Model studies of transport of sedimentary material in the western Baltic

The theoretical description of sedimentation, resuspension and transport of sedimentary material is an important prerequisite for the modeling of the benthic–pelagic interaction, the impact of dumping on the coastal environment and the fluxes of material from coastal areas into the deep basins. The present study aims at model studies of the transport of sedimentary material in parts of the Baltic Sea and is based on a model system which links a general ocean circulation model (Modular Ocean Model, MOM 3) adapted to the Baltic, a wave model, a bottom boundary and a sediment transport model. Several model simulations are carried out in order to analyze the spatial distribution of the bottom shear stress in response to varying forcing conditions. Regions of high and low bottom shear stresses as well as potential areas for erosion are identified. Further transport and deposition patterns of different materials under varying forcing conditions are studied. We find significant seasonal variations of the calculated transport rates. Potential accumulation areas of fine material, which corresponds to fluffy layers or dormant stages (cysts), are investigated. The simulation shows that the material accumulates at the slopes of the basins within a few weeks under winter conditions.