The influence of the spring-neap tidal cycle on currents and density in Burrard Inlet, British Columbia, Canada. The influence of the spring-neap tidal cycle on currents and density in Burrard Inlet, British Columbia, Canada.
Small floods bring outside water through the narrows relatively unmixed which sinks down to depth.
During neap tides currents at depth are generally small, density decreases slowly and turbulent vertical diffusion is believed to be the dominant process at depth. Analysis of vertical diffusion near the bottom at one station during neap tides produces estimates of the vertical eddy diffusivity which are somewhat higher than those from similar studies in other B.C. fjords. Results from the ADCP study reveal the presence of strong vertical velocities downstream of the narrows during large floods, possibly associated with hydraulic jumps. The flow through the narrows at such times is indeed supercritical with respect to the first baroclinic mode.