Operational detection of sargassum from sun-synchonous and geostionnary satellites

Since 2011, unprecedent massive landings of sargassum seaweed (Sargassum fluitans and Sargassum natans) have been observed along the shorelines of a huge area encompassing the Gulf of Mexico, the Caribbean Sea and West Africa,  having tremendous negative impacts over local communities.

Seen as a natural resource in the development of blue economy downstream applications or as an environmental threat for risk assessment and coastal management, sargassum data requires to be monitored at large geographical and temporal scales but also at local and real time scales.

With the development of floating algae indexes, the use of satellite observations is a key to answer these needs, as it allows to depict the abundance of sargassum and monitor their movements and trends at basin scale with wide swath sensors (MODIS-Aqua, OLCI Sentinel-3), and at local scale with high spatial resolution sensors (Sentinel-2, Landsat-8) and high temporal resolution (geostationary satellites GOES-16).

Since 2018, with the initial support of ESA, CLS has been developing and operating an operational system to provide sargassum detection products from a range of 6 sun-synchronous satellites in real time, using wide swath (MODIS, OLCI at 300m resolution) and high resolution optical sensors (MSI, OLI at 20m resolution).

Since 2020, with the initial support of CNES, HYGEOS has been developing a novel processing of geostationary satellite data on ABI sensor on board GOES-16 that allows to extend the satellite coverage over one day thanks to its 10-minute temporal resolution.

In the frame of the SODA project of the Copernicus Marine Service Evolution Program https://marine.copernicus.eu/about/research-development-projects/2022-2024/soda , the sargassum operational detections algorithms are being reviewed in the aim of providing the scientific research community and private downstream sectors with the best products adapted to each user needs.

The presentation will highlight the first results of the SODA project, focusing on the improvement of the level 1 to level 2 sargassum processing on OLCI and MODIS and on the work done on the ABI sensor.