Intensity and Polarization line profiles in a semi-infinite Rayleigh-scattering planetary atmosphere. II. Variations of equivalent width over the disk

Abstract

The study of the variation of equivalent width in a Rayleighscattering planetary atmosphere along the intensity equator and along the mirror meridian on which μ =μ₀ shows that the equivalent widths decrease monotonically towards the poles, the limb and the terminator with the following characteristics: (i) the weakest lines exhibit the maximum change; (ii) the I^e_r component shows more change than the I^e_l component; (iii) the decrease towards the limb or the terminator is not as sharp as that towards the poles; (iv)I^e_l component shows more decrease towards the limb while I^e_r component shows more decrease towards the terminator; and (v) the relation W (μ,φ;μ₀,φ₀)= W (μ₀,φ₀;μ,φ) holds for the total intensity. These results are qualitatively in agreement with the observations of absorption bands in the spectra of Venus, Jupiter and Saturn.