Towards O3 and NO2 vertical profile retrieval from SCIAMACHY solar occultation measurements: first results Original Research Article

SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY) is a space-borne instrument, which measures in the UV–Vis–IR range in nadir, limb, and occultation geometry. It has successfully been launched onboard ENVISAT (ENVIronmental SATellite) on March 1 2002. During the six month commissioning phase of ENVISAT, first test retrievals using uncalibrated Level 0 data were performed. We retrieved O3 and NO2 height resolved profiles with considerable accuracy and compared them to POAM III and SAGE III results. Tangent heights were calculated by O2 and CO2 retrievals. The retrieval is based on the optimal estimation method. The spectral fits of O3 and NO2 absorption spectra were analysed and the fit residues show remaining spectral inhomogeneities of the solar disk and instrumental features. An algorithm has been developed to minimise the impact of the solar inhomogeneities.