In orange, the observations of the polarisation flux (top), DoLP (middle), and AoLP (bottom) at 620 ± 5 nm over 7 almucantars on February 27, 2020. The thickness of the line indicates the uncertainties). A sliding average of 10 s is applied. Black stars (★): model without aerosols (no Mie scattering) nor isotropic background (γ = 0). Red plus (+): idem but model with aerosols. Blue (×): same as red with an isotropic background set to fit the flux. The vertical dashed lines show the Skibotn direction.