EGUsphere

Copernicus Publications

Göttingen, Germany

10.5194/egusphere-2025-6549

Evaluation of stratospheric transport in three generations of Chemistry-Climate Models

Abalos

Marta

https://orcid.org/0000-0002-1267-5115

¹ Birner

Thomas

https://orcid.org/0000-0002-2966-3428

² Chrysanthou

Andreas

https://orcid.org/0000-0002-8670-5436

³ ⁴ ⁵ Davis

Sean

https://orcid.org/0000-0001-9276-6158

⁶ de la Cámara

Alvaro

https://orcid.org/0000-0002-8831-4789

¹ Dhomse

Sandip

https://orcid.org/0000-0003-3854-5383

⁷ ⁸ Garny

Hella

⁹ Hegglin

Michaela I.

¹⁰ ¹¹ ¹² Hubert

Daan

https://orcid.org/0000-0002-4365-865X

¹³ Ivaniha

Oksana

https://orcid.org/0000-0003-2897-2736

¹ Keeble

James

https://orcid.org/0000-0003-2714-1084

¹⁴ Linz

Marianna

https://orcid.org/0000-0002-3241-5062

¹⁵ Minganti

Daniele

https://orcid.org/0000-0001-6131-2794

¹³ Neu

Jessica

¹⁶ Plummer

David

https://orcid.org/0000-0001-8087-3976

¹⁷ Saunders

Laura

¹⁸ Shah

Kasturi

https://orcid.org/0000-0003-1245-5128

¹⁹ Stiller

Gabriele

https://orcid.org/0000-0003-2883-6873

²⁰ Tourpali

Kleareti

⁴ Waugh

Darryn

https://orcid.org/0000-0001-7692-2798

²¹ Abraham

Nathan Luke

https://orcid.org/0000-0003-3750-3544

²² ²³ Akiyoshi

Hideharu

https://orcid.org/0000-0001-6463-9004

²⁴ Chipperfield

Martyn P.

https://orcid.org/0000-0002-6803-4149

³ ²⁵ Jöckel

Patrick

https://orcid.org/0000-0002-8964-1394

⁹ Josse

Béatrice

²⁶ Morgenstern

Olaf

https://orcid.org/0000-0002-9967-9740

²⁷ Sukhodolov

Timofei

https://orcid.org/0000-0001-7100-738X

²⁸ Watanabe

Shingo

²⁹ ³⁰ Yamashita

Yousuke

https://orcid.org/0000-0002-6813-4668

²⁴

Department of Earth Physics and Astrophysics, Universidad Complutense de Madrid, Spain

Ludwig-Maximilians-University, Munich, Germany

School of Earth and Environment, University of Leeds, Leeds, UK

Laboratory of Atmospheric Physics, Aristotle University of Thessaloniki, Greece

Institute of Geosciences, Spanish National Research Council (IGEO-CSIC), Madrid, Spain

NOAA Chemical Sciences Laboratory, Boulder, CO USA

School of Earth and Environment, University of Leeds, Leeds, UK

National Centre for Earth Observation (NCEO), University of Leeds, Leeds, UK

Deutsches Zentrum für Luft- und Raumfahrt, Institut für Physik der Atmosphäre, Oberpfaffenhofen, Germany

Institute of Climate and Energy Systems - Stratosphere (ICE-4), Forschungszentrum Juelich, Juelich, Germany

Department of Meteorology, University of Reading, Reading, UK

Institute for Atmospheric and Environmental Research, University of Wuppertal, Wuppertal, Germany

Royal Belgian Institute for Space Aeronomy (BIRA-IASB), Brussels, Belgium

Lancaster University, Lancaster, UK

Reflective Emeryville, CA USA

NASA JPL, Pasadena, CA, USA

Climate Research Division, Environment and Climate Change Canada, Montréal, Canada

Department of Physics, University of Toronto, Canada

Department of Applied Mathematics and Theoretical Physics, University of Cambridge, UK

Karlsruhe Institute of Technology, Institute of Meteorology and Climate Research - Atmospheric Trace Gases and Remote Sensing, Karlsruhe, Germany

Johns Hopkins University, Baltimore, MD, USA

National Centre for Atmospheric Science, UK

Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK

National Institute for Environmental Studies, Tsukuba, Japan

National Centre for Earth Observation (NCEO), University of Leeds, Leeds, UK

Météo-France, CNRS, Univ. Toulouse, CNRM, Toulouse, France

Deutscher Wetterdienst, Offenbach, Germany

Physikalisch-Meteorologisches Observatorium Davos / World Radiation Center, Davos, Switzerland

Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokohama, Japan

Advanced Institute for Marine Ecosystem Change (WPI-AIMEC), Tohoku University, Sendai, Japan

13 01 2026

2026 1 61

2026

This work is licensed under the Creative Commons Attribution 4.0 International License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/4.0/

This article is available from https://egusphere.copernicus.org/preprints/2026/egusphere-2025-6549/

The full text article is available as a PDF file from https://egusphere.copernicus.org/preprints/2026/egusphere-2025-6549/egusphere-2025-6549.pdf

The representation of stratospheric transport in Chemistry-Climate Models (CCMs) is key for accurately reproducing and projecting the evolution of the ozone layer and other radiatively relevant trace gases. We evaluate stratospheric transport in CCMs that have participated in three model intercomparison initiatives (CCMVal-2, CCMI-1, and CCMI-2022) over the last ~15 years using modern satellite datasets and reanalyses. Key long-standing model biases persist across generations, with some worsening in recent simulations. Transport remains overly fast in the models, with a global mean age of air young bias of ~1 year for the CCMI-2022 median. It is argued that this bias could be associated with too fast tropical upwelling in the lower stratosphere, insufficient horizontal mixing and/or excessive vertical diffusion. In the springtime southern polar stratosphere, the final warming is delayed (~3 weeks), downwelling is underestimated (~25 %), and the depth of the ozone minimum is overestimated (~10 DU) on average in the most recent models. The tropopause is too high in all generations, and the tropical cold point tropopause is too warm in the latest generation (~1–2 K). Long-term trends in transport and over 1980–1999 are consistent across model generations and highlight the crucial role of ozone depletion in contributing to accelerate the Brewer-Dobson circulation and delaying the southern polar vortex breakdown.

Ministerio de Ciencia, Innovación y Universidades

PID2021-124772OB-I00