MODIS Chlorophyll Algorithm Semi-analytical algorithm (1) Chl_a = 10**(0.283 - 2.753*R + 1.457*R 2 + 0.659*R 3 - 1.403*R 4 ) where: R = log10((Rrs443 > Rrs488) / Rrs551) Rrs = nLw / F0; remote sensing reflectance F0 = extraterrestrial solar irradiance nLw = water leaving radiance at 443, 488, 551 (1) Performance of the MODIS Semi-analytical Ocean Color Algorithm for Chlorophyll-a Carder, K.L.; Chen, F.R.; Cannizzaro, J.P.; Campbell, J.W.; Mitchell, B.G.