A two‐dimensional numerical model which simulates the temperature, salinity and velocity fields in knight inlet, British Columbia

Abstract

A two‐dimensional laterally integrated model of Knight Inlet, British Columbia is used to simulate the time‐varying temperature, salinity and velocity fields. The model includes the influence of the wind, tides, solar heating and freshwater inflow. The level 2.5 turbulent closure scheme of Mellor and Yamada is used to parametrize the diffusion terms in the model. In this paper, two turbulent kinetic energy boundary conditions at the air‐water interface are compared. One boundary condition is for an enhanced surface turbulent layer due to the flux of wind energy while the other is based on the Law of the Wall approach. The model is compared to data collected in the summer of 1989 from four moored vertical arrays. Salinity, temperature, horizontal current velocity and wind velocity were measured for about thirty days. Measurements were made throughout the water column so that the thin surface layer and deep water flows could be resolved. A moored array near the mouth of the inlet was used to provide open boundary data for the model, while the remaining data were compared to the simulated data. The modelled salinity fields were very realistic particularly when the enhanced turbulent surface layer boundary condition was used. The temperature fields were well modelled as long as the surface temperature was prescribed. The simulated velocities were very similar to those produced by a numerical model which simulated density (with the pressure effect removed) directly, instead of solving for temperature and salinity and then determining density via an equation of state.