Validation of WAVEWATCH III Simulations under Hurricanes in Shallow and Deep Water

Abstract:

The validation of surface wave models in shallow water under hurricanes remains a difficult task due to the limited number of observations taken in this regime. In this study we utilize airborne SRA observations of the hurricane wave field under three hurricanes (Hurricane Irene, 2011; Hurricane Ingrid, 2013; and Hurricane Karen, 2013) and use this data to assess the skill of wave simulations from NOAA’s surface wave model WAVEWATCH III. This dataset includes several examples of observed wave spectra in shallow water conditions (<20 m), which allows us to analyze model performance in shallow versus deep water. Our results focus on the sensitivity of the WAVEWATCH III skill to three model factors: the wind forcing, the topography, and the use of a structured grid versus an unstructured coast following grid. By focusing on wave height and dominant wavelength, we conduct statistical analysis to analyze the similarities between the observations and different model configurations. We also compare wave spectra simulated from the models to the observed SRA spectra for further skill assessment. This study is important to increase our confidence in employing the model for shallow water conditions, which contributes to ongoing research efforts to improve prediction of the impact of hurricanes along coastal regions.