Single-wavelength algorithms for in situ or remote sensing estimation of mean pigment concentration

The bio-optical relationships between inherent and apparent optical properties, and between optical properties and phytoplankton pigment concentration (C) averaged in a layer (ΔZ), were derived from analysis of data collected during the period 1996–1998 in the Gulf of Aqaba (Eilat). Parametrization of these relationships was based on radiative transfer theory, Gershun's equation, minimization of model errors by least-square fitting, and on known optical models relating underwater remote sensed reflectance (Rrsw) with the ratio of backscattering (bb) to vertical attenuation coefficient (Kd) [or to absorption coefficient (a)]. These relationships explain a frequently used form of remote sensing algorithms for C estimation using ratio of water-leaving radiances measured at two or more wavelengths (λ). In this study, the possibility of using for this purpose a single wavelength in the blue range (λ=443 nm) within the framework of in situ and remote sensing algorithms for Case 1 waters was assessed.