The interactions between ageostrophic processes and large scale dynamics in the western part of the Gulf of Lion (NW Mediterranean) play a fundamental role in regulating water exchanges between the continental shelf and the open sea. The dominant regimes emerging from these interactions were successfully characterized during the Lagrangian Transport Experiment (LATEX, 2008-2010) thanks to a multi-platform approach which included in-situ observations, satellite measurements and numerical model simulations. During the Latex10 campaign (September 1-24, 2010), in-situ Lagrangian Coherent Structures reconstructed from drifter trajectories allowed to identify an alongshore corridor through which coastal waters escaped the Gulf. Satellite imagery indicated that the offshore boundary of the corridor was associated with a strong frontal region. Glider profiles allowed to reconstruct the vertical structure of the front, and ship-based ADCP currents to estimate the associated horizontal fluxes. Realistic numerical simulations showed that this regime alternates with periods during which the circulation is dominated by coastal anticyclones (also observed in previous campaigns). Model results, along with a regional satellite altimetry product, allowed to characterize the influence of the two regimes in regulating cross-shelf exchanges.