Using sea-level data to constrain a finite-element primitive-equation ocean model with a local SEIK filter

Abstract

Inspired by the pioneering work of Christian Le Provost on finite element ocean modeling, a new ocean circulation model was developed over the last few years. It applies a surface triangulation and finite elements for an accurate description of coasts and bathymetry and their steering effect on the ocean circulation. A novel feature is the mesh design, which allows a vertical structure in geopotential (z) coordinates without loss of flexibility and avoids pressure gradient errors everywhere except for the lowest layer of abyssal ocean. The model is combined with sea-level measurements and data assimilation, another major research topic of Christian Le Provost. We apply the SEIK filter that was developed in Grenoble while Christian was teaching there. The addition of a local analysis scheme improves the filter performance, first of all, in its variance estimates and also in its mean solution. © Springer-Verlag 2006.