Global tide - FES2004

The last version of the FES (Finite Element Solution) tide model is called FES2004. It is a fully revised version of the global hydrodynamic tide solutions initiated by the works of Christian Le Provost in the early nineties. It has been developed, implemented and validated by the LEGOS and CLS.
This new version is based on the resolution of the tidal barotropic equations on a new global finite element grid (~1 million nodes) which leads to solutions independent of in situ and remote-sensing data (no open boundary conditions and no data assimilation).
A new original high resolution bathymetry was used and ice on polar regions was taken into account. The accuracy of these 'free' solutions was improved by assimilating tide gauge and altimetry data (T/P and ERS-2) through a revised representer assimilation method.
15 tidal constituents are distributed on 1/8° grids (amplitude and phase). 28 others constituents are taken into account by the means of a specific admittance method and a long period wave computation. New tide loading effects were also computed (Olivier Francis). A new prediction algorithm is distributed within the FES2004 package to provide tidal heights at any location of the world ocean.

Main improvements between FES99 and FES2004

The main improvements are:

  • refinement of the finite element mesh (~300.000 points to ~1.000.000 points)
  • revised assimilation scheme
  • new bathymetry
  • new coastlines
  • take into account ice coverage in polar areas
  • new altimetric data assimilated (T/P and ERS-2)
  • new tide gauge data assimilated
  • new hydrodynamic wave included : M4 (great benefits for coastal areas)
  • the S1 tide from Richard Ray is now included in FES2004
  • four long hydrodynamic period waves are added: Mf, Mm, Mtm, Msqm (and removed from the Cartwright long period tide algorithm...)
  • the prediction code was fully revised and optimized to take into account new waves and loading effects (C and Fortran routine)
  • the gridded resolution of the distributed package is now 1/8° instead of 1/4°