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Updated: Jun 14, 2026
11:34
Scattering And Absorption of Light in Planetary Regoliths
Published on: July 1, 2019
Summary
Twilight polarization and color ratio data reveal how cloud shadows and haze alter atmospheric light scattering. Earth
Area of Science:
- Atmospheric optics
- Aerosol science
- Remote sensing
Background:
- Coulson's twilight data from Mauna Loa Observatory provides insights into atmospheric light scattering.
- Observed deviations from clear-sky averages require explanation.
- Stratospheric aerosol's role in polarization minima is a key area of interest.
Purpose of the Study:
- To reinterpret twilight zenith polarization and color ratio (CR) data.
- To explain deviations from clear-sky averages by considering the Earth's shadow.
- To investigate the influence of aerosols and atmospheric conditions on polarization patterns.
Main Methods:
- Reanalysis of existing zenith polarization and color ratio (CR) data.
- Modeling the effect of Earth's shadow elevation by clouds or haze.
- Comparison with historical data from different geographical locations (Germany).
Main Results:
- Moderate shadow lift reduces red/green CR; greater lift shifts CR peak to smaller solar depression.
- Shadow lift causes slight polarization reduction (moderate) or shifts polarization minimum (large lift).
- Tropical aerosol layers and tropospheric conditions explain differences in polarization minima compared to Germany.
Conclusions:
- Earth's shadow elevation by clouds/haze significantly impacts twilight optical measurements.
- Stratospheric aerosol properties and tropospheric conditions are crucial for understanding polarization patterns.
- Tropical atmospheric conditions lead to distinct polarization characteristics compared to mid-latitudes.
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