Numerical Modeling of the Circulation of Wind-Driven Sediment Plumes In Large Lakes

Abstract

Strong winds blowing down the axis of southwestern Lake Superior in the springtime can produce a wind-driven sediment plume. The plume has coastal currents in the same direction as the wind stress and a balancing return flow that is driven by a pressure gradient into the open lake. Analytical developments suggest the return flow volume is determined by the wind stress on the channel and basin morphology. An idealized, three-dimensional model was developed in MITgcm to study this relationship. We find the modeled volume transport to be on the same order of magnitude as the analytical approach and to be dependent on wind stress, basin depth, and basin width. Realistic, three-dimensional models of Lake Superior and Lake Huron are developed to understand the relationship between wind stress on the lakes and the circulation driving wind-driven sediment plumes in them. We find that analytical estimates of volume transport are on the same order of magnitude as the realistic models and that the volume transport is linearly related to the wind stress.