Long-term changes in the thermodynamic structure of the lowermost stratosphere inferred from reanalysis data

Weyland, Franziska; Hoor, Peter; Kunkel, Daniel; Birner, Thomas; Plöger, Felix; Turhal, Katharina

doi:https://doi.org/10.5194/acp-25-1227-2025

Articles | Volume 25, issue 2

https://doi.org/10.5194/acp-25-1227-2025

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

Special issue:

The SPARC Reanalysis Intercomparison Project (S-RIP) Phase...

https://doi.org/10.5194/acp-25-1227-2025

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

Articles | Volume 25, issue 2

Research article

|

29 Jan 2025

Research article |

| 29 Jan 2025

Long-term changes in the thermodynamic structure of the lowermost stratosphere inferred from reanalysis data

Franziska Weyland, Peter Hoor, Daniel Kunkel, Thomas Birner, Felix Plöger, and Katharina Turhal

Data sets

The mass of the lowermost stratosphere (LMS): LMS mass calculation and trends in five reanalyses for the time period 1979–2019 Franziska Weyland https://doi.org/10.5281/zenodo.13890232

JRA-55: Japanese 55-year Reanalysis, Monthly Means and Variances Japan Meteorological Agency/Japan https://doi.org/10.5065/D60G3H5B

MERRA-2 instM_3d_asm_Np: 3d,Monthly mean,Instantaneous,Pressure-Level,Assimilation,Assimilated Meteorological Fields V5.12.4 Global Modeling And Assimilation Office and S. Pawson https://doi.org/10.5067/2E096JV59PK7

Near real-time monthly mean Japanese Reanalysis for Three Quarters of a Century (JRA-3Q) Japan Meteorological Agency/Japan https://doi.org/10.5065/CW01-2282

Complete ERA5 from 1940: Fifth generation of ECMWF atmospheric reanalyses of the global climate H. Hersbach et al. https://doi.org/10.24381/cds.143582cf

Model code and software

justinalsing/dlmmc: Second release (v1.1) J. Alsing and A. Smith https://doi.org/10.5281/zenodo.2660704

The mass of the lowermost stratosphere (LMS): LMS mass calculation and trends in five reanalyses for the time period 1979–2019 F. Weyland https://doi.org/10.5281/zenodo.13890232

Short summary

The lowermost stratosphere (LMS) plays an important role in the Earth's climate, containing strong gradients of ozone and water vapor. Our results indicate that the thermodynamic structure of the LMS was changing between 1979–2019 in response to anthropogenic climate change and the recovery of stratospheric ozone, also indicating large-scale circulation changes. We find that both the upper and the lower LMS boundaries show an (upward) trend, which has implications for the LMS mass.