Synergy of remote sensing and numerical modelling for suspended matter transport monitoring

Monitoring and modelling of suspended particulate matter (SPM) is an important task especially in coastal environments. SPM concentration is one of the major parameters that regulates the penetration of light into the ocean and hence the primary production. In the past several SPM models have been developed for the North Sea. However, due to waves in shallow water and strong tidal currents in the southern part of the North Sea, this is a challenging task. In general there is a lack of measurements to determine appropriate exchange coefficients. In many satellite borne ocean colour images of the North Sea a plume is visible, which is caused by the scattering at SPM in the upper ocean layer. The intensity and length of the plume depends on the wave and current climate. It is well known that the SPM plume is especially obvious shortly after strong storm events. In this paper a SPM transport model is presented using the synergy of satellite borne ocean colour data and numerical modeling to derive the vertical exchange coefficients due to currents and waves. This results in a model that for the first time is able to reproduce the temporal and spatial evolution of the plume intensity. The SPM model is a quasi-3D model which consists of 3 components: ocean dynamics, SPM vertical exchange and SPM exchange processes with the sea bed. The component for vertical exchange of SPM considers sedimentation and resuspension. The SPM exchange processes with the sea bed take into account erosion, bioturbation by benthos as well as diffusion in the bottom layers.