Rafael Almar, Rodrigo Cienfuegos, Eduardo Gonzalez, Patricio Catalán, Hervé Michallet, Philippe Bonneton, Bruno Castelle, Leandro Suarez


A conceptual analysis of the coupling between bars and infragravity waves is performed combining laboratory experiments and numerical modeling. Experiments are carried out in a wave flume with a barred profile. The Boussinesq fully-nonlinear model SERR1D is validated with the laboratory data and a sensitivity analysis is performed next to study the influence on the infragravity wave dynamics of bar amplitude and location, and swash zone slope. A novel technique of incident and reflected motions separation that conserves temporal characteristics is applied. We observe that changing bar characteristics induces substantial variations in trapped energy. Interestingly, a modification of swash zone slope has a large influence on the reflected component, controlling amplitude and phase time-lag, and consequently on the resonant pattern. Variations of trapped infragravity energy induced by changes of swash zone slope reach 25 %. These changes in infragravity pattern consequently affect short-wave dynamics by modifying the breakpoint location and the breaking intensity. Our conceptual investigation suggests the existence of a morphological feedback through the action of evolving morphology on infragravity structures which modulates the action of short-waves on the morphology itself.


Longwave dynamics; Sandbar; Swash; Nearshore; Laboratory experiment; Non-linear Boussinesq wave modeling; Radon transform; Incoming/Outgoing wave separation; Infragravity resonance

Full Text:



Aagaard, T., Bryan, K., 2003, Observations of infragravity wave frequency selection. Continental Shelf Research, 23, 10, 1019-1034.

Baldock, T.E., Holmes, P., 1999. Simulation and prediction of swash oscillations on a steep beach. Coast. Eng. 36, 219-242.

Baldock, T. E., O'Hare, T. J. and Huntley, D. A. 2004. Long wave forcing on a barred beach. J. Fluid Mech. 503, 321-343.

Cienfuegos, R., Barthelemy, E., Bonneton, P., 2010a. A wave-breaking model 34 for Boussinesq-type equations including roller effects in the mass conservation equation. J. Waterw. Port Coastal Oc. Eng. 136, 10-26.

Cienfuegos, R., Duarte, L., Suárez, L. and Catalán. P. 2010b. Numerical Computation of Infragravity Waves and Velocity Profiles using a Fully Nonlinear Boussinesq Model, 32nd International Conference on Coastal Engineering, Shanghai, China, 2010.

Deans, S., 1983. The Radon transform and some of its applications, 1st Edition. Wiley, New York.


Guza, R.T., Thorton, E.B., Holman, R.A. 1984. Swash on steep and shallow beaches. Proceedings of the 19th International Conference on Coastal Engineering, ASCE, 708-723.

Michallet, H., Grasso, F. and Barthélemy, E. 2007. Long waves and beach profiles evolutions. Journal of Coastal Research, SI50, 221-225.

O'Hare, T.J., and Huntley, D.A. 1994. Bar formation due to wave groups and associated long waves, Marine Geology, 116, 313-325.

Ruessink, B.G., 1998. The temporal and spatial variability of infragravity waves in a barred nearshore zone. Continental Shelf Research, 18, 585-605.

Sénéchal, N., Bonneton, P., Dupuis, H. 2002. Field experiment on secondary wave generation on a barred beach and the consequent evolution of energy dissipation on the beach face. Coastal Eng 46, 233-247.

Senechal, N., Abadie, S., Gallagher, E., MacMahan, J.H.M., Masselink, G., Michallet, H., Reniers, Ad J.H.M., Ruessink, B.G., Russell, P.E., Sous, D., Turner, I.L., Ardhuin, F., Bonneton, P., Bujan, S., Capo, S., Certain, R., Pedreros, R., Garlan, T. 2011. The ECORS-Truc Vert'08 nearshore field experiment: presentation of a three-dimensional morphologic system in a macro-tidal environment during consecutive extreme storm conditions, Ocean Dynamics, DOI: 10.1007/s10236-011-0472-x.

Symonds, G., Huntley, A., Bowen, A., 1982. Two-dimensional surf-beat: long-wave generation by a time-varying breakpoint. J. Geophys. Res. 87, 492-498.

Van Dongeren, A.R., Battjes, J.A., Janssen, T.T., van Noorloos, J., Steenbergen, K., Reniers, A. 2007. Shoaling and shoreline dissipation of low-frequency waves, Journal of Geophysical Research, 112 (C02011).

Wijnberg, K.M., and Kroon., A., 2002. Barred beaches, Geomorphology 48, 103-120.