Section: Application Domains

Ocean dynamics

Participants : Hussein Yahia, Oriol Pont, Annick Lesne, Antonio Turiel, Véronique Garçon, Christine Provost, Joel Sudre.

In Oceanography, the main objective is to bring the MMF as a radically new and powerful tool to study ocean dynamics in satellite acquisition datasets. The use of the Microcanonical Multiscale Formalism in Oceanography and Earth Observation emerges naturally from a first set of results, exposed for instance in  [16] , which schows that the geometric structures derived from singularity exponents are advected by the ocean flow.

• Obtention of the quasi-geostrophic stream function from acquisition data. Validation.

• Study of the relationships between ocean dynamics and the geometric super-structures derived from singularity exponents, particularly w.r.t. the evaluation of intantaneous oceanic currents. More generally, relate the geometric super-structures in the MMF to ocean dynamics.

• Geometric super-structures in ocean colour data (marine biogeochesmistry, patchiness and sub-mesoscale structure of cholorophyl fields, CDOM (colored dissolved organic material), OPC (organic particular carbon), dispersion of tracer fields during in-situ experiments with iron fertilization or chemical pollutants, study of algae blooms with the MMF, dynamics of eastern coastal upwellings.

• MMF and mixing phenomena in ocean colour data. Evaluation of turbulence in the oceans.

• Combination of information given by the MMF from merged SST (Sea Surface Temperature) and altimetry, comparison with geometric super-structures computed at the same temporal frequency on ocean colour data. Interpretation in terms of dynamic biological activity, source and sink determination in the tracer equation conservation.

• Use of operational products derived from GEOSTAT; energy transfer between the ocean and the atmosphere. Ocean/climate interaction: more than 50% of vertical transfers between the ocean and the atmosphere are associated to sub-mesoscale (< 10 km). Presently, this spatial resolution is out of altmetric range. The importance of the MMF lies in the fact that there is no synoptic acquisition of vector fields at sub-mesoscale resolution. The first experimental satellite to acquire the dynamics at these scales will be SWOT, to be launched in 2012 if budget prevision goes as planned. SWOT will only be experimental, in test phase during 3 to 6 months only.

• MMF and climate change, through the study of ocean-atmosphere heat transfers and greenhouse gazes sources and sinks.