Validation of a 3d modelling system with sediment transport capabilities in the nw iberia coastal upwelling region

Abstract

The impacts of global warming and anthropogenic activities on our ecosystems have become the utmost urgent question. Numerical modelling is a powerful tool to better understand the response of marine environments to these changes. A state-of-the-art 3-dimensional modelling system has been implemented and evaluated to study sediment transport processes in the NW Iberian coastal upwelling region. The modelling system included the free-surface, split-explicit, terrain-following model CROCO (Coastal and Regional Ocean COmmunity model, v1.0) (https://www.croco-ocean.org) and a sediment transport module. A third-generation spectral wave model SWAN (Simulating Waves Nearshore) was running in parallel to include a realistic wave field. Results obtained from the model were validated with observations of hydrodynamic, wave and backscatter data and with the estimates of bottom shear stress by Villacieros-Robineau et al. (2019). The model output depicts well the evolution of hydrodynamics and waves when compared to the measurements. The combined wave-current shear stress at the bottom correlated well with the backscatter signal close to the surface sediments and showed a high concordance with previously published results (Villacieros-Robineau et al., 2019). The overall good agreement between observations and model results gives a high degree of confidence that the model reproduces the dynamics of the shelf system reliably in 3D. In this way, the implemented model will get decisive insights into the driving forces on the Iberian continental shelf