The extratropical tropopause – trace gas perspective on tropopause definition choice

Bauchinger, Sophie; Engel, Andreas; Jesswein, Markus; Keber, Timo; Bönisch, Harald; Obersteiner, Florian; Zahn, Andreas; Emig, Nicolas; Hoor, Peter; Lachnitt, Hans-Christoph; Weyland, Franziska; Ort, Linda; Schuck, Tanja J.

doi:https://doi.org/10.5194/acp-25-14167-2025

Articles | Volume 25, issue 21

https://doi.org/10.5194/acp-25-14167-2025

© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.

Special issue:

The tropopause region in a changing atmosphere (TPChange)...

https://doi.org/10.5194/acp-25-14167-2025

© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 25, issue 21

Research article

|

30 Oct 2025

Research article |

| 30 Oct 2025

The extratropical tropopause – trace gas perspective on tropopause definition choice

Sophie Bauchinger, Andreas Engel, Markus Jesswein, Timo Keber, Harald Bönisch, Florian Obersteiner, Andreas Zahn, Nicolas Emig, Peter Hoor, Hans-Christoph Lachnitt, Franziska Weyland, Linda Ort, and Tanja J. Schuck

Data sets

IAGOS-CARIBIC whole air sampler data (v2024.01.12) T. Schuck and F. Obersteiner https://doi.org/10.5281/zenodo.10495039

IAGOS-CARIBIC MS files collection (v2024.10.28) A. Zahn et al. https://doi.org/10.5281/zenodo.14000090

Mission PHILEAS (Probe High Latitude Export of Air from the Asian Summer Monsoon) HALO https://halo-db.pa.op.dlr.de

Consistent meteorological (ERA5) and chemical (CLaMS) information across airborne measurements over the globe between 1997 and 2023 H. C. Lachnitt https://doi.org/10.5281/zenodo.15076519

Short summary

We compared different ways to define the upper barrier of the troposphere in the extra-tropics, the “tropopause”. By analysing ozone distributions sorted by different definitions, we found that the traditional temperature-based tropopause works less well than dynamic or tracer-based definitions. We saw a sharper transition of ozone across the tropopause using a higher value of potential vorticity than often used and recommend this value for future studies of exchange processes in this region.