SCIAMACHY SOLAR AND LUNAR OCCULTATION: VALIDATION OF OZONE, NO2 AND NO3 PROFILES

Using a global spectra fitting method by the differential optical depth within the radiative transfer and retrieval code SCIATRAN 2.1, vertical profiles of stratospheric traces gases are derived from SCIAMACHY solar and lunar occultation transmission spectra. From solar occultation observations ozone and NO2 profiles have been retrieved, from lunar occultation measurements ozone, NO2, and NO3 profiles have been derived. To access the quality of the SCIAMACHY occultation retrieved products a validation study was carried out, by comparing the retrieved ozone and NO2 profiles to correlative observations of other satellite instruments. These instruments are the Halogen Occultation Experiment (HALOE), the second Stratospheric Aerosol and Gas Experiment (SAGE II), and The third Polar Ozone and Aerosol Measurement (POAM III) . The NO3 profiles are compared with results from a photochemical model scheme. The validation show good results for SCIAMACHY occultation products. In solar occultion, the deviation of ozone is mostly within 0% to +10% for ozone and within 20% for NO2 over a wide altitude range. In lunar occultation, the agreement is +10 ˙ % to +20% for ozone and within 20% for NO2 in the main part of the profiles. The NO3 results show good agreement with the model outputs within the accuracy of 35%.