Coastal zones are essential for social and economical developments. Located at the interface between ocean and continent, the coasts are vulnerable to environmental hazard and are currently facing an intensification of risk associated with increasing human pressure and the context of global climate change. This project focuses on two regions of the world particularly exposed to coastal vulnerability: West Africa and Vietnam. The environmental conditions governing hydro-sedimentary functioning differ drastically between the two regions. Erosion in West Africa is induced all year long by high-energy long swells; in contrast, Vietnam shows paroxystic events induced by typhoons. Even though the societal issues are manifest in these areas, their hydro-sedimentary functioning remains poorly known and limits social and economical development. The objective of the COASTVAR project is to advance our understanding by characterizing the morphological evolution (aerial and submerged), the driving forces and hydro-morphodynamic processes, from event to seasonal and interannual scales. Emphasis will be given to extreme events and their long-term effect, and to surf-shelf exchanges associated with the wave-induced circulation. In the first project task, innovative observational tools (video imagery and drone) will be used in addition to conventional instruments. In a second task, deep-water wave conditions will be downscaled to the beach, then nearshore configurations of a 3D coupled wave-current model will be set up. In a third task, the ECORS beach evolution predictor (PEA SHOM-DGA), which was yet only tested in mid-latitude environments, will be applied for the first time to tropical coastal systems. Our objective here is to obtain a generic operational tool that can be applied to any coast in the world. The research developed in the COASTVAR project has a strong dual aspect. First, it will provide the first high quality survey and forecasting system for the selected regions (waves, currents and bathymetry), which will be highly relevant to military action. Then, it will propose tools to anticipate coastal risks (erosion and submersion), quantify vulnerability and exposure of people to hazard, and lay solid grounds to improve coastal management.

The EPIGRAM project concerns the dynamics of the French Atlantic marginal and coastal areas (Bay of Biscay and Channel). It is indeed noticeable that most of the researches on the dynamics of the ocean have concentrated on the deep ocean, and its low frequency (climate) variability. The coastal area has only driven back our attention in this field recently, thanks to the development of coastal operational oceanography, and the need for a better monitoring of this area for economical, health or military purposes. One of the main scientific lag is associated with observations at sea: there do not exist 'heavy' campaigns at sea covering this area, and most of the scientific data were collected 15 years ago or more. The project is therefore based on: The definition, realisation and exploitation of campaigns at sea, performed by IFREMER, CNRS/INSU and SHOM. The construction of realistic numerical models of the area, and their comparison with observations at sea, on the basis of process studies. The processes selected for this project are high frequency to seasonal variability at the most. We will concentrate on hydrodynamical studies and the main scientific goal is to improve our comprehension of the main dynamical processes of the continental shelf and margins in the 'Manche' (Channel) and 'Golfe de Gascogne' (Bay of Biscay) and the ability of the numerical models to represent them. The project gathers 14 oceanographic public laboratories with about 50 people. The expected outcomes of the project are: The realisation of four important campaigns at sea and the collection of data for all selected processes. The scientific analysis of the collected data (furniture of diagnostics for all selected processes). Validated realistic numerical models of the area (whose results will be compared to -and limits will be assessed from comparison with- observations at sea). An improved understanding of the major physical processes of the area. In summary, the present project is proposed for a four years period. It concentrates on the physics of the Bay of Biscay and the Channel, in particular on the continental shelf and margin dynamics. It is based on the definition and exploitation of campaigns at sea and numerical modelling studies. The general goal being to improve our understanding and modelling capacity of selected physical processes. These results will be of primary importance for the oceanographic scientific community in general and for nowcast/forecast operational systems. Finally the chosen approach (built on the analysis of oceanic processes) will also facilitate the extension of the results gathered on the present project to other regions.

The quantification of suspended matter concentrations and fluxes is a major challenge in order to better understand the role of coastal areas in the storage and transfer of matter to the deep ocean. These materials concern the elements of biogeochemical cycles (C, N, P, P, Si,...) but also the organic materials, nutrients and contaminants that control and influence the functioning of coastal ecosystems. These material fluxes occur mainly during intense meteorological events (floods and storms) from the catchment areas to the coastal zone where they are temporarily stored and then exported by currents and tides. However, there are very few measurements of these fluxes during intense events and are mainly derived from measurements from satellite images, buoys and other fixed anchorages. The ASTRID-MATURATION "MELANGE" project (real-time Measurement of sEdiment fLuxes in coAstal zoNe using GlidErs) is a follow-up to the ASTRID "MATUGLI" project (autonomous Measurements of coAstal TUrbidity using GLIders) during which was developed a prototype glider for autonomous turbidity measurements. Within the framework of the MELANGE project, it is planned to make this prototype more reliable with the help of an industrialist (ALSEAMAR) and an PME (CENTRALWEB) in order to produce a tool capable of measuring and transmitting measurements of current, turbidity and in fine material fluxes at various spatial (from metre to hundred kilometres) and temporal (from second to several months) scales of the coastal zone. This tool could eventually be used to monitor coastal water quality under the Water Framework Directive and the Marine Environment Strategy Framework Directive for marine parks, for example, and to monitor underwater current and visibility for military applications, but these data will also be used to feed hydrodynamic models for coastal forecasting.

This proposal focuses on the first thematic axis: complex systems modeling, and closely respond to the modeling of environmental sciences thematic of the call for proposal, specifically oceanography. The ocean, coupled with other components (atmosphere, continent, and ice) is a building block of the earth system. Recent events have raised questions on social and economic implications of anthropic alterations of the earth system, i.e. both its long-term evolution and extreme events. A better understanding of the ocean system is a key ingredient for improving our prediction of such implications. Ocean models are essential tools to understand key processes, simulate and forecast events of various space and time scales. The whole French ocean modeling community has been recently assembled under the group name COMODO (COmmunauté de Modélisation Océanique). This community is diverse and offers a variety of applications and numerical approaches for ocean modeling; it also relies at various degrees on the international community. For the first time, this proposal reflects a global effort of the French community to strengthen interactions between its members. This common effort will be directed towars two main objectives: improvement of existing models and numerical methods, guidelines for the development of future generation ocean models. Existing ocean models suffers from a number of well-identified issues that will be addressed during this project. To improve on those issues, the present proposal suggests an innovative evaluation of dissipation mechanisms especially in the context of submesoscale modelling and an improvement of advection-diffusion schemes for the reduction of spurious diapycnal mixing for the accurate representation of active and passive tracers. The second part of the proposal is based on recent advances of our community on vertical coordinate systems, unstructured meshes and non-hydrostatic modelling. The objective is here both to continue fundamental research in these topics and to contribute to the design of future generation models involving their system of equations and numerical methods. The proposed developments will be evaluated thanks to a benchmark suite that covers both idealized test cases design to assess basic important properties of numerical schemes and more complex test cases that will be set-up for a thorough evaluation of progresses made during this project. This benchmark suite, accompanied with the results of the different models, will be made publicly available so as to provide elements for future model developments as well as an opportunity for more theoretical work on numerical schemes to be evaluated in the context of ocean modeling.