Institut Méditerranéen d’Océanologie

LATEX (English description)

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The LATEX project aims to study the influence of the coupled physics and biochemistry dynamics at (sub) mesoscales on the matter and heat transfers between the coastal zone and the open ocean. This aim corresponds to one of the priority listed by the French national program LEFE - IDAO and CYBER (“Matter and energy transfer (…) at the interface between the continental slope and the coastal margin”, § 2.1 and 2.3). Mesoscale and sub-mesoscales hydrodynamic features, taking place at the interface between the continental slope and the coastal margin, are part of the processes that are important for the understanding of transfers between the coastal zone and the open ocean. Nonetheless, these processes are still not fully known. Indeed, at these scales, the influence of the physical processes on biogeochemistry is clearly shown in numerical studies. But confirmations by experiments are difficult, and hence rare, because experiment strategies generally differ greatly whether they oriented towards a physical study or a biogeochemical one.

For the last 10 years, the LOPB has been PI in a number of national projects which have included cruises in the Gulf of Lion (Moogli, Sarhygol, Golts, Golts/Argol, Ecolophy/Argol). But the strategy of these cruises was oriented either towards physics or biogeochemistry. Now the LOB proposes a new experimental strategy (new for the LOB in the Gulf of Lion) to do a real coupled hydrodynamic and biogeochemical experiment. The LATEX strategy is based on a combined use of satellite data, numerical modelling and Lagrangian in situ measurements (Lagrangian buoys and a tracer experiment). The main objective of LATEX is to study the impact of (sub) mesoscale structures –present in the Gulf of Lion- interacting with the Northern Current on the evolution of conservative or biogeochemical tracers’ distributions. Thanks to this study, questions such as the following ones will hopefully be answered. Do these structures facilitate the horizontal transfer across the continental slope and the slope current ? What are the consequences on biogeochemistry of the interaction of the structure with the NC ?