Impacts of three types of solar geoengineering on the Atlantic Meridional Overturning Circulation
Climate models simulate lower rates of North Atlantic heat transport under greenhouse gas climates than at present due to a reduction in the strength of the Atlantic Meridional Overturning Circulation (AMOC). Solar geoengineering whereby surface temperatures are cooled by reduction of incoming short...
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ftcopernicus:oai:publications.copernicus.org:acp98604 2023-05-15T15:06:41+02:00 Impacts of three types of solar geoengineering on the Atlantic Meridional Overturning Circulation Xie, Mengdie Moore, John C. Zhao, Liyun Wolovick, Michael Muri, Helene 2022-04-08 application/pdf https://doi.org/10.5194/acp-22-4581-2022 https://acp.copernicus.org/articles/22/4581/2022/ eng eng doi:10.5194/acp-22-4581-2022 https://acp.copernicus.org/articles/22/4581/2022/ eISSN: 1680-7324 Text 2022 ftcopernicus https://doi.org/10.5194/acp-22-4581-2022 2022-04-11T16:22:17Z Climate models simulate lower rates of North Atlantic heat transport under greenhouse gas climates than at present due to a reduction in the strength of the Atlantic Meridional Overturning Circulation (AMOC). Solar geoengineering whereby surface temperatures are cooled by reduction of incoming shortwave radiation may be expected to ameliorate this effect. We investigate this using six Earth system models running scenarios from GeoMIP (Geoengineering Model Intercomparison Project) in the cases of (i) reduction in the solar constant, mimicking dimming of the sun; (ii) sulfate aerosol injection into the lower equatorial stratosphere; and (iii) brightening of the ocean regions, mimicking enhancing tropospheric cloud amounts. We find that despite across-model differences, AMOC decreases are attributable to reduced air–ocean temperature differences and reduced September Arctic sea ice extent, with no significant impact from changing surface winds or precipitation − evaporation. Reversing the surface freshening of the North Atlantic overturning regions caused by decreased summer sea ice sea helps to promote AMOC. When comparing the geoengineering types after normalizing them for the differences in top-of-atmosphere radiative forcing, we find that solar dimming is more effective than either marine cloud brightening or stratospheric aerosol injection. Text Arctic North Atlantic Sea ice Copernicus Publications: E-Journals Arctic Atmospheric Chemistry and Physics 22 7 4581 4597 |
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Copernicus Publications: E-Journals |
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English |
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Climate models simulate lower rates of North Atlantic heat transport under greenhouse gas climates than at present due to a reduction in the strength of the Atlantic Meridional Overturning Circulation (AMOC). Solar geoengineering whereby surface temperatures are cooled by reduction of incoming shortwave radiation may be expected to ameliorate this effect. We investigate this using six Earth system models running scenarios from GeoMIP (Geoengineering Model Intercomparison Project) in the cases of (i) reduction in the solar constant, mimicking dimming of the sun; (ii) sulfate aerosol injection into the lower equatorial stratosphere; and (iii) brightening of the ocean regions, mimicking enhancing tropospheric cloud amounts. We find that despite across-model differences, AMOC decreases are attributable to reduced air–ocean temperature differences and reduced September Arctic sea ice extent, with no significant impact from changing surface winds or precipitation − evaporation. Reversing the surface freshening of the North Atlantic overturning regions caused by decreased summer sea ice sea helps to promote AMOC. When comparing the geoengineering types after normalizing them for the differences in top-of-atmosphere radiative forcing, we find that solar dimming is more effective than either marine cloud brightening or stratospheric aerosol injection. |
format |
Text |
author |
Xie, Mengdie Moore, John C. Zhao, Liyun Wolovick, Michael Muri, Helene |
spellingShingle |
Xie, Mengdie Moore, John C. Zhao, Liyun Wolovick, Michael Muri, Helene Impacts of three types of solar geoengineering on the Atlantic Meridional Overturning Circulation |
author_facet |
Xie, Mengdie Moore, John C. Zhao, Liyun Wolovick, Michael Muri, Helene |
author_sort |
Xie, Mengdie |
title |
Impacts of three types of solar geoengineering on the Atlantic Meridional Overturning Circulation |
title_short |
Impacts of three types of solar geoengineering on the Atlantic Meridional Overturning Circulation |
title_full |
Impacts of three types of solar geoengineering on the Atlantic Meridional Overturning Circulation |
title_fullStr |
Impacts of three types of solar geoengineering on the Atlantic Meridional Overturning Circulation |
title_full_unstemmed |
Impacts of three types of solar geoengineering on the Atlantic Meridional Overturning Circulation |
title_sort |
impacts of three types of solar geoengineering on the atlantic meridional overturning circulation |
publishDate |
2022 |
url |
https://doi.org/10.5194/acp-22-4581-2022 https://acp.copernicus.org/articles/22/4581/2022/ |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic North Atlantic Sea ice |
genre_facet |
Arctic North Atlantic Sea ice |
op_source |
eISSN: 1680-7324 |
op_relation |
doi:10.5194/acp-22-4581-2022 https://acp.copernicus.org/articles/22/4581/2022/ |
op_doi |
https://doi.org/10.5194/acp-22-4581-2022 |
container_title |
Atmospheric Chemistry and Physics |
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22 |
container_issue |
7 |
container_start_page |
4581 |
op_container_end_page |
4597 |
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1766338246975946752 |