Project C05:
Transport processes regulating the lowermost stratospheric ozone reservoir

Brief Summary

The ozone reservoir in the lowermost stratosphere (LMS) greatly affects the potential for ozone to be transported downward into the troposphere and eventually to the surface where it has detrimental effects on human health. This project seeks to quantify transport of ozone into the LMS and thereby improve our understanding of the ozone budget of the LMS. Our central questions are: which transport processes regulate the ozone reservoir in the LMS, what is their relative strength, and how do they vary on seasonal and interannual time scales? For this purpose we will carry out a budget analysis of LMS ozone based on modern reanalyses, study the variability of individual budget terms and evaluate their contributions to events of reduced versus enhanced LMS ozone.
These budget analyses will be combined with observational analyses of ozone based on data sets from different observational platforms (particularly IAGOS-CARIBIC, HALO missions, satellites) as well as transport analyses and trajectories from the ClaMS model. The observational analyses will be carried out using a coordinate framework that takes into account major transport barriers (tropopause-relative, jet core-relative) to reduce the variability induced by quasi-reversible dynamical processes. Based on the observational tracer data and interpolated reanalysis data along the flighttrack an observational based air mass budget for the LMS will be determined and appllied to observed and reanalysis ozone data. Using the combined observational and renalysis data we will further address the question of reversible versus irreversible ozone transport by intrusions into the troposphere.

Members

Publications

Ploeger, F., T. Birner, E. Charlesworth, P. Konopka, and R. Müller (2024): Moist bias in the Pacific upper troposphere and lower stratosphere (UTLS) in climate models affects regional circulation patterns. Atmospheric Chemistry and Physics 24 (3), 2033–2043. doi: https://doi.org/10.5194/acp-24-2033-2024.

Charlesworth, E., F. Ploeger, T. Birner, R. Baikhadzhaev, M. Abalos, L. Abraham, H. Akiyoshi, S. Bekki, F. Dennison, P. Jöckel, J. Keeble, D. Kinnison, O. Morgenstern, D. Plummer, E. Rozanov, S. Strode, G. Zeng, and M. Riese (2023): Stratospheric water vapor affecting atmospheric circulation. 14, doi: https://doi.org/10.1038/s41467-023-39559-2.

Harzer, F., H. Garny, F. Ploeger, H. Bönisch, P. Hoor, and T. Birner (2023): On the pattern of interannual polar vortex-ozone co-variability during northern hemispheric winter. Atmospheric Chemistry and Physics 23 (18), 10661–10675. doi: 10.5194/acp-23-10661-2023.

Boljka, L. and T. Birner (2022): Potential impact of tropopause sharpness on the structure and strength of the general circulation. npj Climate and Atmospheric Science 5, (1), 2397–3722. doi: https://doi.org/10.1038/s41612-022-00319-6.