A Coupled Circulation–Wave Model for Numerical Simulation of Storm Tides and Waves

Abstract

AbstractThe Stevens Institute of Technology Estuarine and Coastal Ocean Model (sECOM) is coupled here with the Mellor–Donelan–Oey (MDO) wave model to simulate coastal flooding due to storm tides and waves. sECOM is the three-dimensional (3D) circulation model used in the New York Harbor Observing and Prediction System (NYHOPS). The MDO wave model is a computationally cost-effective spectral wave model suitable for coupling with 3D circulation models. The coupled sECOM–MDO model takes into account wave–current interactions through wave-enhanced water surface roughness and wind stress, wave–current bottom stress, and depth-dependent wave radiation stress. The model results are compared with existing laboratory measurements and the field data collected in New York–New Jersey (NY–NJ) harbor during Hurricane Sandy. Comparisons between the model results and laboratory measurements demonstrate the capabilities of the model to accurately simulate wave characteristics, wave-induced water elevation, and undertow current. The model results for Hurricane Sandy reveal the successful performance of sECOM–MDO in situations where high waves and storm tides coexist. The results indicate that the temporal maximum wave setup in NY–NJ harbor was 0.26 m. On the other hand, the contribution of wave setup to the peak storm tide was 0.13 m, a contribution of only 3.8%. It is found that the inclusion of wave radiation stress and wave-enhanced bottom friction in the circulation model can reduce the errors in the calculated storm tides. At the Battery (New York), for example, the root-mean-square error reduced from 0.17 to 0.12 m.