On the improved stability of the version 7 MIPAS ozone record
Abstract. The Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) was an IR limb emission spectrometer on the Envisat platform. From 2002 to 2012, it performed pole-to-pole measurements during day and night, producing more than 1000 profiles/day. The European Space Agency (ESA) has recently released the new version 7 of Level 1 MIPAS spectra, in which a new set of time-dependent correction coefficients for the non-linearity in the detectors’ response functions was implemeted. This change is expected to reduce the long-term drift of the MIPAS Level 2 data. We evaluate the long-term stability of ozone level 2 data retrieved from MIPAS V7 Level 1 spectra with the IMK/IAA Scientific Level 2 Processor. We compare it with ozone measurements from the Microwave Limb Sounder (MLS) instrument on NASA’s Aura satellite, ozonesondes and ground-based lidar instruments. The ozonesondes and lidars alone do not allow us to conclude with enough significance that the new version is more stable than the previous one, but a clear improvement in long-term stability is observed in the satellite-data based drift analysis. The results of ozonesondes, lidars and satellite drift analysis are consistent: all indicate that the drifts of the new version are less negative/more positive nearly everywhere above 15 km. These results indicate that MIPAS data are now even more suited for trend studies, alone or as part of a merged data record.