Coherence of long-term stratospheric ozone vertical distribution time series used for the study of ozone recovery at a northern mid-latitude station
- ISSN: 16807316
- DOI: 10.5194/acp-11-4957-2011
The coherence of stratospheric ozone time series retrieved from various\nobservational records is investigated at Haute-Provence Observatory\n(OHP-43.93 degrees N, 5.71 degrees E). The analysis is accomplished\nthrough the intercomparison of collocated ozone measurements of Light\nDetection and Ranging (lidar) with Solar Backscatter UltraViolet(/2)\n(SBUV(/2)), Stratospheric Aerosol and Gas Experiment II (SAGE II),\nHalogen Occultation Experiment (HALOE), Microwave Limb Sounder (MLS) on\nUpper Atmosphere Research Satellite (UARS) and Aura and Global Ozone\nMonitoring by Occultation of Stars (GOMOS) satellite observations as\nwell as with in situ ozonesondes and ground-based Umkehr measurements\nperformed at OHP. A detailed statistical study of the relative\ndifferences of ozone observations over the whole stratosphere is\nperformed to detect any specific drift in the data. On average, all\ninstruments show their best agreement with lidar at 20-40 km, where\ndeviations are within +/- 5%. Discrepancies are somewhat higher below\n20 and above 40 km. The agreement with SAGE II data is remarkable since\naverage differences are within +/- 1% at 1741 km. In contrast, Umkehr\ndata underestimate systematically the lidar measurements in the whole\nstratosphere with a near zero bias at 16-8 hPa (similar to 30 km).\nDrifts are estimated using simple linear regression for the data sets\nanalysed in this study, from the monthly averaged difference time\nseries. The derived values are less than +/- 0.5% yr-1 in the 20-40 km\naltitude range and most drifts are not significant at the 2 sigma level.\nWe also discuss the possibilities of extending the SAGE II and HALOE\ndata with the GOMOS and Aura MLS data in consideration with relative\noffsets and drifts since the combination of such data sets are likely to\nbe used for the study of stratospheric ozone recovery in the future.