Sensitivity of modeled nearshore oblique bars to wave and sediment transport formulations

Two models are discussed that describe the initial formation of nearshore large-scale rhythmic morphology due to feedbacks between the wave-driven large-scale flow and the erodible bottom. The aim is to gain fundamental knowledge about the sensitivity of modeled bar characteristics to the description of waves and sediment transport, in case of obliquely incident waves and planar reference beach profiles. The two models differ mostly in the wave description (with different degrees of complexity) and both of them are supplied with two different sediment transport formulations. Systems of sand bars with longshore rhythmicity emerge as free instabilities of the system. Including randomness in wave heights largely affects the modeled bar growth and dynamics. Results are also different for the two sediment transport formulations. In particular, the differences in the cross-shore distribution of the wave stirring function lead to different characteristics of the fastest growing modes.