To Couple or Not to Couple: optimization for oceanographic - wave model synchronization

John C. Warner
US Geological Survey, Coastal and Marine Geology Program, Woods Hole, MA, USA


Prediction of nearshore processes is important for coastal circulation, water quality, shoreline change, and recreational safety. We have enhanced the capabilities of ROMS to include many new features for nearshore applications, including wetting/drying, morphology, nearshore radiation stress forcings, surface roller model, and two-way coupling to the wave model SWAN. The coupling is performed using shared libraries from the Model Coupling Toolkit. The two-way coupling allows wave propagation to respond to flow from the circulation model and bathymetric changes from the sediment-transport model. In return the mean circulation responds to wave transformations and the sediment transport responds to the wave-orbital motions. Here we focus primarily on the implications for model coupling, describe the methodology, and examine the interactions by varying the synchronization levels. Several simple test cases demonstrate the importance of the wave-current interactions.