Résumé
The influence of mantle compressibility and warping of the ocean surface on dynamical models of the geoid has been investigated. Topography and geoid kernels show that compressibility modifies the mantle-flow pattern and hence the geoid, whereas the deflection of the oceanic surface amplifies the geoid signal without affecting the global flow. The combined influence of these two effects is significant and depends on the viscosity profile in the mantle. Comparisons with incompressible dynamical geoids show that including the effects of compressibility and ocean warping improves the fit to the observed geoid. Thus these effects must not be neglected in dynamical computations of the geoid.