Impacts of three types of solar geoengineering on the North 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 North Atlantic meridional overturning circulation (AMOC). Solar geoengineering whereby surface temperatures are cooled by reduction of incoming...
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ftcopernicus:oai:publications.copernicus.org:acpd98604 2023-05-15T15:06:41+02:00 Impacts of three types of solar geoengineering on the North Atlantic Meridional Overturning Circulation Xie, Mengdie Moore, John C. Zhao, Liyun Wolovick, Michael Muri, Helene 2021-11-12 application/pdf https://doi.org/10.5194/acp-2021-877 https://acp.copernicus.org/preprints/acp-2021-877/ eng eng doi:10.5194/acp-2021-877 https://acp.copernicus.org/preprints/acp-2021-877/ eISSN: 1680-7324 Text 2021 ftcopernicus https://doi.org/10.5194/acp-2021-877 2021-11-15T17:22:28Z 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 North 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. 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 |
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Copernicus Publications: E-Journals |
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ftcopernicus |
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English |
description |
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 North 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. 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 North 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 North Atlantic Meridional Overturning Circulation |
title_short |
Impacts of three types of solar geoengineering on the North Atlantic Meridional Overturning Circulation |
title_full |
Impacts of three types of solar geoengineering on the North Atlantic Meridional Overturning Circulation |
title_fullStr |
Impacts of three types of solar geoengineering on the North Atlantic Meridional Overturning Circulation |
title_full_unstemmed |
Impacts of three types of solar geoengineering on the North Atlantic Meridional Overturning Circulation |
title_sort |
impacts of three types of solar geoengineering on the north atlantic meridional overturning circulation |
publishDate |
2021 |
url |
https://doi.org/10.5194/acp-2021-877 https://acp.copernicus.org/preprints/acp-2021-877/ |
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-2021-877 https://acp.copernicus.org/preprints/acp-2021-877/ |
op_doi |
https://doi.org/10.5194/acp-2021-877 |
_version_ |
1766338246126600192 |