NO2 and BrO vertical profile retrieval from SCIAMACHY limb measurements: Sensitivity studies

A retrieval algorithm used to obtain vertical distributions of NO2 and BrO from SCIAMACHY limb measurements is described. Furthermore, the information content of SCIAMACHY limb measurements with respect to NO2 and BrO profile retrievals is investigated. Another investigated aspect is a sensitivity of resulting NO2 and BrO vertical profiles to a priori trace gas vertical distributions as well as to the pressure and temperature profiles used in the forward modeling. The sensitivity region is estimated to be 12-40 km for NO2 and 12-35 km for BrO. Larger retrieval errors are encountered below 15 km associated to the influence of the neighboring altitude levels and of a priori information. The dependence of the retrieved trace gas vertical distributions on the pressure and temperature profiles used in the forward model is found to be insignificant above 20 km, whereas it cannot be completely ignored when retrieving trace gas amounts below.