Simulating ice–wave interactions in the Laurentian Great Lakes using a fully coupled hydrodynamic–ice–wave model

Hydrodynamic modeling in cold climate regions necessitates more sophisticated approaches that accurately simulate ice–wave interactions. Traditional models often overlook the complex coupling mechanisms between ice and ocean waves, especially the two-way processes where ice attenuates wave energy and waves break ice floes. This oversight can also intensify modeling challenges in coastal areas, including large lakes, where ice–wave interactions influence storm surges, high waves, and coastal erosion. To address this gap, this paper introduces an enhanced modeling approach that integrates both ice-induced wave attenuation and wave-induced ice breakage. To implement these processes, the Finite-Volume Community Ocean Model (FVCOM) is coupled with an unstructured-grid wave model (SWAN) and the unstructured-grid version of the Los Alamos Sea Ice Model (UG-CICE) to form the FVCOM–SWAVE–UG-CICE framework. Using this fully coupled model, simulations were conducted for the Great Lakes. Results of the modeled ice concentration, ice thickness, and significant wave heights were reported and validated against observational data from the U.S. National Ice Center (NIC) and in-situ under-ice measurements. To further study the coupling effects, results of the proposed model were also compared with those from no coupling and one-way coupling (focusing only on ice-induced wave attenuation) models. Comparative analyses demonstrated significant improvements in the predicted ice concentration with the proposed fully coupled model. These findings reveal the importance of incorporating ice–wave interactions in accurately predicting ice cover dynamics in freshwater systems.