Validation of ozone profiles from GOME satellite data

Ozone profiles on a global scale can be derived from GOME satellite data by minimizing the difference between the measured and the corresponding simulated spectra as a function of the vertical distribution of O-3 For this purpose the FU11 Retrieval Method (FURM) was developed, which is based on the optimal estimation approach and contains the radiative transfer code GOMETRAN as an essential component. The quality of the GOME ozone profiles is assessed by comparing them with coincident ozonesonde, lidar, and SAGE II measurements. The comparison results show good agreement at midlatitudes in winter and spring. For measurements performed at low solar zenith angles GOME tends to overestimate the ozone content at the altitude of the ozone maximum and above. This systematic effect is most probably due to errors in the radiometric calibration of the GOME spectra.