The mechanisms of North Atlantic CO 2 uptake in a large Earth System Model ensemble

The oceans currently take up around a quarter of the carbon dioxide (CO 2 ) emitted by human activity. While stored in the ocean, this CO 2 is not influencing Earth's radiation budget; the ocean CO 2 sink therefore plays an important role in mitigating global warming. CO 2 uptake by the oceans...

Full description

Bibliographic Details
Published in:Biogeosciences
Main Authors: P. R. Halloran, B. B. B. Booth, C. D. Jones, F. H. Lambert, D. J. McNeall, I. J. Totterdell, C. Völker
Format: Article in Journal/Newspaper
Language:English
Published: Copernicus Publications 2015
Subjects:
Online Access:https://doi.org/10.5194/bg-12-4497-2015
https://doaj.org/article/eea3893cfd9d4d218d197af066c13aa1
id ftdoajarticles:oai:doaj.org/article:eea3893cfd9d4d218d197af066c13aa1
record_format openpolar
spelling ftdoajarticles:oai:doaj.org/article:eea3893cfd9d4d218d197af066c13aa1 2023-05-15T17:27:53+02:00 The mechanisms of North Atlantic CO 2 uptake in a large Earth System Model ensemble P. R. Halloran B. B. B. Booth C. D. Jones F. H. Lambert D. J. McNeall I. J. Totterdell C. Völker 2015-07-01T00:00:00Z https://doi.org/10.5194/bg-12-4497-2015 https://doaj.org/article/eea3893cfd9d4d218d197af066c13aa1 EN eng Copernicus Publications http://www.biogeosciences.net/12/4497/2015/bg-12-4497-2015.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 1726-4170 1726-4189 doi:10.5194/bg-12-4497-2015 https://doaj.org/article/eea3893cfd9d4d218d197af066c13aa1 Biogeosciences, Vol 12, Iss 14, Pp 4497-4508 (2015) Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 article 2015 ftdoajarticles https://doi.org/10.5194/bg-12-4497-2015 2022-12-31T01:08:48Z The oceans currently take up around a quarter of the carbon dioxide (CO 2 ) emitted by human activity. While stored in the ocean, this CO 2 is not influencing Earth's radiation budget; the ocean CO 2 sink therefore plays an important role in mitigating global warming. CO 2 uptake by the oceans is heterogeneous, with the subpolar North Atlantic being the strongest CO 2 sink region. Observations over the last 2 decades have indicated that CO 2 uptake by the subpolar North Atlantic sink can vary rapidly. Given the importance of this sink and its apparent variability, it is critical that we understand the mechanisms behind its operation. Here we explore the combined natural and anthropogenic subpolar North Atlantic CO 2 uptake across a large ensemble of Earth System Model simulations, and find that models show a peak in sink strength around the middle of the century after which CO 2 uptake begins to decline. We identify different drivers of change on interannual and multidecadal timescales. Short-term variability appears to be driven by fluctuations in regional seawater temperature and alkalinity, whereas the longer-term evolution throughout the coming century is largely occurring through a counterintuitive response to rising atmospheric CO 2 concentrations. At high atmospheric CO 2 concentrations the contrasting Revelle factors between the low latitude water and the subpolar gyre, combined with the transport of surface waters from the low latitudes to the subpolar gyre, means that the subpolar CO 2 uptake capacity is largely satisfied from its southern boundary rather than through air–sea CO 2 flux. Our findings indicate that: (i) we can explain the mechanisms of subpolar North Atlantic CO 2 uptake variability across a broad range of Earth System Models; (ii) a focus on understanding the mechanisms behind contemporary variability may not directly tell us about how the sink will change in the future; (iii) to identify long-term change in the North Atlantic CO 2 sink we should focus observational resources on ... Article in Journal/Newspaper North Atlantic Directory of Open Access Journals: DOAJ Articles Biogeosciences 12 14 4497 4508
institution Open Polar
collection Directory of Open Access Journals: DOAJ Articles
op_collection_id ftdoajarticles
language English
topic Ecology
QH540-549.5
Life
QH501-531
Geology
QE1-996.5
spellingShingle Ecology
QH540-549.5
Life
QH501-531
Geology
QE1-996.5
P. R. Halloran
B. B. B. Booth
C. D. Jones
F. H. Lambert
D. J. McNeall
I. J. Totterdell
C. Völker
The mechanisms of North Atlantic CO 2 uptake in a large Earth System Model ensemble
topic_facet Ecology
QH540-549.5
Life
QH501-531
Geology
QE1-996.5
description The oceans currently take up around a quarter of the carbon dioxide (CO 2 ) emitted by human activity. While stored in the ocean, this CO 2 is not influencing Earth's radiation budget; the ocean CO 2 sink therefore plays an important role in mitigating global warming. CO 2 uptake by the oceans is heterogeneous, with the subpolar North Atlantic being the strongest CO 2 sink region. Observations over the last 2 decades have indicated that CO 2 uptake by the subpolar North Atlantic sink can vary rapidly. Given the importance of this sink and its apparent variability, it is critical that we understand the mechanisms behind its operation. Here we explore the combined natural and anthropogenic subpolar North Atlantic CO 2 uptake across a large ensemble of Earth System Model simulations, and find that models show a peak in sink strength around the middle of the century after which CO 2 uptake begins to decline. We identify different drivers of change on interannual and multidecadal timescales. Short-term variability appears to be driven by fluctuations in regional seawater temperature and alkalinity, whereas the longer-term evolution throughout the coming century is largely occurring through a counterintuitive response to rising atmospheric CO 2 concentrations. At high atmospheric CO 2 concentrations the contrasting Revelle factors between the low latitude water and the subpolar gyre, combined with the transport of surface waters from the low latitudes to the subpolar gyre, means that the subpolar CO 2 uptake capacity is largely satisfied from its southern boundary rather than through air–sea CO 2 flux. Our findings indicate that: (i) we can explain the mechanisms of subpolar North Atlantic CO 2 uptake variability across a broad range of Earth System Models; (ii) a focus on understanding the mechanisms behind contemporary variability may not directly tell us about how the sink will change in the future; (iii) to identify long-term change in the North Atlantic CO 2 sink we should focus observational resources on ...
format Article in Journal/Newspaper
author P. R. Halloran
B. B. B. Booth
C. D. Jones
F. H. Lambert
D. J. McNeall
I. J. Totterdell
C. Völker
author_facet P. R. Halloran
B. B. B. Booth
C. D. Jones
F. H. Lambert
D. J. McNeall
I. J. Totterdell
C. Völker
author_sort P. R. Halloran
title The mechanisms of North Atlantic CO 2 uptake in a large Earth System Model ensemble
title_short The mechanisms of North Atlantic CO 2 uptake in a large Earth System Model ensemble
title_full The mechanisms of North Atlantic CO 2 uptake in a large Earth System Model ensemble
title_fullStr The mechanisms of North Atlantic CO 2 uptake in a large Earth System Model ensemble
title_full_unstemmed The mechanisms of North Atlantic CO 2 uptake in a large Earth System Model ensemble
title_sort mechanisms of north atlantic co 2 uptake in a large earth system model ensemble
publisher Copernicus Publications
publishDate 2015
url https://doi.org/10.5194/bg-12-4497-2015
https://doaj.org/article/eea3893cfd9d4d218d197af066c13aa1
genre North Atlantic
genre_facet North Atlantic
op_source Biogeosciences, Vol 12, Iss 14, Pp 4497-4508 (2015)
op_relation http://www.biogeosciences.net/12/4497/2015/bg-12-4497-2015.pdf
https://doaj.org/toc/1726-4170
https://doaj.org/toc/1726-4189
1726-4170
1726-4189
doi:10.5194/bg-12-4497-2015
https://doaj.org/article/eea3893cfd9d4d218d197af066c13aa1
op_doi https://doi.org/10.5194/bg-12-4497-2015
container_title Biogeosciences
container_volume 12
container_issue 14
container_start_page 4497
op_container_end_page 4508
_version_ 1766120211950338048