A Validated Coupled Three-Dimensional Hydrodynamic and Wave Model for Water Levels and Wind Waves in the Western North Atlantic Ocean

Abstract

Accurate prediction of the coastal ocean requires models that capture dominant barotropic drivers, resolve baroclinic processes, and account for wind-waves. This study evaluates the performance of a high-resolution coupled three-dimensional hydrodynamic (SCHISM) and spectral wave (WWM III) model for simulating water levels and wave characteristics in the western North Atlantic Ocean. The model performance is evaluated for different wave parameterization methods, and the contribution of waves to water levels is quantified. Comparisons with in-situ measurements show that the coupled model reproduces tidal constituents, non-tidal components, and total water levels robustly along the U.S. East and Gulf of Mexico Coasts. Simulations using three different wave-physics parameterizations in the wave model show that each performs well for specific wave characteristics and locations; however, no single parameterization is optimal across the entire basin. Finally, the results show that including waves increases modeled water-level accuracy by about 3% on average across all study sites, though the improvement varies regionally. The greatest increases in accuracy, approximately 10% on average, occur at sites in the Gulf of Mexico.