Figure 6.

(a–c) 180° field-of-view photographs and (d–i) polarization patterns of Arctic foggy, clear and partly cloudy skies measured by full-sky imaging polarimetry in the blue (450 nm) part of the spectrum. (j–l) Patterns of the angle of polarization α (from the local meridian) calculated for the solar positions in patterns (a–i) on the basis of the Berry model, which can describe the polarization of the clear sky more accurately than the Rayleigh model [7]. In the α-patterns, white dots show the positions of the Sun (S), the Arago (A) and Babinet (B) neutral points.