An optical model for deriving the spectral particulate backscattering coefficients in clear and turbid coastal waters

An optical model is developed based on the diffuse attenuation coefficient (Kd) to estimate particulate backscattering coefficients bbp(λ) in clear and turbid coastal waters. A large in-situ data set is used to establish robust relationships between bbp(530) and bbp(555) and Kd(490) using an efficient nonlinear least square method which uses the Trust-Region algorithm with Bisquare weights scheme to adjust the coefficients. These relationships are obtained with good correlation coefficients (R2 = 0.786 and 0.790), low Root Mean Square Error (RMSE = 0.00076 and 0.00072) and 95% confidence bounds. The new model is tested with two independent data sets such as the NOMAD SeaWiFS Match-ups and OOXIX IOP algorithm workshop evaluation data set (Version 2.0w APLHA). Results show that the new model makes good retrievals of bbp at all key wavelengths (from 412–683 nm), with statistically significant improvements over other inversion models. Thus, the new model has the potential to improve our knowledge of particulate matters and their optical variability in both clear and turbid coastal waters.