Application of advanced data assimilation methods for the initialisation of storm surge models

A sequential data assimilation technique (utilising a reduced-rank square-root filter) has been incorporated into the complete non-linear equations of a hydrodynamical module of a standard two dimensional hydrodynamic modelling tool. The deterministic model output is corrected using the available data and the best model initial conditions are generated. The deterministic model is then used to generate the water level forecast. A description of the general technique that is applied and its adaptation to this particular problem are provided. The application to a real storm that occurred during February 1993 in the North sea is presented.