Open AccessVariability of the reflectance coefficient of skylight from the ocean surface and its implications to ocean color
Author(s) -
Alexander Gilerson,
Carlos Carrizo,
Robert Foster,
Tristan Harmel
Publication year - 2018
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.26.009615
Subject(s) - radiance , remote sensing , ocean color , zenith , environmental science , radiative transfer , radiometry , satellite , atmospheric correction , seawifs , skylight , aeronet , aerosol , spectral bands , atmospheric optics , atmosphere (unit) , atmospheric radiative transfer codes , optics , meteorology , reflectivity , geology , physics , geography , chemistry , phytoplankton , organic chemistry , archaeology , astronomy , nutrient
The value and spectral dependence of the reflectance coefficient (ρ) of skylight from wind-roughened ocean surfaces is critical for determining accurate water leaving radiance and remote sensing reflectances from shipborne, AERONET-Ocean Color and satellite observations. Using a vector radiative transfer code, spectra of the reflectance coefficient and corresponding radiances near the ocean surface and at the top of the atmosphere (TOA) are simulated for a broad range of parameters including flat and windy ocean surfaces with wind speeds up to 15 m/s, aerosol optical thicknesses of 0-1 at 440nm, wavelengths of 400-900 nm, and variable Sun and viewing zenith angles. Results revealed a profound impact of the aerosol load and type on the spectral values of ρ. Such impacts, not included yet in standard processing, may produce significant inaccuracies in the reflectance spectra retrieved from above-water radiometry and satellite observations. Implications for satellite cal/val activities as well as potential changes in measurement and data processing schemes are discussed.