A dynamics-based separation of deep and shallow stratospheric circulation branches

Baikhadzhaev, Rasul; Ploeger, Felix; Preusse, Peter; Ern, Manfred; Birner, Thomas

doi:https://doi.org/10.5194/acp-25-12753-2025

Articles | Volume 25, issue 19

https://doi.org/10.5194/acp-25-12753-2025

© 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-25-12753-2025

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

Articles | Volume 25, issue 19

Research article

|

12 Oct 2025

Research article |

| 12 Oct 2025

A dynamics-based separation of deep and shallow stratospheric circulation branches

Rasul Baikhadzhaev, Felix Ploeger, Peter Preusse, Manfred Ern, and Thomas Birner

Data sets

ERA5 hourly data on single levels from 1940 to present Copernicus Climate Change Service https://doi.org/10.24381/cds.adbb2d47

The JRA-55 Reanalysis: General specifications and basic characteristics Kobayashi et al. https://doi.org/10.5065/D6HH6H41

The Modern-Era Retrospective Analysis for Research and Applications, Version 2 (MERRA-2) Gelaro et al. https://doi.org/10.5067/WWQSXQ8IVFW8

Short summary

Across four reanalyses, the shallow branch of the stratospheric overturning circulation was found to be driven by planetary waves 1 to 3, and the deep branch of the circulation was found to be driven by smaller-scale waves (wave 4 and higher). However, the height of the level separating the branches is dependent on the reanalysis considered. Thus, using the appropriate separation levels in model inter-comparisons could reduce the spread between models regarding climatology and trends in the circulation.