Stratospheric ozone response to sulfate aerosol and solar dimming climate interventions based on the G6 Geoengineering Model Intercomparison Project (GeoMIP) simulations

• Published in: Atmospheric Chemistry and Physics
• Main Authors: Tilmes, Simone, Visioni, Daniele, Jones, Andy, Haywood, James, Séférian, Roland, Nabat, Pierre, Boucher, Olivier, Monica Bednarz, Ewa, Niemeier, Ulrike
• Other Authors: National Center for Atmospheric Research Boulder (NCAR), Cornell University New York, Met Office Hadley Centre (MOHC), United Kingdom Met Office Exeter, Centre national de recherches météorologiques (CNRM), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Centre National de la Recherche Scientifique (CNRS), Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X), Institut Polytechnique de Paris (IP Paris)-Institut Polytechnique de Paris (IP Paris)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Sorbonne Université (SU), Max Planck Institute for Meteorology (MPI-M), Max-Planck-Gesellschaft, ANR-17-EURE-0006,IPSL-CGS,IPSL Climate graduate school(2017), ANR-11-IDEX-0004,SUPER,Sorbonne Universités à Paris pour l'Enseignement et la Recherche(2011)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2022
• Subjects: [SDE]Environmental Sciences; Antarctic; Antarc*
• Online Access: https://hal.science/hal-03640125; https://hal.science/hal-03640125v1/document; https://hal.science/hal-03640125v1/file/acp-22-4557-2022.pdf; https://doi.org/10.5194/acp-22-4557-2022

International audience This study assesses the impacts of stratospheric aerosol intervention (SAI) and solar dimming on stratospheric ozone based on the G6 Geoengineering Model Intercomparison Project (GeoMIP) experiments, called G6sulfur and G6solar. For G6sulfur, an enhanced stratospheric sulfate aerosol burden reflects some of the incoming solar radiation back into space to cool the surface climate, while for G6solar, the reduction in the global solar constant in the model achieves the same goal. Both experiments use the high emissions scenario of SSP5-8.5 as the baseline experiment and define surface temperature from the medium emission scenario of SSP2-4.5 as the target. In total, six Earth system models (ESMs) performed these experiments, and three out of the six models include interactive stratospheric chemistry. The increase in absorbing sulfate aerosols in the stratosphere results in a heating of the lower tropical stratospheric temperatures by between 5 to 13 K for the six different ESMs, leading to changes in stratospheric transport, water vapor, and other related changes. The increase in the aerosol burden also increases aerosol surface area density, which is important for heterogeneous chemical reactions. The resulting changes in the springtime Antarctic ozone between the G6sulfur and SSP5-8.5, based on the three models with interactive chemistry, include an initial reduction in total column ozone (TCO) of 10 DU (ranging between 0-30 DU for the three models) and up to 20 DU (between 10-40 DU) by the end of the century. The relatively small reduction in TCO for the multi-model mean in the first 2 decades results from variations in the required sulfur injections in the models and differences in the complexity of the chemistry schemes. In contrast, in the Northern Hemisphere (NH) high latitudes, no significant changes can be identified due to the large natural variability in the models, with little change in TCO by the end of the century. However, all three models with interactive chemistry ...