Bathymetry improvement and tidal modeling in the North East Atlantic Ocean and in the Mediterranean Sea

Mathilde Cancet (NOVELTIS, France)

CoAuthors

Florence Toublanc (NOVELTIS, France); Florent Lyard (LEGOS/OMP/CNRS, France); Gérald Dibarboure (CNES, France); Nicolas Picot (CNES, France); Thierry Guinle (CNES, France)

Event: 2019 Ocean Surface Topography Science Team Meeting

Session: Tides, internal tides and high-frequency processes

Presentation type: Type Poster

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 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, SWOT and Sentinel-6/Jason-CS.
Various sources of bathymetry data exist but many regions remain not well known because of too sparse measurements, data access limitation or large temporal variability of the seabed dynamics. In this context, CNES funds a project that aims to improve the bathymetry and the tides in the North-East Atlantic Ocean and in the Mediterranean Sea.
The work is 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 hydrodynamic modelling; 4) the assimilation of tidal observations into the model and the production of high resolution regional tidal atlases.
This paper presents the most recent results obtained within this project.
 

Poster show times:

Room Start Date End Date
The Gallery Tue, Oct 22 2019,16:15 Tue, Oct 22 2019,18:00
The Gallery Thu, Oct 24 2019,14:00 Thu, Oct 24 2019,15:45
Mathilde Cancet
NOVELTIS
France
mathilde.cancet@noveltis.fr