4DMED-Sea

The 4DMED products tools will be specifically designed to address key multi-disciplinary scientific questions and to reduce the knowledge gaps that concern the relation between the Mediterranean Sea dynamics and the most relevant biogeochemical/biological/ecological processes, targeting also the bio-physical interactions at the mesoscale and sub-mesoscale.

Three main products are foreseen as project outcomes:
- 4DMED-2D PFT/Kd (L3) will provide innovative estimates of the concentration of diatoms, haptophytes, dinoflagellates, green algae and prokaryotes as well as diffuse attenuation coefficients.
- 4DMED-3D physical variables (L4) will provide high resolution data-driven reconstruction of Mediterranean temperature, Salinity and Geostrophic Velocities from the surface down to 150 m
- 4DMED-3D bio-physical variables (L4) will provide high resolution data-driven reconstruction of Mediterranean Chlorophyll-a, temperature, salinity, and geostrophic velocities from the surface down to 150 m

4DMED data products and associated documentation will be provided as open data.

4DMEDSea DataChallenge

The ESA-4DMEDSea Data Challenge is designed to assess experimental sea surface height gridded products produced within the ESA-4DMEDSea project. Through a dedicated website and associated GitHub repository, participants can access essential resources, including input datasets, independent validation data, and comparison tools for evaluating their methodologies.

Currently, the evaluation process involves a comparison among the Copernicus Marine Service operational product, MIOST [Ubelmann et al., 2021], and 4Dvarnet [Fablet et al., 2021] mapping techniques. This evaluation employs a range of metrics (RMSE, effective resolution, …) to gauge the accuracy, reliability, and efficiency of the gridded sea surface height and currents. Leveraging independent datasets such as along-track altimeter and in-situ drifter data, the framework aims to provide insights into the efficacy of different mapping reconstructions. Main mapping scores are consolidated in a readily accessible scoreboard, facilitating informed decision-making for researchers and users concerning the selection and application of diverse mapping approaches.

References:
MIOST: Ubelmann, C. et al. Reconstructing ocean surface current combining altimetry and future spaceborne doppler data. J. Geophys. Res. Ocean. 126, e2020JC016560 (2021).
4dVarNet: Fablet, R., Amar, M. M., Febvre, Q., Beauchamp, M. & Chapron, B. End-to-end physics-informed representation learning for satellite ocean remote sensing data: Applications to satellite altimetry and sea surface currents. ISPRS Annals Photogramm. Remote. Sens. & Spatial Inf. Sci. (2021).