Production of an ocean color archive focused on the coastal waters of Metropolitan France on behalf of the ODATIS data hub to support scientific research and marine studies

Coastal areas are hotspots of human activity and are among the most productive ecosystems, providing essential resources and services. However, these zones are increasingly under pressure from human activities and climate change, which threaten their ecological balance and long-term sustainability. Remote sensing provides a crucial tool for monitoring coastal areas, allowing for timely detection of environmental changes and human impacts. More specifically, ocean color on coastal waters is a key parameter where significant progress can be made, especially in developing new algorithms and making relevant data products more accessible. The "Ocean Color" Scientific Expertise Consortium under the ODATIS data hub, part of the Data Terra Research Institute (CNES), has identified a series of innovative products and algorithms that address the scientific community's needs at a national scale in France. To this end, ACRI-ST has been tasked by CNES to process a medium-resolution archive of ocean color data (300m) specifically for the French metropolitan coastlines. This project focuses on applying coastal-specific atmospheric corrections and biogeochemical algorithms that meet thematic scientific needs, based on input data from MERIS, MODIS, and OLCI sensors. The resulting coastal products are then made publicly and freely available through a user-friendly web interface. This presentation will cover the data production, validation processes, and public dissemination efforts undertaken within this project. The initiative will, among other things, enable a comparison of a wide range of products and provide access to a long-term archive of qualified ocean color data. This work could potentially be extended to other regions of the world in the future.