The observation and modelling, either hydrodynamical or by data assimilation approach, is a key activity in the ECOLA group. The study of the ocean tides cover a large variety of scales and processes:
Tides are one of the most energetic hydrodynamic processes found in shelf and coastal seas. They interact strongly with the local circulation, and their precise determination is needed in realistic ocean modelling. In parallel, tides need to be precisely corrected in satellite altimetry observations. Global and regional oceans tidal atlases are routinely produced to provide altimetry sub-centimetric corrections (FES2012/2014, COMAPI atlases, etc). The tidal atlases are produced from the T-UGOm model and the SpEnOI data assimilation code, on unstructured grids aimed to comply with the variable scales of tides with depth. The global tidal atlas FES have been elected to be official corrections for several altimetry and gravimetry space missions, especially TP/Jason1-2. Coastal harmonic constants dataset derived from altimetry observations have also been made available in collaboration of the CTOH service.
- 2-dimensional, shallow-water tides (barotropic):
- 3-dimensional tides
The 3-dimensional dynamics of tides are much less well known as the 2-dimensional ones, and their precise modelling remains a challenge. Even in well-mixed waters, the vertical structures of the tides is quite complex, because of their dependency upon bottom friction and turbulence, which is affected by many other processes. In stratified waters, the generation, propagation and dissipation of internal tides is still today a fully open field of research. ECOLA is strongly committed in this field of activity, either through national projects (ANR COMODO) and international ones (OSTST, SWOT SDT).
Beside its research activities, ECOLA, in the frame of the SIROCCO service and the COMODO project, is strongly involved in developping and sharing numerical applications for the processing and modelling of tides for the benefit of the ocean reasearch community. The software package Tidal ToolBox (TTB), covering inline and off-line needs in data processing and tidal modelling, is now available and is deployed at IFREMER, LNH and SHOM.