The semi‐diurnal tide in Hudson strait as a resonant channel oscillation

Abstract

Abstract Tidal studies have shown that there exists a resonance of the semi‐diurnal tide in the Hudson Bay‐Hudson Strait system. The resonant response is particularly strong within Hudson Strait and Ungava Bay. It is shown here that the semi‐diurnal tide in Hudson Strait has characteristics that are similar to those of a half‐wavelength open channel resonance. A simple analytical model is developed to account for the salient aspects of the semi‐diurnal response in the strait. Non‐dimensional parameters that govern the response are identified and evaluated based on the physical dimensions of the region and results from a numerical tidal model. Taking account of the mechanical impedance presented to the channel by Hudson Bay, the results suggest that a channel mode is resonant near semi‐diurnal periodicities, in general agreement with observations and more complex tidal models of the region. The possibility that Ungava Bay may have a separate quarter‐wavelength resonance driven at the entrance to the continental shelf is also briefly explored.