Impact of an AMOC weakening on the stability of the southern Amazon rainforest
The Atlantic Meridional Overturning Circulation (AMOC) and the Amazon rainforest are potential tipping elements of the Earth system, i.e., they may respond with abrupt and potentially irreversible state transitions to a gradual change in forcing once a critical forcing threshold is crossed. With pro...
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ftdatacite:10.17169/refubium-31336 2023-05-15T16:30:23+02:00 Impact of an AMOC weakening on the stability of the southern Amazon rainforest Ciemer, Catrin Winkelmann, Ricarda Kurths, Jürgen Boers, Niklas 2021 https://dx.doi.org/10.17169/refubium-31336 https://refubium.fu-berlin.de/handle/fub188/31604 unknown Freie Universität Berlin https://doi.org/10.1140/epjs/s11734-021-00186-x https://dx.doi.org/10.1140/epjs/s11734-021-00186-x https://doi.org/10.1140/epjs/s11734-021-00186-x Creative Commons Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/legalcode cc-by-4.0 CC-BY Atlantic Meridional Overturning Circulation AMOC Amazon rainforest 500 Naturwissenschaften und Mathematik550 Geowissenschaften, Geologie550 Geowissenschaften Wissenschaftlicher Artikel article-journal Text ScholarlyArticle 2021 ftdatacite https://doi.org/10.17169/refubium-31336 https://doi.org/10.1140/epjs/s11734-021-00186-x 2022-02-08T15:07:01Z The Atlantic Meridional Overturning Circulation (AMOC) and the Amazon rainforest are potential tipping elements of the Earth system, i.e., they may respond with abrupt and potentially irreversible state transitions to a gradual change in forcing once a critical forcing threshold is crossed. With progressing global warming, it becomes more likely that the Amazon will reach such a critical threshold, due to projected reductions of precipitation in tropical South America, which would in turn trigger vegetation transitions from tropical forest to savanna. At the same time, global warming has likely already contributed to a weakening of the AMOC, which induces changes in tropical Atlantic sea-surface temperature (SST) patterns that in turn affect rainfall patterns in the Amazon. A large-scale decline or even dieback of the Amazon rainforest would imply the loss of the largest terrestrial carbon sink, and thereby have drastic consequences for the global climate. Here, we assess the direct impact of greenhouse gas-driven warming of the tropical Atlantic ocean on Amazon rainfall. In addition, we estimate the effect of an AMOC slowdown or collapse, e. g. induced by freshwater flux into the North Atlantic due to melting of the Greenland Ice Sheet, on Amazon rainfall. In order to provide a clear explanation of the underlying dynamics, we use a simple, but robust mathematical approach (based on the classical Stommel two-box model), ensuring consistency with a comprehensive general circulation model (HadGEM3). We find that these two processes, both caused by global warming, are likely to have competing impacts on the rainfall sum in the Amazon, and hence on the stability of the Amazon rainforest. A future AMOC decline may thus counteract direct global-warming-induced rainfall reductions. Tipping of the AMOC from the strong to the weak mode may therefore have a stabilizing effect on the Amazon rainforest. Text Greenland Ice Sheet North Atlantic DataCite Metadata Store (German National Library of Science and Technology) Greenland |
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DataCite Metadata Store (German National Library of Science and Technology) |
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unknown |
topic |
Atlantic Meridional Overturning Circulation AMOC Amazon rainforest 500 Naturwissenschaften und Mathematik550 Geowissenschaften, Geologie550 Geowissenschaften |
spellingShingle |
Atlantic Meridional Overturning Circulation AMOC Amazon rainforest 500 Naturwissenschaften und Mathematik550 Geowissenschaften, Geologie550 Geowissenschaften Ciemer, Catrin Winkelmann, Ricarda Kurths, Jürgen Boers, Niklas Impact of an AMOC weakening on the stability of the southern Amazon rainforest |
topic_facet |
Atlantic Meridional Overturning Circulation AMOC Amazon rainforest 500 Naturwissenschaften und Mathematik550 Geowissenschaften, Geologie550 Geowissenschaften |
description |
The Atlantic Meridional Overturning Circulation (AMOC) and the Amazon rainforest are potential tipping elements of the Earth system, i.e., they may respond with abrupt and potentially irreversible state transitions to a gradual change in forcing once a critical forcing threshold is crossed. With progressing global warming, it becomes more likely that the Amazon will reach such a critical threshold, due to projected reductions of precipitation in tropical South America, which would in turn trigger vegetation transitions from tropical forest to savanna. At the same time, global warming has likely already contributed to a weakening of the AMOC, which induces changes in tropical Atlantic sea-surface temperature (SST) patterns that in turn affect rainfall patterns in the Amazon. A large-scale decline or even dieback of the Amazon rainforest would imply the loss of the largest terrestrial carbon sink, and thereby have drastic consequences for the global climate. Here, we assess the direct impact of greenhouse gas-driven warming of the tropical Atlantic ocean on Amazon rainfall. In addition, we estimate the effect of an AMOC slowdown or collapse, e. g. induced by freshwater flux into the North Atlantic due to melting of the Greenland Ice Sheet, on Amazon rainfall. In order to provide a clear explanation of the underlying dynamics, we use a simple, but robust mathematical approach (based on the classical Stommel two-box model), ensuring consistency with a comprehensive general circulation model (HadGEM3). We find that these two processes, both caused by global warming, are likely to have competing impacts on the rainfall sum in the Amazon, and hence on the stability of the Amazon rainforest. A future AMOC decline may thus counteract direct global-warming-induced rainfall reductions. Tipping of the AMOC from the strong to the weak mode may therefore have a stabilizing effect on the Amazon rainforest. |
format |
Text |
author |
Ciemer, Catrin Winkelmann, Ricarda Kurths, Jürgen Boers, Niklas |
author_facet |
Ciemer, Catrin Winkelmann, Ricarda Kurths, Jürgen Boers, Niklas |
author_sort |
Ciemer, Catrin |
title |
Impact of an AMOC weakening on the stability of the southern Amazon rainforest |
title_short |
Impact of an AMOC weakening on the stability of the southern Amazon rainforest |
title_full |
Impact of an AMOC weakening on the stability of the southern Amazon rainforest |
title_fullStr |
Impact of an AMOC weakening on the stability of the southern Amazon rainforest |
title_full_unstemmed |
Impact of an AMOC weakening on the stability of the southern Amazon rainforest |
title_sort |
impact of an amoc weakening on the stability of the southern amazon rainforest |
publisher |
Freie Universität Berlin |
publishDate |
2021 |
url |
https://dx.doi.org/10.17169/refubium-31336 https://refubium.fu-berlin.de/handle/fub188/31604 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland Ice Sheet North Atlantic |
genre_facet |
Greenland Ice Sheet North Atlantic |
op_relation |
https://doi.org/10.1140/epjs/s11734-021-00186-x https://dx.doi.org/10.1140/epjs/s11734-021-00186-x https://doi.org/10.1140/epjs/s11734-021-00186-x |
op_rights |
Creative Commons Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/legalcode cc-by-4.0 |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.17169/refubium-31336 https://doi.org/10.1140/epjs/s11734-021-00186-x |
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