The temporal evolution of baroclinic basin-scale waves in a rotating circular basin

The temporal evolution of baroclinic basin-scale waves in a rotating circular basin following an initial forcing event is investigated using a laboratory study. Experiments conducted in the circular domain containing a two-layer fluid with a flat bottom and vertical sidewalls demonstrate that the response is essentially linear with frictional effects at the boundaries steadily dissipating wave energy. Experiments conducted in the same configuration but with the addition of simple topographic features, either a radially protruding cape or a bathymetric ridge, exhibit wave/topography interactions that result in the formation of an eddy field and an offshore flow, respectively. The rate of wave decay, as well as the amount of horizontal mixing occurring within the basin, is significantly enhanced by such interactions. The results of this study are then considered in terms of their implications for the baroclinic basin-scale wave energy pathways in large stratified lakes influenced by the Earth's rotation.