Preprints
https://doi.org/10.5194/egusphere-2023-326
https://doi.org/10.5194/egusphere-2023-326
30 Mar 2023
 | 30 Mar 2023

Stratospherically induced tropospheric circulation changes under the extreme conditions of the No-Montreal-Protocol scenario

Franziska Zilker, Timofei Sukhodolov, Gabriel Chiodo, Marina Friedel, Tatiana Egorova, Eugene Rozanov, Jan Sedlacek, Svenja Seeber, and Thomas Peter

Abstract. The Montreal Protocol and its amendments (MPA) have been a huge success in preserving the stratospheric ozone layer from being destroyed by unabated chlorofluorocarbons (CFCs) emissions. The phase out of CFCs has not only prevented serious impacts on our health and climate, but also avoided strong alterations of atmospheric circulation patterns. With the Earth System Model SOCOLv4, we study the dynamical and climatic impacts of a scenario with unabated CFC emissions by 2100, disentangling radiative and chemical (ozone-mediated) effects of CFCs. In the stratosphere, chemical effects of CFCs (i.e. the resulting ozone loss) are the main drivers of circulation changes, weakening wintertime polar vortices and speeding up the Brewer-Dobson circulation. These dynamical impacts during wintertime are due to low-latitude ozone depletion and resulting reduction of the equator-to-pole temperature gradient. In Southern Hemisphere (SH) summer, the vortex strengthens, similar due to the effects of the Antarctic ozone hole over the second half of the 20th century. Furthermore, the winter and spring vortex variability increases in the SH, whereas it decreases in summer and fall. This seasonal variation of wind speed in the stratosphere has regional implications on the tropospheric circulation modes. We find coherent changes in the troposphere, such as negative Southern Annular mode (SAM) and North Atlantic Oscillation (NAO) during seasons with a weaker vortex (winter and spring); the opposite occurs during seasons with stronger westerlies in the stratosphere (summer). In the troposphere, radiative heating by CFCs prevails throughout the year, shifting the SAM into a positive phase and canceling out the ozone-induced effects on the NAO. Furthermore, global warming is amplified by 1.9 K with regionally up to 12 K increase over Eastern Canada and Western Arctic. Our study sheds light into the adverse effects of a non-adherence to the MPA on the global atmospheric circulation, uncovering the roles of the underlying physical mechanisms. In so doing, our study emphasizes the importance of the MPA for Earth’s climate, to avoid regional amplifications of negative climate impacts.

Journal article(s) based on this preprint

24 Oct 2023
Stratospherically induced circulation changes under the extreme conditions of the no-Montreal-Protocol scenario
Franziska Zilker, Timofei Sukhodolov, Gabriel Chiodo, Marina Friedel, Tatiana Egorova, Eugene Rozanov, Jan Sedlacek, Svenja Seeber, and Thomas Peter
Atmos. Chem. Phys., 23, 13387–13411, https://doi.org/10.5194/acp-23-13387-2023,https://doi.org/10.5194/acp-23-13387-2023, 2023
Short summary

Franziska Zilker et al.

Interactive discussion

Status: closed

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on egusphere-2023-326', Anonymous Referee #1, 04 Apr 2023
    • AC2: 'Reply on RC1', Franziska Zilker, 22 Jun 2023
  • RC2: 'Comment on egusphere-2023-326', Anonymous Referee #2, 21 Apr 2023
    • AC1: 'Reply on RC2', Franziska Zilker, 22 Jun 2023

Interactive discussion

Status: closed

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on egusphere-2023-326', Anonymous Referee #1, 04 Apr 2023
    • AC2: 'Reply on RC1', Franziska Zilker, 22 Jun 2023
  • RC2: 'Comment on egusphere-2023-326', Anonymous Referee #2, 21 Apr 2023
    • AC1: 'Reply on RC2', Franziska Zilker, 22 Jun 2023

Peer review completion

AR: Author's response | RR: Referee report | ED: Editor decision | EF: Editorial file upload
AR by Franziska Zilker on behalf of the Authors (22 Jun 2023)
EF by Vitaly Muravyev (26 Jun 2023)  Manuscript   Author's response   Author's tracked changes 
ED: Publish subject to minor revisions (review by editor) (18 Jul 2023) by Peter Haynes
AR by Franziska Zilker on behalf of the Authors (28 Jul 2023)  Author's response   Author's tracked changes   Manuscript 
ED: Publish as is (10 Aug 2023) by Peter Haynes
AR by Franziska Zilker on behalf of the Authors (17 Aug 2023)  Manuscript 

Post-review adjustments

AA: Author's adjustment | EA: Editor approval
AA by Franziska Zilker on behalf of the Authors (06 Oct 2023)   Author's adjustment   Manuscript
EA: Adjustments approved (07 Oct 2023) by Peter Haynes

Journal article(s) based on this preprint

24 Oct 2023
Stratospherically induced circulation changes under the extreme conditions of the no-Montreal-Protocol scenario
Franziska Zilker, Timofei Sukhodolov, Gabriel Chiodo, Marina Friedel, Tatiana Egorova, Eugene Rozanov, Jan Sedlacek, Svenja Seeber, and Thomas Peter
Atmos. Chem. Phys., 23, 13387–13411, https://doi.org/10.5194/acp-23-13387-2023,https://doi.org/10.5194/acp-23-13387-2023, 2023
Short summary

Franziska Zilker et al.

Franziska Zilker et al.

Viewed

Total article views: 653 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
488 141 24 653 11 10
  • HTML: 488
  • PDF: 141
  • XML: 24
  • Total: 653
  • BibTeX: 11
  • EndNote: 10
Views and downloads (calculated since 30 Mar 2023)
Cumulative views and downloads (calculated since 30 Mar 2023)

Viewed (geographical distribution)

Total article views: 633 (including HTML, PDF, and XML) Thereof 633 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 

Cited

Latest update: 24 Oct 2023
Download

The requested preprint has a corresponding peer-reviewed final revised paper. You are encouraged to refer to the final revised version.

Short summary
The Montreal Protocol (MP) has successfully reduced the Antarctic ozone hole by banning chlorofluorocarbons (CFCs) that destroy the ozone layer. Moreover, CFCs are strong greenhouse gases (GHGs) that would have strengthened global warming. In this study, we investigate the surface weather and climate in a world without the MP at the end of the 21st century disentangling ozone-mediated and GHG impacts of CFCs. Overall, we avoided 1.9 K global surface warming and a poleward shift of storm tracks.