The representation of boundary currents in a finite element shallow water model

TL;DR

This paper investigates how different modeling choices affect the simulation of boundary currents in a finite element shallow-water model, emphasizing the benefits of finite element methods for complex coastlines and boundary conditions.

Contribution

It demonstrates the advantages of finite element discretization in accurately representing boundary currents and coastlines compared to traditional methods.

Findings

Finite element methods offer greater flexibility for complex geometries.

Grid refinement improves the accuracy of boundary current separation.

Boundary conditions significantly influence current simulation.

Abstract

We evaluate the influence of local resolution, eddy viscosity, coastline structure, and boundary conditions on the numerical representation of boundary currents in a finite element shallow-water model. The use of finite element discretization methods offers a higher flexibility compared to finite difference and finite volume methods, that are mainly used in previous publications. This is true for the geometry of the coast lines and for the realization of boundary conditions. For our investigations we simulate steady separation of western boundary currents from idealized and realistic coast lines. The use of grid refinement allows a detailed investigation of boundary separation at reasonable numerical cost.