wind input source terms and their impact on wave generation in the wave model, WAVEWATCH III. Storm wave modeling capabilities were assessed with three different wind source term schemes ST4, ST6, and a new implementation ST6-IWD in a wave model to study Hurricane Ida (2021). A nested modeling approach was employed with high-resolution atmospheric wind forcing products obtained from the NOAA and the ECMWF. The model results were compared to field observations from NDBC buoys. One key finding indicates that the ST4 physical scheme is not necessarily suitable for modeling waves under extreme wind conditions. The ST6 and ST6-IWD schemes performed well for the hurricane scenario and the wave parameters obtained from these two sets of simulations were in good agreement with the observed values. The wind source term derived in the ST6 scheme holds good for wind speeds up to 50 m/s, whereas the drag method in ST6-IWD could remain stable up to ~113 m/s wind speeds. Therefore, this study recommends the ST6-IWD scheme, as it is suitable for more extreme hurricane wind conditions. It was also identified that the ST6-IWD method better estimates the peak wave periods and peak directions for Ida’s conditions.