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

Abstract

A model developed recently by Loisel and Stramski [Appl. Opt. 39, 3001-3011 (2000)] for estimating the spectral absorption a(lambda), scattering b(lambda), 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 layer ?K(d)(lambda)?(1) is compared with measurements. Field data for this comparison were collected in different areas including off-shore and near-shore waters off southern California and around Europe. The a(lambda) and b(b)(lambda) values predicted by the model in the blue-green spectral region show generally good agreement with measurements that covered a broad range of conditions 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 [as opposed to both R(lambda, z = 0(-)) and ?K(d)(lambda)?(1) being measured]. This particular mode of operation of the model is relevant to ocean-color remote-sensing applications. In contrast to a(lambda) and b(b)(lambda) the comparison between the modeled and 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 development of the model.

Automatic Sun Glint Removal of Multispectral High-Resolution Worldview-2 Imagery for Retrieving Coastal Shallow Water Parameters

“…where r m rs is the modeled subsurface reflectivity; r dp rs is the subsurface reflectivity of the deep water; ρ is the seafloor albedo; θś is the subsurface solar zenith angle; θv is the subsurface view angle; D c u and D b u are the optical path-elongation factors for scattered photons from the water column and the bottom; k d is the diffuse attenuation coefficient; and z is the depth [19][20][21][22].…”

A Semi-Analytical Model for Remote Sensing Retrieval of Suspended Sediment Concentration in the Gulf of Bohai, China

“…Then, the spectral radiances were inverted to simultaneously provide the IOPs values of in-water content on a pixel-by-pixel [37][38][39]. Loisel and Stramski et al [40,41] proposed a semi-analytical method based on the radiative transfer theory. Specifically, they used the irradiance reflectivity R (λ, 0 ) and the average vertical attenuation coefficient Kd (within the first optical depth) just beneath the water surface to retrieve the total absorption, scattering and backscattering coefficients.…”

Using satellite-derived backscattering coefficients in addition to chlorophyll data to constrain a simple marine biogeochemical model

“…LP Loisel and Stramski, 2000;Loisel et al, 2001.) b b (490) obtained from this algorithm is converted to b bp (490) using…”

“…Furthermore, b bp derived from satellite data has been empirically related to the amount of POC in the surface waters (e.g. Loisel et al, 2001Loisel et al, , 2002Stramski et al, 1999). POC is a combination of the amount of carbon contained within living phytoplankton (C P ) and biological detritus (C D ).…”