Abstract

Results are presented in several wavelengths of the sky intensity and polarization along the solar vertical at twilight, as calculated using the backward Monte Carlo method applied to spherical shell atmospheres. Molecular scattering with anisotropy of molecules, ozone absorption, and refraction are taken into account. The dependence of the intensity on the solar depression angle is in general agreement with calculations based upon single plus second order scattering, but the degree of polarization is much higher. It is verified that the molecular plus ozone atmosphere does not explain the purple light. The elongation of the Babinet neutral point from the sun is determined as a function of solar depression angle.

© 1974 Optical Society of America

Backward Monte Carlo Calculations of the Polarization Characteristics of the Radiation Emerging from Spherical-Shell Atmospheres

Dave G. Collins, Wolfram G. Blättner, Michael B. Wells, and Henry G. Horak
Appl. Opt. 11(11) 2684-2696 (1972)

Characteristics of skylight at the zenith during twilight as indicators of atmospheric turbidity. 2: Intensity and color ratio

Kinsell L. Coulson
Appl. Opt. 20(9) 1516-1524 (1981)

Atmospheric ozone and colors of the Antarctic twilight sky

Raymond L. Lee, Jr., Wolfgang Meyer, and Götz Hoeppe
Appl. Opt. 50(28) F162-F171 (2011)

Antitwilight II: Monte Carlo simulations

Steven C. Richtsmeier, David K. Lynch, and David S. P. Dearborn
Appl. Opt. 56(19) G169-G178 (2017)

Explanation of the Brightness and Color of the Sky, Particularly the Twilight Sky

E. O. Hulburt
J. Opt. Soc. Am. 43(2) 113-118 (1953)