Weakening of the Atlantic Meridional Overturning Circulation abyssal limb in the North Atlantic
The abyssal limb of the global Meridional Overturning Circulation redistributes heat and carbon as it carries Antarctic Bottom Water from the Southern Ocean towards the Northern Hemisphere. Using mooring observations and hydrographic data from multiple sources in the North Atlantic, we show that nor...
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2024
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Online Access: | https://epic.awi.de/id/eprint/59107/ https://epic.awi.de/id/eprint/59107/1/s41561-024-01422-4.pdf https://doi.org/10.1038/s41561-024-01422-4 https://hdl.handle.net/10013/epic.00e9a9f3-8df5-4381-adc1-035decf7bc2f |
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ftawi:oai:epic.awi.de:59107 2024-09-15T17:40:13+00:00 Weakening of the Atlantic Meridional Overturning Circulation abyssal limb in the North Atlantic Biló, Tiago Carrilho Perez, Renellys C Dong, Shenfu Johns, William Kanzow, Torsten 2024-05 application/pdf https://epic.awi.de/id/eprint/59107/ https://epic.awi.de/id/eprint/59107/1/s41561-024-01422-4.pdf https://doi.org/10.1038/s41561-024-01422-4 https://hdl.handle.net/10013/epic.00e9a9f3-8df5-4381-adc1-035decf7bc2f unknown Springer Nature https://epic.awi.de/id/eprint/59107/1/s41561-024-01422-4.pdf Biló, T. C. , Perez, R. C. , Dong, S. , Johns, W. and Kanzow, T. (2024) Weakening of the Atlantic Meridional Overturning Circulation abyssal limb in the North Atlantic , Nature Geoscience, 17 (5), pp. 419-425 . doi:10.1038/s41561-024-01422-4 <https://doi.org/10.1038/s41561-024-01422-4> , hdl:10013/epic.00e9a9f3-8df5-4381-adc1-035decf7bc2f EPIC3Nature Geoscience, Springer Nature, 17(5), pp. 419-425, ISSN: 1752-0894 Article peerRev 2024 ftawi https://doi.org/10.1038/s41561-024-01422-4 2024-09-02T14:07:29Z The abyssal limb of the global Meridional Overturning Circulation redistributes heat and carbon as it carries Antarctic Bottom Water from the Southern Ocean towards the Northern Hemisphere. Using mooring observations and hydrographic data from multiple sources in the North Atlantic, we show that northward-flowing Antarctic Bottom Water is constrained below 4,500 m with a mean volume transport of 2.40 ± 0.25 Sv at 16° N. We find that during 2000–2020, the Antarctic Bottom Water northward transport weakened by approximately 0.35 ± 0.13 Sv, corresponding to a 12 ± 5% decrease. The weakening of the Atlantic Meridional Overturning Circulation abyssal cell is a probable response to reduced Antarctic Bottom Water formation rates over the past several decades and is associated with abyssal warming observed throughout the western Atlantic Ocean. We estimate that the warming of the Antarctic Bottom Water layer in the subtropical North Atlantic is, on average, 1 m°C per year in the last two decades due to the downward heaving of abyssal isopycnals, contributing to the increase of abyssal heat content and, hence, sea-level rise in the region (1 m°C = 0.001 °C). This warming trend is approximately half of the Antarctic Bottom Water warming trend observed in the South Atlantic and parts of the Southern Ocean, indicating a dilution of the signal as the Antarctic Bottom Water crosses the Equator. Article in Journal/Newspaper Antarc* Antarctic North Atlantic Southern Ocean Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) Nature Geoscience 17 5 419 425 |
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Open Polar |
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Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) |
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ftawi |
language |
unknown |
description |
The abyssal limb of the global Meridional Overturning Circulation redistributes heat and carbon as it carries Antarctic Bottom Water from the Southern Ocean towards the Northern Hemisphere. Using mooring observations and hydrographic data from multiple sources in the North Atlantic, we show that northward-flowing Antarctic Bottom Water is constrained below 4,500 m with a mean volume transport of 2.40 ± 0.25 Sv at 16° N. We find that during 2000–2020, the Antarctic Bottom Water northward transport weakened by approximately 0.35 ± 0.13 Sv, corresponding to a 12 ± 5% decrease. The weakening of the Atlantic Meridional Overturning Circulation abyssal cell is a probable response to reduced Antarctic Bottom Water formation rates over the past several decades and is associated with abyssal warming observed throughout the western Atlantic Ocean. We estimate that the warming of the Antarctic Bottom Water layer in the subtropical North Atlantic is, on average, 1 m°C per year in the last two decades due to the downward heaving of abyssal isopycnals, contributing to the increase of abyssal heat content and, hence, sea-level rise in the region (1 m°C = 0.001 °C). This warming trend is approximately half of the Antarctic Bottom Water warming trend observed in the South Atlantic and parts of the Southern Ocean, indicating a dilution of the signal as the Antarctic Bottom Water crosses the Equator. |
format |
Article in Journal/Newspaper |
author |
Biló, Tiago Carrilho Perez, Renellys C Dong, Shenfu Johns, William Kanzow, Torsten |
spellingShingle |
Biló, Tiago Carrilho Perez, Renellys C Dong, Shenfu Johns, William Kanzow, Torsten Weakening of the Atlantic Meridional Overturning Circulation abyssal limb in the North Atlantic |
author_facet |
Biló, Tiago Carrilho Perez, Renellys C Dong, Shenfu Johns, William Kanzow, Torsten |
author_sort |
Biló, Tiago Carrilho |
title |
Weakening of the Atlantic Meridional Overturning Circulation abyssal limb in the North Atlantic |
title_short |
Weakening of the Atlantic Meridional Overturning Circulation abyssal limb in the North Atlantic |
title_full |
Weakening of the Atlantic Meridional Overturning Circulation abyssal limb in the North Atlantic |
title_fullStr |
Weakening of the Atlantic Meridional Overturning Circulation abyssal limb in the North Atlantic |
title_full_unstemmed |
Weakening of the Atlantic Meridional Overturning Circulation abyssal limb in the North Atlantic |
title_sort |
weakening of the atlantic meridional overturning circulation abyssal limb in the north atlantic |
publisher |
Springer Nature |
publishDate |
2024 |
url |
https://epic.awi.de/id/eprint/59107/ https://epic.awi.de/id/eprint/59107/1/s41561-024-01422-4.pdf https://doi.org/10.1038/s41561-024-01422-4 https://hdl.handle.net/10013/epic.00e9a9f3-8df5-4381-adc1-035decf7bc2f |
genre |
Antarc* Antarctic North Atlantic Southern Ocean |
genre_facet |
Antarc* Antarctic North Atlantic Southern Ocean |
op_source |
EPIC3Nature Geoscience, Springer Nature, 17(5), pp. 419-425, ISSN: 1752-0894 |
op_relation |
https://epic.awi.de/id/eprint/59107/1/s41561-024-01422-4.pdf Biló, T. C. , Perez, R. C. , Dong, S. , Johns, W. and Kanzow, T. (2024) Weakening of the Atlantic Meridional Overturning Circulation abyssal limb in the North Atlantic , Nature Geoscience, 17 (5), pp. 419-425 . doi:10.1038/s41561-024-01422-4 <https://doi.org/10.1038/s41561-024-01422-4> , hdl:10013/epic.00e9a9f3-8df5-4381-adc1-035decf7bc2f |
op_doi |
https://doi.org/10.1038/s41561-024-01422-4 |
container_title |
Nature Geoscience |
container_volume |
17 |
container_issue |
5 |
container_start_page |
419 |
op_container_end_page |
425 |
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1810485682696617984 |