The generation and propagation of internal waves in Nootka Sound

Abstract

[author abstract] The inlets of Nootka Sound, British Columbia provide a favourable area to study internal wave generation and propagation due to their varying bottom topography, the presence of sills and the occurrence of semi-diurnal tides. For this study, current velocity profiles were collected using a ship mounted Acoustic Doppler Current Profiler (ADCP), and were complemented with CTD profiles from an UnderwayCTD (UCTD).Three mechanisms of internal wave generation were proposed, with one likely source of generation being due to the release of trapped internal waves at the head of the inlet with changing tidal phase from flood to ebb. There was also evidence for the excitation of baroclinic flow in the inlet. The importance of internal waves stems from their ability to transfer energy more efficiently than surface waves. This aids deep water mixing, which originates from turbulence at the sill and extends into the basin.