A Suspended Particulate Matter Transport Model with Satellite Data Assimilation

In preparation for the numerical model chain of the presently build coastal observation system for the German Bight, the GKSS three-dimensional Suspended Particulate Matter (SPM) transport module was combined with the hydrodynamic circulation model HAMSOM to simulate 2 years of SPM distributions in the North Sea with fine spatial resolution (about 3 km horizontally and 21 vertical layers). In addition, the model was forced by wave fields computed with a WAM model set-up on the same grid. The SPM model calculates distributions of three SPM fractions with different settling velocities in the water column and of the corresponding fine sediment fractions in the upper 20 cm of the bottom. The local shear stress velocities, derived from currents and waves control the processes of sedimentation, re-suspension and erosion. Waves, currents and the different sinking velocities of the three sediment fractions govern the vertical exchange. In the first step, the results were compared to ENVISAT MERIS satellite data and to in-situ measurements, and a quality control system for the satellite data was developed. In the second step, the satellite data were assimilated into the model using a sequential optimal interpolation scheme. Our focus is to develop a tool for SPM calculations based on modeling and data assimilation, which can be used for operational purposes. Results of the SPM simulations with and without assimilation will be presented and compared with independent observations.