Momentum balance under breaking waves: Closure to discussion by T.E. Baldock of ‘Laboratory investigation of pressure gradients induced by plunging breakers’

This paper replies to observations put forward by Prof. T.E. Baldock [Baldock, T.E., 2012. Discussion of “Laboratory investigation of pressure gradients induced by plunging breakers”, by Pedrozo-Acuña et al. Coastal Engineering, Vol. 66, August 2012, pages 1–2] regarding a laboratory investigation of pressure gradients induced by plunging breakers. Firstly, we focused on clarifying the inconsistencies and present the revised figures which do not change the conclusions reached in the study. Moreover, in order to confirm and extend the derived conclusions in the aforementioned investigation, we conduct a numerical study of momentum balance in the surf zone for different types of breaking. The analysis incorporates results from a well validated RANS model, which enables the assessment of the fluid acceleration and pressure gradients. It is demonstrated that the type of wave breaking controls the relative importance of pressure gradients and bed shear stresses in the sediment transport within the surf zone.