Longshore current dislocation on barred beaches
نویسنده
چکیده
[1] We present a numerical investigation of longshore currents driven by breaking waves on barred beaches. Alongshore inhomogeneity in the wave envelope or bathymetry leads to the generation of strong dipolar structures when the waves are breaking. The dynamics of these structures transfer momentum from the bar of the beach into the trough. This study is pursued using a new model that allows long simulation times and realistic wave amplitudes. We study two idealized settings that are expected to produce current dislocation, as observed in field experiments. In one setting the current maximum is dislocated; in the other the current is diffused, but the maximum is not shifted.
منابع مشابه
Wave Group Forcing of Low Frequency Surf Zone Motion
The nearshore potential vorticity balance of Bowen and Holman (1989) is expanded to include the forcing from wave group-induced radiation stresses. Model results suggest that the forcing from these radiation stresses can drive oscillations in the longshore current that have a spatial structure similar to linear shear instabilities of the longshore current. In addition, the forced response is ne...
متن کاملShort - term morphodynamic changes in a fetch limited beach at the Ebro delta ( Spain ) , under low wave - energy conditions
Mosso, C., Sierra, J. P., Gracia, V., Mestres, M., and Rodriguez, A. 2011. Short-term morphodynamic changes in a fetch limited beach at the Ebro delta (Spain), under low wave-energy conditions. Journal of Coastal Research, SI 64 (Proceedings of the 11th International Coastal Symposium), – . Szczecin, Poland, ISSN 0749-0208 Sandy beaches in fetch-limited environments are protected from large oce...
متن کاملA Unique Finite Element Modeling of the Periodic Wave Transformation over Sloping and Barred Beaches by Beji and Nadaoka's Extended Boussinesq Equations
This paper presents a numerical model based on one-dimensional Beji and Nadaoka's Extended Boussinesq equations for simulation of periodic wave shoaling and its decomposition over morphological beaches. A unique Galerkin finite element and Adams-Bashforth-Moulton predictor-corrector methods are employed for spatial and temporal discretization, respectively. For direct application of linear fini...
متن کاملImpacts of wave and tidal forcing on 3D nearshore processes on natural beaches. Part II: Sediment transport
This is the second of two papers on the 3D numerical modeling of nearshore hydroand morphodynamics. In Part I, the focus was on surf and swash zone hydrodynamics in the cross-shore and longshore directions. Here, we consider nearshore processes with an emphasis on the effects of oceanic forcing and beach characteristics on sediment transport in the crossand longshore directions, as well as on f...
متن کاملImpacts of wave and tidal forcing on 3D nearshore processes on natural beaches. Part I: Flow and turbulence fields
The major objective of this study was to develop further understanding of 3D nearshore hydrodynamics under a variety of wave and tidal forcing conditions. The main tool used was a comprehensive 3D numerical model – combining the flow module of Delft3D with the WAVE solver of XBeach – of nearshore hydroand morphodynamics that can simulate flow, sediment transport, and morphological evolution. Su...
متن کامل