Solution convergence of flow over steep topography in a numerical model of canyon upwelling

Abstract

The convergence as resolution is increased is examined for a numerical model simulation of upwelling over a continental shelf canyon. A series of idealized one‐ and two‐dimensional models are used to plot the dependence of bottom Ekman layer velocity structure and transport on model resolution. Using these results as a guide, a bottom Ekman layer‐resolving three‐dimensional numerical model is constructed. This model is used to simulate a laboratory model of canyon upwelling. Alongshore velocity, volume of fluid upwelled through the canyon onto the shelf, and change in depth of the canyon water are examined at three grid resolutions. Numerical model particle trajectories are compared with a laboratory model of canyon upwelling to validate the model. The results suggest that current computational cluster power is sufficient to accurately simulate all aspects of upwelling in a steep canyon with the exception of flow separation from the canyon wall.