Pantropical Indo-Atlantic temperature gradient modulates multi-decadal AMOC variability in models and observations
Abstract Interconnections between ocean basins are recognized as an important driver of climate variability. Recent modeling evidence suggests that the North Atlantic climate can respond to persistent warming of the tropical Indian Ocean sea surface temperature (SST) relative to the rest of the trop...
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ftdoajarticles:oai:doaj.org/article:8549e717339a4d8195de6b8bfba9853b 2023-11-12T04:21:52+01:00 Pantropical Indo-Atlantic temperature gradient modulates multi-decadal AMOC variability in models and observations Brady S. Ferster Leonard F. Borchert Juliette Mignot Matthew B. Menary Christophe Cassou Alexey V. Fedorov 2023-10-01T00:00:00Z https://doi.org/10.1038/s41612-023-00489-x https://doaj.org/article/8549e717339a4d8195de6b8bfba9853b EN eng Nature Portfolio https://doi.org/10.1038/s41612-023-00489-x https://doaj.org/toc/2397-3722 doi:10.1038/s41612-023-00489-x 2397-3722 https://doaj.org/article/8549e717339a4d8195de6b8bfba9853b npj Climate and Atmospheric Science, Vol 6, Iss 1, Pp 1-8 (2023) Environmental sciences GE1-350 Meteorology. Climatology QC851-999 article 2023 ftdoajarticles https://doi.org/10.1038/s41612-023-00489-x 2023-10-29T00:42:08Z Abstract Interconnections between ocean basins are recognized as an important driver of climate variability. Recent modeling evidence suggests that the North Atlantic climate can respond to persistent warming of the tropical Indian Ocean sea surface temperature (SST) relative to the rest of the tropics (rTIO). Here, we use observational data to demonstrate that multi-decadal changes in pantropical ocean temperature gradients lead to variations of an SST-based proxy of the Atlantic Meridional Overturning Circulation (AMOC). The largest contribution to this temperature gradient-AMOC connection comes from gradients between the Indian and Atlantic Oceans. The rTIO index yields the strongest connection of this tropical temperature gradient to the AMOC. Focusing on the internally generated signal in three observational products reveals that an SST-based AMOC proxy index has closely followed low-frequency changes of rTIO temperature with about 26-year lag since 1870. Analyzing the pre-industrial control simulations of 44 CMIP6 climate models shows that the AMOC proxy index lags simulated mid-latitude AMOC variations by 4 ± 4 years. These model simulations reveal the mechanism connecting AMOC variations to pantropical ocean temperature gradients at a 27 ± 2 years lag, matching the observed time lag in 28 out of the 44 analyzed models. rTIO temperature changes affect the North Atlantic climate through atmospheric planetary waves, impacting temperature and salinity in the subpolar North Atlantic, which modifies deep convection and ultimately the AMOC. Through this mechanism, observed internal rTIO variations can serve as a multi-decadal precursor of AMOC changes with important implications for AMOC dynamics and predictability. Article in Journal/Newspaper North Atlantic Directory of Open Access Journals: DOAJ Articles npj Climate and Atmospheric Science 6 1 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Environmental sciences GE1-350 Meteorology. Climatology QC851-999 |
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Environmental sciences GE1-350 Meteorology. Climatology QC851-999 Brady S. Ferster Leonard F. Borchert Juliette Mignot Matthew B. Menary Christophe Cassou Alexey V. Fedorov Pantropical Indo-Atlantic temperature gradient modulates multi-decadal AMOC variability in models and observations |
topic_facet |
Environmental sciences GE1-350 Meteorology. Climatology QC851-999 |
description |
Abstract Interconnections between ocean basins are recognized as an important driver of climate variability. Recent modeling evidence suggests that the North Atlantic climate can respond to persistent warming of the tropical Indian Ocean sea surface temperature (SST) relative to the rest of the tropics (rTIO). Here, we use observational data to demonstrate that multi-decadal changes in pantropical ocean temperature gradients lead to variations of an SST-based proxy of the Atlantic Meridional Overturning Circulation (AMOC). The largest contribution to this temperature gradient-AMOC connection comes from gradients between the Indian and Atlantic Oceans. The rTIO index yields the strongest connection of this tropical temperature gradient to the AMOC. Focusing on the internally generated signal in three observational products reveals that an SST-based AMOC proxy index has closely followed low-frequency changes of rTIO temperature with about 26-year lag since 1870. Analyzing the pre-industrial control simulations of 44 CMIP6 climate models shows that the AMOC proxy index lags simulated mid-latitude AMOC variations by 4 ± 4 years. These model simulations reveal the mechanism connecting AMOC variations to pantropical ocean temperature gradients at a 27 ± 2 years lag, matching the observed time lag in 28 out of the 44 analyzed models. rTIO temperature changes affect the North Atlantic climate through atmospheric planetary waves, impacting temperature and salinity in the subpolar North Atlantic, which modifies deep convection and ultimately the AMOC. Through this mechanism, observed internal rTIO variations can serve as a multi-decadal precursor of AMOC changes with important implications for AMOC dynamics and predictability. |
format |
Article in Journal/Newspaper |
author |
Brady S. Ferster Leonard F. Borchert Juliette Mignot Matthew B. Menary Christophe Cassou Alexey V. Fedorov |
author_facet |
Brady S. Ferster Leonard F. Borchert Juliette Mignot Matthew B. Menary Christophe Cassou Alexey V. Fedorov |
author_sort |
Brady S. Ferster |
title |
Pantropical Indo-Atlantic temperature gradient modulates multi-decadal AMOC variability in models and observations |
title_short |
Pantropical Indo-Atlantic temperature gradient modulates multi-decadal AMOC variability in models and observations |
title_full |
Pantropical Indo-Atlantic temperature gradient modulates multi-decadal AMOC variability in models and observations |
title_fullStr |
Pantropical Indo-Atlantic temperature gradient modulates multi-decadal AMOC variability in models and observations |
title_full_unstemmed |
Pantropical Indo-Atlantic temperature gradient modulates multi-decadal AMOC variability in models and observations |
title_sort |
pantropical indo-atlantic temperature gradient modulates multi-decadal amoc variability in models and observations |
publisher |
Nature Portfolio |
publishDate |
2023 |
url |
https://doi.org/10.1038/s41612-023-00489-x https://doaj.org/article/8549e717339a4d8195de6b8bfba9853b |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
npj Climate and Atmospheric Science, Vol 6, Iss 1, Pp 1-8 (2023) |
op_relation |
https://doi.org/10.1038/s41612-023-00489-x https://doaj.org/toc/2397-3722 doi:10.1038/s41612-023-00489-x 2397-3722 https://doaj.org/article/8549e717339a4d8195de6b8bfba9853b |
op_doi |
https://doi.org/10.1038/s41612-023-00489-x |
container_title |
npj Climate and Atmospheric Science |
container_volume |
6 |
container_issue |
1 |
_version_ |
1782337099250270208 |