Uncertainty in the bidirectional reflectance model for oceanic waters

• Published in: Applied optics (2004) 2015-05, Vol.54 (13), p.4061-4069
• Main Authors: Zhai, Peng-Wang, Hu, Yongxiang, Trepte, Charles R, Winker, David M, Lucker, Patricia L, Lee, Zhongping, Josset, Damien B
• Format: Article
• Language: English
• Subjects: Absorption coefficient; Depolarization; Mathematical models; Oceans; Q factors; Radiance; Scattering coefficients; Uncertainty
• ISSN: 1559-128X; 2155-3165
• DOI: 10.1364/AO.54.004061

We study the impacts of the bio-optical model variations on the angular distribution (f/Q factor) of the upwelling radiance field in ocean waters. An ocean water bio-optical model has been combined with a vector radiative transfer model to calculate the f/Q factors systematically. The f/Q factors are compared to those in [Appl. Opt. 41, 6289 (2002) [CrossRef]] and the differences are found to be within + or -10% for 81% of the total number of cases covering all wavelengths, chlorophyll a concentrations, and solar and viewing geometries. The differences are attributed to the choice of ocean water scattering function and scattering coefficient biases. In addition, we study the uncertainty of f/Q factor due to three factors: (I) the absorption coefficient of the colored dissolved organic matter (CDOM), (II) the particle scattering coefficient, and (III) the ocean water depolarization. The impacts of ocean water depolarization on the f/Q variation is found to be negligible. If we perturb the CDOM absorption coefficient by a factor ranging from 0.1 to 10, the f/Q values vary within + or -5% of the average behavior of ocean waters for 93% of the cases. If we perturb the scattering coefficients by a factor ranging from 0.5 to 2.0, the f/Q variation is within + or -5% for 81% of the cases studied. This work contributes to understanding the uncertainty of ocean color remote sensing.