the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
| 02 Dec 2022
The future ozone trends in changing climate simulated with SOCOLv4
Abstract. This study evaluates the future evolution of atmospheric ozone between 2015 and 2099 simulated with the Earth System Model (ESM) SOCOLv4. Simulations have been performed based on two potential Shared Socioeconomic Pathways (SSP): the “middle-of-the-road” (SSP2-4.5) and “fossil-fueled” (SSP5-8.5) scenarios. In both scenarios, the model projects a decline in tropospheric ozone in the future that starts in the 2030s in SSP2-4.5 and after the 2060s in SSP5-8.5 due to a decrease in concentrations of ozone precursors like NOx and CO. The results also suggest a very likely ozone increase in the mesosphere, upper and middle stratosphere, as well as at high latitudes of the lower stratosphere. Under SSP5-8.5, the ozone increase in the stratosphere is higher because of stronger cooling (> 1 °K/decade) induced by the greenhouse gases (GHG), which slows the catalytic ozone destruction cycles. In contrast, in the tropical lower stratosphere ozone concentrations decrease in both experiments and increase over the middle and high latitudes of both hemispheres due to the intensification of meridional transport, which is stronger in SSP5-8.5. No evidence was found of a decline in ozone levels in the lower stratosphere at mid-latitudes. In both future scenarios, the total column ozone is expected to be distinctly higher than present in mid-to-high latitudes and might be lower in the tropics, which causes a decrease/increase in the surface level of UV radiation. The results of SOCOLv4 suggest that the stratospheric ozone evolution throughout the 21st century is strongly governed not only by a decline in halogen concentration, but also by future GHGs forcing. In addition, the tropospheric ozone column changes, mainly due to the changes in anthropogenic emissions of ozone precursors, also have a strong impact on the total column. Therefore, even though the anthropogenic halogen loading problem has been brought under control to date, the sign of future ozone column changes, globally and regionally, is still unclear and largely depends on diverse future human activities. The results of this work are, thus, relevant for developing future strategies for socioeconomic pathways.
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Notice on discussion status
The requested preprint has a corresponding peer-reviewed final revised paper. You are encouraged to refer to the final revised version.
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Preprint
(2876 KB)
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The requested preprint has a corresponding peer-reviewed final revised paper. You are encouraged to refer to the final revised version.
- Preprint
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- Final revised paper
Journal article(s) based on this preprint
Interactive discussion
Status: closed
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RC1: 'Comment on egusphere-2022-1260', Anonymous Referee #1, 04 Jan 2023
Review for Karagodin-Doyennel et al., “The future ozone trends in changing climate simulated with SOCOLv4”, submitted to ACP
Here authors use the SOCOLv4 Earth System Model (ESM) to simulate future ozone evolution. Results from two model simulations (based on two potential Shared Socioeconomic Pathways (SSP) scenarios: SSP2-4.5 and SSP5-8.5) are presented. SOCOL_v4 predicts a decline in tropospheric ozone around the 2030s for SSP2-4.5 and after 2060s under SSP5-8.5 scenarios primarily due to decrease in ozone precursors such as NOx and CO. As expected, models also predict ozone increase in the upper/ middle stratosphere globally and high-latitude lower stratosphere. Model also predicts that under SSP5-8.5, the stratospheric ozone increases are largely due to stronger stratospheric cooling as more greenhouse gases lead to more cooling that slows ozone loss. On the other hand, both the simulations predict ozone decrease in the tropical lower stratosphere as strengthening of BD circulation transports more ozone to the mid-high latitudes.
As confirmed by various recent studies, the model does not predict any decrease in lower stratospheric ozone at mid-latitudes. Consistent with our understanding, SOCOLv4 predicts an increase in stratospheric ozone in the 21st century due to decreases in the ODS and increases in the GHGs.
Overall, this is a well organised manuscript with some room for improvements. So I would recommend the manuscript for the publications if authors can address minor comments suggested below
- I am struggling to find clear motivation. What are the largest sources of uncertainties in our understanding about the future evolution of ozone layer . What was done in earlier SOCOL studies and what was missing and how this manuscript is able to improve those biases. There are serveral papers like Morganstern et al., Dhomse et al., Keeble et al, highlighting the role of GHG in explaining decreases in tropical ozone. So, what is new here?
- Why there is a paragraph about the VSLS if there are no plots showing its impact on the ozone layer?
- Can you explain why sAOD term is included in DLM model though there is no volcanic eruption in the simulations
- Line 198: Usage of DLM to model simulated data is still unclear. Please include some clear information explaining why this type of analysis should use DLM rather than multivariate (or ordinary least square) regression or simpler composite analysis. I strongly feel that using DLM for the analysis of observational data is OK as we have just one realisation about the past atmosphere. But as you have 3 ensemble members for each type of simulation, does DLM provide unique insight in model world compared to simple averaging and smoothing?
Technical
Line 115: Hu et al. (2015),
Line 163: Only GHGs (prescribed ODSs are identical)?
Citation: https://doi.org/10.5194/egusphere-2022-1260-RC1 - AC1: 'Reply on RC1', Arseniy Karagodin-Doyennel, 13 Mar 2023
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RC2: 'Comment on egusphere-2022-1260', Anonymous Referee #2, 23 Jan 2023
The MS: “The future ozone trends in changing climate simulated with SOCOLv4” deals with ozone evolution in the “middle-of-the-road” (SSP2-4.5) and “fossil-fueled” (SSP5-8.5) scenarios in the troposphere and middle atmosphere. As the authors have already presented the results from their historical simulations and comparisons to measurements in another paper, this study concentrates only on the future changes.
As expected, ozone is in increasing in the stratosphere and decreasing in the lower stratosphere and troposphere. However, the mesospheric part is interesting as there are not many analyses for this region. This is a well-written MS and I have only some minor comments on this.
Major:
I thought a comparison between the previous RCP scenarios with the latest SSP scenarios is needed in the discussion. There are some studies based on CIMIP 5 ozone results. This should be in the modelling point of view. You have mentioned some in Introduction, but a discussion of the ozone results from both CMIP5 and CIMP6 are needed.
Minor:
L6: “and upper and middle”
L9: speed up of BDC?
L11-12: increase of UV in the tropics or mid latitudes?
L20: element? You need a better word here
L31: The following studies should also be mentioned here
https://doi.org/10.5194/acp-18-7557-2018
https://doi.org/10.1038/s41612-018-0052-6
L38: GHG was first mentioned in L23
L84: space after full stop
L89: decrease (Keeble et al., 2021).
L102: what is “slightly“ comparable;?
L115: Hue et al. (2016)
L119: CCMI campaigns? Sounds a filed campaign, not modelling experiments
L168: respectively (Zhao et al., 2020)
L192: indices
L241, 245: delete content, use amount or concentration instead
L248: signs of increase
L251-252: how NOx produces ozone in the lower stratosphere?
L253: do not start a sent with AND
L260: These increases of 0.13 and 0.27 DU are significant?
L269: Can you please give another reference for this. It is known long before, not in 2021
L299: as expected
L369: delete the “expected”
L382: it barely changes? Then you write a change of -4DU/decade? Delete “barely”
Citation: https://doi.org/10.5194/egusphere-2022-1260-RC2 - AC2: 'Reply on RC2', Arseniy Karagodin-Doyennel, 13 Mar 2023
Interactive discussion
Status: closed
-
RC1: 'Comment on egusphere-2022-1260', Anonymous Referee #1, 04 Jan 2023
Review for Karagodin-Doyennel et al., “The future ozone trends in changing climate simulated with SOCOLv4”, submitted to ACP
Here authors use the SOCOLv4 Earth System Model (ESM) to simulate future ozone evolution. Results from two model simulations (based on two potential Shared Socioeconomic Pathways (SSP) scenarios: SSP2-4.5 and SSP5-8.5) are presented. SOCOL_v4 predicts a decline in tropospheric ozone around the 2030s for SSP2-4.5 and after 2060s under SSP5-8.5 scenarios primarily due to decrease in ozone precursors such as NOx and CO. As expected, models also predict ozone increase in the upper/ middle stratosphere globally and high-latitude lower stratosphere. Model also predicts that under SSP5-8.5, the stratospheric ozone increases are largely due to stronger stratospheric cooling as more greenhouse gases lead to more cooling that slows ozone loss. On the other hand, both the simulations predict ozone decrease in the tropical lower stratosphere as strengthening of BD circulation transports more ozone to the mid-high latitudes.
As confirmed by various recent studies, the model does not predict any decrease in lower stratospheric ozone at mid-latitudes. Consistent with our understanding, SOCOLv4 predicts an increase in stratospheric ozone in the 21st century due to decreases in the ODS and increases in the GHGs.
Overall, this is a well organised manuscript with some room for improvements. So I would recommend the manuscript for the publications if authors can address minor comments suggested below
- I am struggling to find clear motivation. What are the largest sources of uncertainties in our understanding about the future evolution of ozone layer . What was done in earlier SOCOL studies and what was missing and how this manuscript is able to improve those biases. There are serveral papers like Morganstern et al., Dhomse et al., Keeble et al, highlighting the role of GHG in explaining decreases in tropical ozone. So, what is new here?
- Why there is a paragraph about the VSLS if there are no plots showing its impact on the ozone layer?
- Can you explain why sAOD term is included in DLM model though there is no volcanic eruption in the simulations
- Line 198: Usage of DLM to model simulated data is still unclear. Please include some clear information explaining why this type of analysis should use DLM rather than multivariate (or ordinary least square) regression or simpler composite analysis. I strongly feel that using DLM for the analysis of observational data is OK as we have just one realisation about the past atmosphere. But as you have 3 ensemble members for each type of simulation, does DLM provide unique insight in model world compared to simple averaging and smoothing?
Technical
Line 115: Hu et al. (2015),
Line 163: Only GHGs (prescribed ODSs are identical)?
Citation: https://doi.org/10.5194/egusphere-2022-1260-RC1 - AC1: 'Reply on RC1', Arseniy Karagodin-Doyennel, 13 Mar 2023
-
RC2: 'Comment on egusphere-2022-1260', Anonymous Referee #2, 23 Jan 2023
The MS: “The future ozone trends in changing climate simulated with SOCOLv4” deals with ozone evolution in the “middle-of-the-road” (SSP2-4.5) and “fossil-fueled” (SSP5-8.5) scenarios in the troposphere and middle atmosphere. As the authors have already presented the results from their historical simulations and comparisons to measurements in another paper, this study concentrates only on the future changes.
As expected, ozone is in increasing in the stratosphere and decreasing in the lower stratosphere and troposphere. However, the mesospheric part is interesting as there are not many analyses for this region. This is a well-written MS and I have only some minor comments on this.
Major:
I thought a comparison between the previous RCP scenarios with the latest SSP scenarios is needed in the discussion. There are some studies based on CIMIP 5 ozone results. This should be in the modelling point of view. You have mentioned some in Introduction, but a discussion of the ozone results from both CMIP5 and CIMP6 are needed.
Minor:
L6: “and upper and middle”
L9: speed up of BDC?
L11-12: increase of UV in the tropics or mid latitudes?
L20: element? You need a better word here
L31: The following studies should also be mentioned here
https://doi.org/10.5194/acp-18-7557-2018
https://doi.org/10.1038/s41612-018-0052-6
L38: GHG was first mentioned in L23
L84: space after full stop
L89: decrease (Keeble et al., 2021).
L102: what is “slightly“ comparable;?
L115: Hue et al. (2016)
L119: CCMI campaigns? Sounds a filed campaign, not modelling experiments
L168: respectively (Zhao et al., 2020)
L192: indices
L241, 245: delete content, use amount or concentration instead
L248: signs of increase
L251-252: how NOx produces ozone in the lower stratosphere?
L253: do not start a sent with AND
L260: These increases of 0.13 and 0.27 DU are significant?
L269: Can you please give another reference for this. It is known long before, not in 2021
L299: as expected
L369: delete the “expected”
L382: it barely changes? Then you write a change of -4DU/decade? Delete “barely”
Citation: https://doi.org/10.5194/egusphere-2022-1260-RC2 - AC2: 'Reply on RC2', Arseniy Karagodin-Doyennel, 13 Mar 2023
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Cited
Arseniy Karagodin-Doyennel
Eugene Rozanov
Timofei Sukhodolov
Tatiana Egorova
Jan Sedlacek
Thomas Peter
The requested preprint has a corresponding peer-reviewed final revised paper. You are encouraged to refer to the final revised version.
- Preprint
(2876 KB) - Metadata XML