Eigenfunctions in the Galerkin method of tidal current modelling

Empirical orthogonal function (EOF) analysis of acoustic doppler current profiler data is used to provide a physical justification for the use of eigenfunctions derived from simple vertical eddy viscosity profiles in the Galerkin method of three-dimensional, tidal current modelling in a homogenous sea region. A good fit of EOF modes to eigenfunctions derived from a simple parameterized vertical eddy viscosity profile is obtained. An empirical determination of the most appropriate expression for the temporal dependence of such vertical eddy viscosity profiles is also given.