Assessing Uncertainties in Satellite Ocean Color Bio-Optical Properties

Uncertainties in retrievals of bio-optical properties from satellite ocean color imagery are related to a variety of factors, including errors associated with sensor calibration and degradation, atmospheric correction, and the bio-optical inversion algorithms. Here we examine the impact of uncertainties in the top-of-atmosphere (TOA) radiances and coefficients in the quasi-analytical algorithm (QAA) on the satellite estimation of the normalized water-leaving radiances (nLw) and downstream bio-optical properties, such as the absorption and backscattering coefficients and chlorophyll. We use a Moderate Resolution Imaging Spectroradiometer (MODIS) image, free from clouds, covering the Gulf of Mexico, as our data set. We apply ensembles at each pixel in the image to simulate noise on the satellite TOA radiance values (randomly-distributed in the range of + or - 2.0%) at MODIS visible and near-infrared wavelengths. We also use ensembles to analyze sensitivity of coefficients in the QAA algorithm to quantify the impact of uncertainties on absorption and backscattering coefficients.
Presented at Ocean Optics XXI, Glasgow, Scotland, 8-12 October, 2012.