Hindcasting coastal sea levels in Morecambe Bay

A method of variational data assimilation (by means of an adjoint model) is used to improve the boundary conditions for a high resolution depth-averag ed two dimensional non-linear hydrodynamic model of Morecambe Bay. The mode lled region contains a large inter-tidal area and has an unusually high tid al range. The assimilation procedure is robust and effective in reducing mo del error. This system performs considerably better than the previous simpl e method used for assimilating data into the same numerical model. Height e rrors as low as 10 cm (root mean square) can be achieved. (C) 2001 Academic Press.