Modeling surface waves and wind-driven circulation in eastern Lake Ontario during winter storms

Abstract

A spectral wave model coupled to a depth averaged hydrodynamic model was used to simulate the wave and flow conditions in the Kingston Basin of Lake Ontario during winter storm events. The simulations were verified using wave and current profiler data collected over the 2009–10 and 2011–12 winter periods. The model was forced with outputs from the Great Lakes Coastal Forecasting System (GLCFS) as open boundary conditions and winds from a local meteorological station. Wave simulations in the Kingston Basin were better represented using the GLCFS boundary forcing into a model domain of the Kingston Basin; whereas, a model domain that covered all of Lake Ontario yielded a better representation of flows with reasonable wave results. For five storm events that were simulated, approximately 80% of the wave energy outside the Kingston Basin entered the basin after crossing the Duck-Galloo Ridge. Flows throughout the basin showed a complex circulation pattern that is defined by both the forcing and the topographical features including islands, shoals and deep channels. The complex circulation within the basin is composed of several wind-driven gyres which are magnified during storm events. The impact of waves on the circulation patterns at the basin scale is negligible, since shoals are typically too deep (e.g. 20m) relative to the wavelength and period (e.g. 7–10s) to generate large-scale wave-driven flows. In general, the modeling system was successful in reproducing the waves and currents in eastern Lake Ontario and can be used for future engineering-type studies such as offshore wind farm impact assessment.