Modelling offshore sand waves: effects of suspended sediment transport

seas, such as the North Sea, sand waves can be observed forming regular bed patterns. Present numerical sand wave models only take bed load transport into account, the most important transport mechanism for sand waves. We expect the suspended sediment transport becomes significant for full amplitude sand waves. Within this study, we investigate the influence of suspended sediment on sand wave dynamics. Firstly, we model the suspended sediment transport with a depth-averaged transport formula. Furthermore, we will employ a vertical sediment concentration profile model. The latter approach is able to describe the phase-lag due to the time difference in pick-up and settling. The suspended load formulation enables modelling influences of wind waves on sediment transport.