Comparing coincident SAGE III ISS measurements of stratospheric trace species with those measured by OSIRIS

The SAGE III instrument has been in operation on the International Space Station (ISS) for over one full year. During this time, they have collected occultation measurements and used these to infer vertical profiles of nitrogen dioxide, stratospheric aerosol and ozone. Validation of the SAGE III data quality is of keen interest to the stratospheric chemistry community and over the past 18 months much effort has been put into this endeavour. The OSIRIS instrument has been in operation on the Odin satellite since the autumn of 2001. Since then its measurements have been used to produce an almost two decade long, high quality data record of the three primary trace species measured by SAGE III ISS. These species are vertically resolved: ozone number density profiles; nitrogen dioxide number density profiles and stratospheric aerosol extinction profiles. Past comparison studies involving OSIRIS results and measurements made by SAGE II and SAGE III Meteor-3M have shown excellent agreement between these data records that all measure on the same native altitude grid, with comparable vertical resolutions. Therefore, the OSIRIS data record is an excellent candidate for SAGE III ISS data quality verification. This paper will present the most up to date SAGE III ISS cross comparisons with coincident OSIRIS measurements. It will also discuss how identified biases and drifts can be corrected so that the new SAGE III ISS measurements can be merged into existing ozone data records such as the SAGE II/IOSIRIS/OMPS-LP USask 2D time series that has contributed to the latest LOTUS Initiative report.