Journal article

The influence of mixing on the stratospheric age of air changes in the 21st century

Roland Eichinger, Simone Dietmueller, Hella Garny, Petr Sacha, Thomas Birner, Harald Boenisch, Giovanni Pitari, Daniele Visioni, Andrea Stenke, Eugene Rozanov, Laura Revell, David A Plummer, Patrick Joeckel, Luke Oman, Makoto Deushi, Douglas E Kinnison, Rolando Garcia, Olaf Morgenstern, Guang Zeng, Kane Adam Stone Show all



Climate models consistently predict an acceleration of the Brewer-Dobson circulation (BDC) due to climate change in the 21st century. However, the strength of this acceleration varies considerably among individual models, which constitutes a notable source of uncertainty for future climate projections. To shed more light upon the magnitude of this uncertainty and on its causes, we analyse the stratospheric mean age of air (AoA) of 10 climate projection simulations from the Chemistry-Climate Model Initiative phase 1 (CCMI-I), covering the period between 1960 and 2100. In agreement with previous multi-model studies, we find a large model spread in the magnitude of the AoA trend over the simula..

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Awarded by Helmholtz Association

Awarded by Australian Research Council's Centre of Excellence for Climate System Science

Awarded by Australian Antarctic science grant programme

Awarded by Government of Spain

Awarded by GA CR

Awarded by New Zealand Royal Society Marsden Fund

Funding Acknowledgements

This study was funded by the Helmholtz Association under grant VH-NG-1014 (Helmholtz-Hochschul-Nachwuchsforschergruppe MACClim). We thank the modelling groups for making their simulations available for this analysis, the SPARC/IGAC Chemistry-Climate Model Initiative (CCMI) project for organising and coordinating the model data analysis activity and the British Atmospheric Data Centre (BADC) for collecting and archiving the CCMI model output. ACCESS-CCM runs were supported by the Australian Research Council's Centre of Excellence for Climate System Science (CE110001028), the Australian Government's National Computational Merit Allocation Scheme (q90) and the Australian Antarctic science grant programme (FoRCES 4012). We also acknowledge the project ESCiMo (Earth System Chemistry integrated Modelling), within which the EMAC simulations were conducted at the German Climate Computing Centre DKRZ through support from the Bundesministerium fur Bildung und Forschung (BMBF). Moreover, we acknowledge the UK Met Office for use of the MetUM. This research was supported by the NZ Governments Strategic Science Investment Fund (SSIF) through the NIWA programme CACV. The authors wish to acknowledge the contribution of NeSI high-performance computing facilities to the results of this research. New Zealand's national facilities are provided by the New Zealand eScience Infrastructure (NeSI) and funded jointly by NeSIs collaborator institutions and through the Ministry of Business, Innovation & Employments Research Infrastructure programme (, last access: May 2018). Petr Sacha was supported by the Government of Spain under grant no. CGL2015-71575-P and partly by GA CR under grant nos. 16-01562J and 18-01625S, and Olaf Morgenstern acknowledges funding by the New Zealand Royal Society Marsden Fund (grant 12-NIW-006). Moreover, we thank two anonymous referees for their helpful comments on the manuscript and Andreas Engel for providing the in situ AoA data.