Ocean Physics Coupling and Biology

The ocean dynamics is structured on scales ranging from a thousand kilometers (basin), a few meters, through the tens / hundreds of kilometers (eddies, fronts). This last scale (meso and sub mesoscale) concentrates 90% of the energy of water bodies. These intermediate and small scales are associated with ancestrophic vertical movements that play a major role in the transport of tracers (nutrient substrates), the distribution of areas of divergence / convergence of ocean currents and the heterogeneity of marine habitats (eddies, filaments). Satellite and acoustic data highlight the important impact of these scales on marine biological activity and the spatial variability of ecosystems, an impact that can be analyzed and understood through numerical modeling. Advances in computational power and observation methods make it possible to address these processes at medium and small scale, which are essential for quantifying the flow of matter and the structuring of marine food webs. The LEMAR expertise in modeling and observation (in particular active acoustics) enables the unit’s researchers to make significant progress in this cutting-edge field, in close relationship with the LabexMer (Axis 1: The ocean machine at very high resolution; Axis 2: The complexity and effectiveness of the biological carbon pump; Axis 6: Evolution of marine habitats and adaptation of populations). The three main areas of research concern:

● Plankton biodiversity at mesoscale

● Carbon export to the deep ocean

● The distribution and behavior of intermediate (zooplankton, myctophid) and higher (elephant seals) levels.