OSIRIS & GOMOS: Combining Observations of Stratospheric O3 and NO2

We present observations of stratospheric trace gases from the OSIRIS/Odin and GOMOS/Envisat instruments. OSIRIS measures scattered solar light in limb geometry over the illuminated hemisphere whereas GOMOS uses stellar occultation method. Although GOMOS measures over both night and day side of the globe, only night-time occultations has been used below 45~km in this study. The combination of day and night observations provided by the instruments gives us almost a full global coverage for ozone below 45~km. The OSIRIS and GOMOS instruments provide consistent ozone measurements as the relative difference of the mean profiles was found less to be than 5% between 20 and 45~km. These datasets offer also a possibility to study diurnal effects of ozone and NO2. The OSIRIS Level 2 data are processed using the so-called Modified Onion Peeling inversion method developed at FMI, and the GOMOS dataset used in this study is the last reprocessed version.