SYNBIOS Project Description
The SYNBIOS project is a basic research project funded by the french National Research Agency (ANR) and devoted to coastal dynamics and coupled bio-dynamical studies. The main goals of this proposal are to better understand the submeso scale processes which affect the dynamics and the primary production of coastal areas. We will focus on the specific role of steep continental slope on the cross-shelf transport of tracers and its impact on the vertical and horizontal distribution of biogeochemical species.
The main goals of the project SYNBIOS are:
1- A thorough understanding of the dynamical processes which control the cross-shelf exchanges and the biological activities above steep continental slopes. Identify the main dynamical regimes and the relevant control parameters of these processes.
2- Estimate the optimal resolution (horizontal and vertical) needed to describe accurately, in regional models, the dynamical and biological coastal processes across the continental slope.
3- Provide a high-resolution dataset of idealized laboratory experiments (on coastal flow interacting with a steep topography) valuable to benchmark numerical models. Several idealized test cases will model the continental slope variations of the south-eastern Mediterranean Sea.
4- Build an idealized biogeochemical model for coastal area taking into account two trophic chains. Study the impact of various coastal dynamics (steep or smooth slopes, geostrophic or frontal currents) on the interaction between nutrient-rich region along the coast and offshore oligotrophic region.
5- Theses processes studies will be compared to recent in-situ measurements and high resolution coastal models (HYCOM and NEMO MED36) in two specific areas: the eastern coast of the Arabian Peninsula and the Libyo-Egyptian coast.
One novelty of this project is to show that laboratory experiment can be a cost-effective way of aiding in the development of numerical models. Benefiting from the LMD-ENSTA rotating platform, an efficient tool to study the impact of non-hydrostatic and ageostrophic submesoscale structures (eddies and filaments) on the coastal circulation, modern data acquisition techniques will be developed in order to provide datasets with high spatio- temporal resolution. According to the recent development of high-resolution camera technology, 16megapixels sensors CCD camera are now available for reasonable prices. Hence, we could expect to provide one of the highest spatial resolution (600x400 velocity vectors) measured in rotating experiment. This laboratory datasets will be available for model testing and validation.
The second novelty is to develop an idealized biogeochemical model for coastal area and to couple this simplified model with a multi-layer shallow-water model. Previous studies investigating the effect of coastal ocean physics on ecosystems have mostly considered regional cases or applications; therefore, they encompassed several processes, for which a clear separation of their influence on biology was not obvious. Here we propose to couple individual physical processes with biogeochemical dynamics. Thus we can precisely assess the impact of each process on the ecosystem evolution. The influence of interacting processes will be achieved only after this first stage.
The methodology which comprises theory, laboratory experiments, in-situ data analysis and numerical modeling, is also a strong point and a novelty of our study, allowed by the experience of the proposing teams. This multiple approach allows both a mutual validation of the techniques and results, and a generalization of conclusions made in a specific case, to more general contexts.
The SYNBIOS project is divided into six main tasks corresponding to different scientific approaches and/or scientific tools. The Task1 deals with the Dynamical Process Studies (DPS) of the interaction of coastal dynamics (current, wave, eddies) with a steep continental slope. Task 2 corresponds to Laboratory Experiments (LE) studies of a coastal current interacting with various bottom slopes. The Task 3 deals with Biological Process Studies (BPS). While the Task 4 corresponds to the coupling of the simplified coastal ecosystem (task 3) with idealized multi-layer model of the coastal dynamics over the continental slope (task 1.1). Hence, the starting of Task 4 depends on the achievement of the Tasks 1 and 3 (red connections in the organization chart). These various process studies will be used to understand the coastal circulation in two specific areas: Task 5 is related to the Arabian Sea Test Case (AS-TC) and Task 6 to the Eastern Mediterranean Sea Test Case (EMS-TC). The five tasks (1, 2, 3, 5 and 6) are independent of each other. However, they will be done in strong interaction in order to provide a mutual validation of the techniques and results. These interactions are represented by blue lines in the organization chart below. These complementary approaches (tasks) will induce a generalization of conclusions made in a specific case, to more general contexts.
