Estimation of phytoplankton pigment concentration in the Gulf of Aqaba (Eilat) by in situ and remote sensing single-wavelength algorithms

Bio-optical relationships between inherent and apparent optical properties, and between optical properties and phytoplankton pigment concentration (C) averaged in a discrete layer, were developed. These relationships were derived from analysis of data collected during the period 1996-1998 in the Gulf of Aqaba (Eilat), a 'Case 1' type water body. Parameterization of these relationships was accomplished by combining Gershun's equation, radiative transfer theory for average cosine of underwater light field, and a set of different bio-optical models. An analysis of the asymptotic light field was carried out. Semi-analytical single-wavelength (at λ=443 nm) algorithms for in situ and remote sensing (RS) estimation of mean pigment concentration were developed, and evaluated by sensitivity and error analysis. The advantages of RS single-wavelength algorithms in comparison with current two- and multi-wavelengths RS algorithms are discussed.