A New Morphodynamic Instability Associated With Cross‐Shore Transport in the Nearshore

The existing theory for shore-transverse rhythmic sand bars relies on morphodynamic instabilities involving the wave-driven longshore current and rip currents. Intriguingly, transverse finger are common coasts with sediment excess, something not related to those Here we show that, if actual beach profile is above equilibrium profile, cross-shore transport can induce an instability triggered by onshore together wave refraction emerging bars. We use a numerical model that filters out dynamics associated currents but includes simplified version of able reproduce formation alongshore spacing scales wavelength incident waves extent approximately equal distance from shore depth closure. modeled compare qualitatively well observations at El Trabucador back-barrier (Ebro delta, Western Mediterranean Sea).