Field observations of irregular wave transformation in the surf zone

Wave transformation on a transect crossing the surf zone of a fine grained, gently sloping barred beach has been further investigated with data from a 5-element coherent bottom-mounted pressure sensor line. In particular, field evidence is given for phenomena such as construction of merging shocks occurring on a short distance (several wave lengths) and deeply changing the wave field. The initially Rayleigh height distributions in 9-m depth were observed to be modified by shoaling and breaking into new distributions which present surplus at the medium waves and deficits at the lowest waves (compared with the Rayleigh wave distribution). Such phenomena are of great interest for random wave shoaling and breaking models.