Dynamics and transport from the boundary Northern Current toward the Toulon Bay: multi-platform observations and downscaling modelling approaches

Coastal regions are vulnerable areas with often high population density, as well as tourism and maritime activities that may have negative impact on the environment. From a physical point of view, coastal areas may be characterized by high gradient topography and irregular coastline shapes resulting in complex dynamic systems. The monitoring of coastal circulation becomes necessary to support coastal management and to understand the high variability of the dynamics. The simultaneous use of comprehensive observational systems and numerical models may compensate the drawback of each method used separately. The Toulon coastal area is under investigation in this paper by means of HF RADAR and ADCP observations coupled with nested models. The integration of the different data sets allows the monitoring of the coastal ocean continuum from regional oceans and shelf areas. Summer and winter 2018 data are analyzed to depict the seasonal variability of the regional circulation mainly characterized by the geostrophic Northern boundary Current, the wind-driven bay circulation and the connectivity between the bay, the surrounding Marine Protected Area and the open sea.