Comparison of the ocean inherent optical properties obtained from measurements and inverse modeling

A model developed recently by Loisel and Stramski [Appl. Opt. 39, 3001-3011 (2000)] for estimating the spectral absorption a(lambda), scattering b(lam bda), and backscattering b(b)(lambda) coefficients in the upper ocean from the irradiance reflectance just beneath the sea surface R(lambda, z = 0(-)) and the diffuse attenuation of downwelling irradiance within the surface l ayer (K-d(lambda)), is compared with measurements. Field data for this comp arison were collected in different areas including off-shore and near-shore waters off southern California and around Europe. The a(lambda) and b(b)(l ambda) values predicted by the model in the blue-green spectral region show generally good agreement with measurements that covered a broad range of c onditions from clear oligotrophic waters to turbid coastal waters affected by river discharge. The agreement is still good if the model estimates of a (lambda) and b(b)(lambda) are based on R(lambda, z = 0(-)) used as the only input to the model available from measurements las opposed to both R(h, z = 0-) and (K-d(lambda))(1) being measured. This particular mode of operatio n of the model is relevant to ocean-color remote-sensing applications. In c ontrast to a(lambda) and b(b)(lambda) the comparison between the modeled an d the measured b(lambda) shows large discrepancies. These discrepancies are most likely attributable to significant variations in the scattering phase function of suspended particulate matter, which were not included in the d evelopment of the model. (C) 2001 Optical Society of America.