Sensitivity study on the main tidal constituents of the Gulf of Tonkin by using the frequency-domain tidal solver in T-UGOm.

Tidal dynamics consequences on hydro-sedimentary processes are a recurrent issue in estuarine and coastal processes studies and accurate tidal solutions are a prerequisite for modelling sediment transport, especially in macro-tidal regions. The motivation for the study presented in this publication is to implement and optimize the model configuration that will satisfy this prerequisite in the frame of a larger objective to study the sediment dynamics and fate in the Red River delta to the Gulf of Tonkin from a numerical hydrodynamical-sediment coupled model. Therefore we focus on the main tidal constituents to conduct sensitivity experiments on the bathymetry and bottom friction parameterization. The frequency-domain solver available in the hydrodynamic unstructured grid model T-UGOm has been used to reduce the computational cost and allow for wider parameter explorations. Tidal solutions obtained from the optimal configuration were evaluated from tide measurements derived from satellite altimetry and show a strong improvement (compared to pre-existing tidal atlases) due to an improved bathymetry dataset and fine friction parameters adjustment. However, our experiments seem to indicate that the solution error budget is still dominated by bathymetry errors, which is the most common limitation for accurate tidal modelling. [ABSTRACT FROM AUTHOR]