On the role of the seawater absorption-to-attenuation ratio in the radiance polarization above the southern Baltic surface
<p>Information about polarization of light leaving the ocean surface has the potential to improve the quality of bio-optical parameter retrieval from ocean color remote sensing (OCRS). This improvement can be applied in numerous ways, such as limiting of Sun glints and obtaining information ab...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2019-06-01
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| Series: | Ocean Science |
| Online Access: | https://www.ocean-sci.net/15/745/2019/os-15-745-2019.pdf |
| Summary: | <p>Information about polarization of light leaving the ocean surface
has the potential to improve the quality of bio-optical parameter
retrieval from ocean color remote sensing (OCRS). This improvement can be
applied in numerous ways, such as limiting of Sun glints and obtaining
information about atmospheric aerosol properties for atmospheric correction
as well as increasing the accuracy of the algorithms based on the
water-leaving signal. Polarization signals at the top of the atmosphere (ToA)
that include the water-leaving signal are strongly influenced by atmospheric
molecular scattering and by direct Sun and sky reflections from the sea
surface. For these reasons, it is necessary to better understand the factors
that change the polarization of light in the atmosphere–ocean system,
especially in coastal zones affected by dynamic changes. In this paper, the
influence of seasonal variability of light absorption and scattering
coefficients (inherent optical properties; IOPs) of seawater, wind speed and
solar zenith angle (SZA) on the polarization of upwelling radiance over the
sea surface in the visible light bands is discussed. The results come from a
polarized radiative transfer model based on the Monte Carlo code and applied
to the atmosphere–ocean system using averaged IOPs as input data. The
results, presented in the form of polar plots of the total upwelling radiance
degree of polarization (DoP), indicate that regardless of the wavelength of
light and type of water, the highest value of the above-water DoP is strongly
correlated with the absorption-to-attenuation ratio. The correlation is a
power function that depends on both the SZA and the wind speed. The
correlation versatility for different wavelengths of light is very unusual in
optics of the sea and is therefore worth emphasizing.</p> |
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| ISSN: | 1812-0784 1812-0792 |