Numerical modelling of spectral sky radiance during a total solar eclipse

Ground-based observations of the spectral sky radiance within the totality region during a total solar eclipse are of significant interest because the contribution from direct and single scattered light from the solar disk is eliminated. In the present paper, we develop a numerical model of the spectral sky radiance during totality, evaluate the contribution of double scattered sunlight to the sky radiance at totality and compare it to solar corona emissions. The results show that the single scattered coronal light is the major contaminant in ground-based observations of the corona, opposite to what was believed before. For observation directions outside the corona the double scattered sun radiation dominates over the single scattered coronal light.