Validation of an improved European long-term multi-sensor total ozone record as part of the ESA Climate Change Initiative

The European Space Agency’s [ESA] Ozone Climate Change Initiative [CCI] project aims at producing and characterizing a number of high quality ozone data products generated from multiple satellite sensors. Improved Level-2 total ozone data sets based on the European sensors GOME/ERS-2, SCIAMACHY/Envisat and GOME-2/MetOp-A covering more than 17 years have recently been released. GOME-type Direct FITting [GODFIT] provides consistent results for all three sensors which are manifested via a similar seasonality, albeit with reduced amplitude, and similar solar zenith angle dependency. The validation of total ozone columns hence demonstrates a high level of inter-sensor consistency and an excellent long-term stability of individual instruments. One concludes that the accuracy of the CCI total ozone data sets is at the percent level during the complete time period from 1996 until 2012