@article{PAR00023839,
  title = {{R}evisited estimation of moderate resolution {S}argassum fractional coverage using decametric satellite data ({S}2-{MSI})},
  author = {{D}escloitres, {J}. and {M}inghelli, {A}. and {S}teinmetz, {F}. and {C}hevalier, {C}rist{\`e}le and {C}hami, {M}. and {B}erline, {L}.},
  editor = {},
  language = {{ENG}},
  abstract = {{S}ince 2011, massive stranding of the brown algae {S}argassum has regularly affected the coastal waters of the {W}est {C}aribbean, {B}razil and {W}est {A}frica, leading to significant environmental and socio-economic impacts. {T}he {AFAI} algal index ({A}lternative {F}loating {A}lgae {I}ndex) is often used with remote sensing data in order to estimate the {S}argassum coverage, and more precisely the {AFAI} deviation, which consists of the difference between {AFAI} and {AFAI} of the {S}argassum-free background. {I}n this study, the {AFAI} deviation is computed using {NASA}'s 1 km {T}erra/{MODIS} ({M}oderate-{R}esolution {I}maging {S}pectroradiometer) and {ESA}/{C}opernicus's 20 m {S}entinel-2/{MSI} ({M}ulti {S}pectral {I}nstrument) for the same sites and at the same time. {B}oth {MODIS} and {MSI} {AFAI} deviations are compared to confirm the relevance of {AFAI} deviation technique for two very different spatial resolutions. {A} high coefficient of determination was found, thus confirming a satisfactory downsampling from 20 m ({MSI}) to 1 km ({MODIS}). {T}hen, {AFAI} deviations are used to estimate the fractional coverage of {S}argassum (noted {FC}). {A} new linear relationship between the {MODIS} {AFAI} deviation and {FC} is established using the dense {S}argassum aggregations observed by {MSI} data. {T}he {AFAI} deviation is proportional to {FC} with a factor of proportionality close to 0.08. {F}inally, it is shown that the factor is dependent on the {S}argassum spectral reflectance, submersion or physiological state.},
  keywords = {ocean color ; {S}argassum ; {AFAI} ; fractional coverage ; {MODIS} ; {S}entinel-2 ; {ATLANTIQUE} ; {CARAIBES} ; {GUADELOUPE} ; {GRENADINES} ; {GOLFE} {DE} {GUINEE}},
  booktitle = {},
  journal = {{R}emote {S}ensing},
  volume = {13},
  numero = {24},
  pages = {5106 [16 p.]},
  year = {2021},
  DOI = {10.3390/rs13245106},
  URL = {https://www.documentation.ird.fr/hor/{PAR}00023839},
}