Summer Circulation in the Kingston Basin, Lake Ontario

During the summers of 1986 and 1987 a network of current meter moorings, meteorological buoys, and satellite drifters was deployed by National Water Research Institute (NWRI) to examine the circulation in the Kingston basin and St. Lawrence River outflow area. Power density spectra were computed along vector components and clockwise and counterclockwise components. Coherence and phase were computed between surface and bottom currents at the same mooring, and between current and wind stress. The analysis reveals a varied response of currents to wind stress throughout the basin and indicates the existence of complicated hydraulic and wind-induced circulation patterns. The principal axes and mean direction of the measured currents shows that the flow is strongly influenced by bottom topography. The numerous islands in the Kingston basin affect the circulation. The record mean flow along the north side of Amherst Island is weak; however, the currents exhibit high variability in response to barotropic pressure gradients induced by wind-driven water level set-up, with the flow around Amherst Island being 180° out of phase with the wind. During the summer months the flow in the Kingston basin is stratified, resulting in two-layer flow at the boundary between the basin and Lake Ontario. The mean currents in the epilimnion move landward toward the St. Lawrence River mouth while the mean currents in the hypolimnion move lakeward toward Lake Ontario through three deep channels.