Author(s)

R. Neves, P. Leitao, F. Braunschweig, F. Martins, H. Coelho, A. Santos & R. Miranda

Abstract

A main concern in three-dimensional coastal and oceanic modelling is the type of coordinate used for the vertical direction. The appropriate coordinate system should guarantee an adequate resolution in the entire domain and must lead to a stable method with minimal numerical diffusion in order to preserve the vertical structure of the water column. The need for meshes with high aspect ratios of up to 1000:1 makes ocean models highly sensitive to vertical fluxes. A diversity of vertical coordinates has been used in ocean modelling; cartesian, sigma and isopycnic are now widespread. Sigma coordinates are more indicated when topography plays a main role in the flow, while isopycnic coordinates are the most indicated when density is the major

Keywords