Hydrodynamic and Transport Model for the Lake Michigan Coast around Milwaukee

The nested models simulate flow and transport in the Lake Michigan coast around Milwaukee, have alongshore and cross-shore dimensions of 45.5 km and 12 km, and maximum depth of 25 m. The alignment of the open lake boundary is important because the boundary condition formulation may introduce perturbations when oblique velocities cross the boundary. Aligning the open boundary parallel to an isobath caused negligible perturbations. The models yielded a good reproduction of measured currents and an adequate reproduction of vertical temperature profiles. The alongshore currents are approximately ten times larger than the cross-shore currents. Local wind direction is an insufficient predictor of flow direction. The lake circulation pattern sometimes causes the flow near Milwaukee to split into counter-rotating eddies. Preliminary results of the transport model reveal that along-shore transport dominates over cross-shore transport and a complex transport pattern inside the Milwaukee Outer Harbor when the currents through the breakwater gaps change direction.