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EOC FWS - A satellite and in-situ field experiment in a turbulent ocean: Diagnosis of vertical exchanges associated with submesoscales. Impacts on air-sea exchanges and ecosystems

Workshop (Foresight)
EUR-OCEANS organisation / funding

This FWS description is adapted from the proposal.


This workshop is embedded within Axis 1 “The ocean engine at very high resolution” of the recently labelled Centre of Excellence named “LABEX MER” and located within the marine sciences campus in Brest (France). The ambition of this axis is to make major advances, over the next 10 years, in our understanding of the contribution of small scales to the dynamics of the ocean as well as the interactions of these small scales with larger scales. Designing and implementing an innovative field experiment to monitor small scales processes and their dynamics if one of the scientific targets of the axis.

[Note: a conference and a flagship on meso/submesoscale features and their effects on biogeochemical cycles and ecosystems have previously been funded by EOC.]


Motivation to study the vertical exchanges of tracers associated with mesoscale eddies (with a diameter of 50-200km and depth extension of 500-1000m) is that the mean concentration of most oceanic tracers changes rapidly with depth. Because mesoscale processes may transport these tracers vertically, it has been hypothesized that these vertical exchanges may strongly affect not only the meridional heat fluxes (that impact the large-scale oceanic circulation, Ferrari and Wunsch, ARFM, 2009) but also the entire biogeochemical system and therefore the global tracer budgets (McGillicuddy, GBC, 2003) .

[...] We propose to setup an extensive and innovative field (both satellite and in-situ) experiment specifically devoted to the monitoring of submesoscale structures resulting from the interactions between mesoscale eddies and on the quantification of their impact on the spatial organisation of the biomass density (in terms of the dominance of specific species) and also on the air-sea fluxes. This is the topic of our project.

Design and implementation overview

Although mesoscale eddies evolve on a time scale of the order of 10 days (often less), submesoscales evolve more quickly (on a time scale of one or two days). Because of these short time scales, conventional observational strategies are insufficient to provide synoptic and 3-D views of meso/submesoscale dynamics and of their biological consequences. This means that the design of an appropriate experiment requires a strategy that well departs from the classical in-situ experiments. To meet these constraints, the strategy of the field experiment should be based on real-time satellite monitoring of a square domain with a size of no more than 500km (including two or three eddies) as was done in Legal et al. (JPO, 2007). New products developed by CLS based on altimeter data and ocean colour image, associated with SST field from AMSR-2 (new AMSR from JAXA) and new dynamical methods, should allow to diagnose precisely the characteristics of the square domain considered, in terms of mesoscale and submesoscale dynamics, in order to assess the vertical exchanges (Klein et al., 2009; d'Ovidio et al., 2010; Kudryavtsev et al., 2012). [...]

Objective and programme outline

This workshop will be aimed to call for interest and aggregate the national and international community around the project and to assess the observing systems and strategies that are needed to achieve the project objectives. A first part will be devoted to scientific talks on processes (either physical, biogeochemical, biological) at fine scales in the ocean. A second part will be devoted to observing instrument or platforms dedicated to such oceanic scales. Lastly, the key scientific questions that need to be addressed by the new project and the final strategy of the field experiment will be discussed [including an implementation plan and a research proposal to be submitted to the national and international research funding agencies].

Contact and links

Patrice.Klein [at]
Sabrina.Speich [at]


Activity leader(s): 
Patrice Klein (Ifremer), Sabrina Speich (UBO)
Brest, France
Financial support: 
15 k€ from EOC to organizers
Start date: 
End date: 

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