Characterising top-of-atmosphere ultra-violet polarisation from radiative transfer calculations

Abstract

We have constructed a database of ultra-violet earthshine Stokes parameters for various solar and viewing geometries as well as surface albedos and atmospheric profiles, through radiative transfer modelling. For each atmospheric profile, we show that it is possible to parametrise certain aspects of the UV polarisation in solar zenith angle only. The effect of different total ozone columns can also be accounted for. These parametrisations lead to significant reductions in the radiance errors of polarisation sensitive instruments like GOME, GOME-2 and SCIAMACHY. This is important for the retrieval of data products like the ozone profile