Dependence of Currents and Density on the Spring–Neap Cycle and the Diurnal Inequality in Burrard Inlet, British Columbia: Simulations and Observations

Abstract

Observations of the circulation in a hole near a constriction in Burrard Inlet are simulated using a two-dimensional (i.e., laterally integrated) numerical model. The model uses a level-2 version of the Mellor?Yamada turbulence closure scheme. During spring tides, when mixing is at its most intense, the density in the hole decreases (increases) during the large (small) floods, and there is an up-inlet current pulse into the hole during each flood regardless of the flood's strength. During the large floods in particular, the simulation is significantly improved if the explicit influence of horizontal spatial variations on the production of turbulent kinetic energy is taken into account. During neap tides the simulated density is much less variable, and the currents in the hole are much weaker, in agreement with the observations. The model differs from the observations in that the simulated current pulses are significantly weaker than the observed pulses, possibly because the cross-channel averages computed by the model may not be a good estimate of the observed currents.