EGU23-13119
https://doi.org/10.5194/egusphere-egu23-13119
EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Are trends in total ozone consistent with stratospheric ozone trends from satellite observations? Are trends in total ozone consistent with stratospheric ozone trends from satellite observations?

Mark Weber1, Carlo Arosio1, Alexei Rozanov1, John P. Burrows1, Viktoria Sofieva2, Melanie Coldewey-Egbers3, Diego Loyola3, Vitali Fioletov4, Stacey M. Frith5, and Jeannette D. Wild6
Mark Weber et al.
  • 1University of Bremen, Institute of Environmental Physics (IUP), FB1, Bremen, Germany (weber@uni-bremen.de)
  • 2Finnish Meteorological Institute (FMI), Helsinki, Finland
  • 3German Aerospace Center (DLR), Oberpfaffenhofen, Germany
  • 4Environment and Climate Canada, Toronto, Canada
  • 5Science Systems and Applications Inc., Lanham, MD, USA
  • 6CISESS/ESSIC, UMD, College Park, MD, USA

Total ozone is a measure of the protection of the biosphere from UV radiation. Extratropical total ozone recovery trends of about +0.5%/decade are consistent with the continuous decline in stratospheric halogen loading since the middle 1990s as a consequence of the Montreal Protocol and its Amendments on phasing out ODS. Nevertheless, the recovery (or chemistry-related) trends in the northern hemisphere (NH) are compensated by changes in atmospheric dynamics leading to stable ozone levels since about 2000 (apart from year-to-year variability). The near-global (60°S-60°N) average total ozone level is currently about 2-3% below the 1964-1980 mean.

Lower stratospheric ozone, the dominating contributor to the total ozone column and derived from limb satellite observations, shows globally (below 60° latitude) a slightly negative (but mostly statistically insignificant) trend of about -1.5%/decade since 2000, which is not consistent with the stable total ozone levels in the NH.  Some studies suggested that increases in tropospheric ozone compensate for negative lower stratospheric trends leading to stable column levels. The trend regression models applied to ozone profiles and total ozone also differ. For instance, proxies representing changes in atmospheric dynamics and transport have been included for total ozone, but not for ozone profiles, which may also lead to inconsistencies between total and stratospheric column trends.

This presentation will report updated total ozone trends from five merged total ozone datasets up to 2022. The same regression model, including proxies representing atmospheric dynamics and transport, will be then applied to ozone profiles from the merged limb dataset (SAGE II-SCIAMACHY-OMPS) to evaluate the consistency between column and profile trends.

How to cite: Weber, M., Arosio, C., Rozanov, A., Burrows, J. P., Sofieva, V., Coldewey-Egbers, M., Loyola, D., Fioletov, V., Frith, S. M., and Wild, J. D.: Are trends in total ozone consistent with stratospheric ozone trends from satellite observations? Are trends in total ozone consistent with stratospheric ozone trends from satellite observations?, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-13119, https://doi.org/10.5194/egusphere-egu23-13119, 2023.