SCIATRAN - A new atmospheric radiative transfer model for the ultraviolet, visible, and near-infrared spectral regions

A new radiative transfer model has been developed mainly for retrieval of atmospheric constituents from the global nadir radiance measurements of the SCIAMACHY satellite spectrometer (spectral coverage: 240-2385 nm, spectral resolution: 0.2-1.6 nm). SCIATRAN solves the radiative transfer equation using the Finite Difference Method for a plane-parallel vertically inhomogeneous atmosphere taking into account multiple scattering. The present program version utilizes the pseudo-spherical approach including refraction to consider the sphericity of the Earth. SCIATRAN comprises, amongst others, the following features: (i) quasi-analytical calculation of weighting functions of atmospheric and surface parameters, (ii) DOAS airmass factor calculations, (iii) height resolved radiation fluxes, including actinc fluxes for photolysis rate calculations, (iv) inelastic rotational Raman scattering by N-2 and O-2 molecules, (v) parameterization schemes for aerosols and clouds, (vi) a line-by-line and a correlated-kappa distribution mode for line absorption, and (vii) thermal emission. SCIATRAN will be made available for non-commercial scientific applications.