Accurate and self-consistent ocean color algorithm: simultaneous retrieval of aerosol optical properties and chlorophyll concentrations

Abstract

A new algorithm has been developed for simultaneous retrieval of aerosol optical properties and chlorophyll concentrations in case I waters. This algorithm is based on an improved complete model for the inherent optical properties and accurate simulations of the radiative transfer process in the coupled atmosphere-ocean system. It has been tested against synthetic radiances generated for the Sea-Viewing Wide Field-of-View Sensor (SeaWiFS) channels and has been shown to be robust and accurate. A unique feature of this algorithm is that it uses the measured radiances in both near-IR and visible channels to find that combination of chlorophyll concentration and aerosol optical properties that minimizes the error across the spectrum. Thus the error in the retrieved quantities can be quantified.

Using MERIS full resolution data to monitor coastal waters — A case study from Himmerfjärden, a fjord-like bay in the northwestern Baltic Sea

“…Another attempt to solve the atmospheric correction is the neural network approach described by Schroeder et al (2002). There are also several coupled ocean-atmosphere models in development that include both an atmospheric correction model, as well as a bio-optical in-water model that can be tuned to local conditions (Moore et al, 1999;Stamnes et al, 2003;Lavender et al, 2005). …”

Improving Remote Sensing of Aerosol Optical Depth over Land by Polarimetric Measurements at 1640 nm: Airborne Test in North China

“…The superscripts m and a represent molecules and aerosols, respectively. The coefficients ψ and ζ account for diffuse transmission contributions of light from aerosols and molecules, which are not accounted for in Equation (3). ψ is equal to 0.9. ζ depends on the aerosol model.…”

“…This separation is critical to obtain accurate aerosol parameters. The retrieval of aerosols over the ocean, on which the surface is dark enough, can be reasonably estimated in terms of the variability of chlorophyll concentration [2,3]. However, aerosol retrieval over land surfaces is much more difficult, because the aerosol contribution is generally smaller than that of the surface, and the surface albedo strongly depends on the land surface type and vegetation coverage.…”

Simultaneous determination of aerosol optical thickness and water leaving radiance from multispectral measurements in coastal waters

“…In the past decades, other feasible methods using a direct optimization-based inversion algorithm (Bricaud and Morel, 1987;Doerffer and Fischer, 1994;Zhao and Nakajima, 1997;Chomko and Gordon, 1998;Stamnes et al, 2003;Dubovik et al, 2008;Li et al, 2008;Kuchinke et al, 2009;Shi et al, 2016;Fan et al, 2017) or Bayesian methodology (Frouin and Pelletier, 2015) have been developed to complement prevailing atmospheric correction schemes. These one-step retrieval approaches involve a direct inversion scheme that simultaneously determines aerosols and oceanic substances with 10 minimal assumption, which have an advantage in dealing flexibly with the inversion problems in the absorption aerosol loading conditions and increasing the available measurements information content.…”