Tidal spectroscopy of the English Channel with a numerical model.

Abstract

The possibility of reproducing the complexity of tides in shallow water areas with a classical finite difference numerical model is examined. This hydrodynamic model is two dimensional but incorporates topography, non-linear advection and quadratic bottom friction. Particular care is taken to prescribe sea surface elevations at the open boundaries. A one month simulation of 'real' tides is run with a simplified spectrum restricted to only 24 constituents, corresponding to the nine main astronomical tides and their non-linear significant interactions. The results are analysed by spectral decomposition (elevations and vertically integrated currents) and compared with observational data from the tide guages and current meters, and with other solutions produced in the literature. Suggests that a second order scheme must be implemented. Non-linear effects are satisfactorily reproduced but damping remains a problem. (from author's abstract)