|On the introduction of refraction effects in a wave prediction model|
Van den Eynde, D.; Monbaliu, J. (1989). On the introduction of refraction effects in a wave prediction model, in: Pichot, G. (Ed.) Progress in Belgian Oceanographic Research 1989: proceedings of the North Sea Symposium held in Ghent, 14 February 1989. pp. 111-128
In: Pichot, G. (Ed.) (1989). Progress in Belgian Oceanographic Research 1989: proceedings of the North Sea Symposium held in Ghent, 14 February 1989. Management Unit of the Mathematical Model of the North Sea and Scheldt Estuary: Brussel. 451 pp., more
The effect of refraction in the Southern North Sea is quite important. The spectral refraction method as introduced by Abernethy and Gilbert (1975) is used to illustrate the considerable distortion of a directional wave spectrum in this area. Numerical wave models including shoaling effects allow for the change in wave speed due to the change in water depth, as well as for a different source function in shallow water to work out the energy transportation equation. They donnot take into account, however, that the direction of swell energy prpagation is influenced by refraction. Therefore a method is proposed to incorporate the directional effects of refraction in the computational scheme. Also, as an alternative method is put forward for swell estimation near the Belgian coast. It is assumed that swell mainly originates from outside the very shallow water area of the southern North Sea, and that the wind sea absorbs little energy from the swell in the region of interest. A good modelling of wind sea and swell in deeper water and a detailed calculation of the refraction effects in shallow water should then give reliable estimates of the low frequency energy in the spectrum.