Abstract's details

Bathymetry improvement and high-resolution tidal modelling at regional scales

Mathilde Cancet (NOVELTIS, France)


Ergane Fouchet (NOVELTIS, France); Etienne Sahuc (NOVELTIS, France); Florent Lyard (LEGOS/OMP/CNRS, France); Gérald Dibarboure (CNES, France); Nicolas Picot (CNES, France)

Event: 2022 Ocean Surface Topography Science Team Meeting

Session: Tides, internal tides and high-frequency processes

Presentation type: Type Poster

Contribution: PDF file


Coastal processes (tidal currents, storm surges, waves) are highly dependent on bathymetry and directly impact offshore and coastal activities and studies. Many studies and applications lie on a growing modelling effort of the ocean and the limited accuracy of bathymetry, especially on the continental shelves, contributes to degrade the numerical model performance despite significant use of in-situ and satellite measurements assimilation. In particular, the tidal models are very sensitive to the bathymetry accuracy on the shelves, where the ocean tides show the largest amplitudes and are strongly non-linear.
The increase in the grid resolution, combined with local model tuning, is one of the means to improve the tidal model performance in the coastal regions and large improvements have been achieved thanks to this approach. However, increasing the resolution of the model grid implies consistent bathymetry quality and accuracy, which is today the main limiting factor to accurate high-resolution tidal modelling.
In particular, this has a direct impact on the quality of the altimetry sea surface heights as the tide correction is one of the largest corrections on the shelves, ranging from several centimetres to several metres. It is of prime importance for the current and future satellite altimetry missions that already or will enable to retrieve high-resolution coastal observations of the sea surface height, such as Sentinel-3, Sentinel-6/Jason-CS and SWOT.
Various sources of bathymetry data exist but many regions remain poorly known because of too sparse measurements, data access limitation or large temporal variability of the seabed dynamics. In this context, CNES recently funded a project that aimed to improve the bathymetry and the tides in the North-East Atlantic Ocean, the Mediterranean Sea, the Arctic Ocean and around Australia.
The work was divided in several steps: 1) an inventory of the existing bathymetry datasets in the regions of interest; 2) the integration of the collected datasets into a reference global bathymetry dataset; 3) the evaluation of this new bathymetry dataset through the implementation of a regional hydrodynamic tidal model configuration; 4) the assimilation of tidal observations into the hydrodynamic model and the production of high resolution regional tidal atlases.
This paper presents the performance of these four new regional tidal models that pave the way for the implementation of the new global tidal model, FES2022.

Poster show times:

Room Start Date End Date
Mezzanine Tue, Nov 01 2022,17:15 Tue, Nov 01 2022,18:15
Mezzanine Thu, Nov 03 2022,14:00 Thu, Nov 03 2022,15:45
Mathilde Cancet