Field measurements and non-linear prediction of wave celerity in the surf zone

A good prediction of wave celerity in the surf zone is essential for wave propagation modelling in the nearshore. This paper is devoted to a study of wave celerity based on the analysis of data collected during the ECORS 2008 field experiment that took place at Truc Vert Beach, SW France. Here we analyze and quantify the effects of non-linearities and evaluate the predictive ability of several non-linear celerity predictors for high-energy wave conditions. The asymptotic behaviour of the different models for high values of the non-linearity parameter is investigated. Besides, comparisons with data show that the classic bore model is inappropriate for describing wave dynamics when approaching the swash zone. The influence of very low frequency pulsations of the wave-induced circulation on wave celerity is also discussed.