The inverse finite element ocean model (IFEOM) is intended for estimatesof ocean circulation by assimilating hydrographic data.It is based on a steady-state version of the finite element ocean generalcirculation model FEOM (Danilov et al., 2004). It solves steady momentumequations for velocity and sea surface height field, and treats theadvective-diffusive tracer balance as a soft constraint.IFEOM seeks for density field, wind stress, and velocities at openboundaries which give minimum to its objective function. The latterpenalizes residuals in the tracer equation, deviations of modelvariables from data available and also misfit between diagnosed deeppressure gradient and the pressure gradient of the forward run of FEOM.The deep pressure gradient constraint is applied below 2000 m andturns to be crucial in keeping the integral properties ofthe diagnosed circulation consistent. The physicalmotivation behind this constraint is that the deep ocean circulationis relatively stable and should not be influenced much by assimilation.The model and its adjoint are presented. They were applied to estimatethe circulation of the North Atlantic byassimilating several climatological datasets.
Helmholtz Research Programs > MARCOPOLI (2004-2008) > German community ocean model