Sargassum Floating Algae Index Detection - Sentinel-2A&B, Landsat-8&9

Composite daily maps of sargassum detection index NFAI (Normalized Floating Algae Index) with multimission dataset using MSI instruments onboard Sentinel-2A&B satellites and OLI instruments onboard Landsat-8&9.

The sargassum detection index (NFAI) maps are computed at 20m on specific HR geographical areas from images of MSI Sentinel-2A & 2B and OLI Landsat-8 & 9, and merged in 300m resolution maps. Note that these daily NFAI data are only partially available each day for satellites acquisitions cover a different part of the area of interest each day : for each pixel, NFAI is provided from MSI Sentinel-2A & 2B images every 2-3 days and from OLI Landsat-8 & 9 images every 8 days at most. By combining MSI Sentinel-2A & 2B and OLI Landsat-8 & 9 images, NFAI data are available for each pixel every 1 to 3 days.

The daily composite maps are provided in delayed-time since December 7th, 2020, to a month before current date. This product is made available as part of SeSaM Space Climate Oobservatory project "Seasonal Sargassum Monitoring" (https://www.spaceclimateobservatory.org/sesam).

The variables available in the product are: nfai_mean = mean value of normalized floating algae index in bin_size degree cell nfai_max = maximum value of normalized floating algae index in bin_size degree cell nfai_min = minimum value of normalized floating algae index in bin_size degree cell nfai_nbpts = number of pixel values of normalized floating algae index in bin_size degree cell