Observation-constrained estimates of the global ocean carbon sink from Earth system models
The ocean slows global warming by currently taking up around one-quarter of all human-made CO 2 emissions. However, estimates of the ocean anthropogenic carbon uptake vary across various observation-based and model-based approaches. Here, we show that the global ocean anthropogenic carbon sink simul...
Published in: | Biogeosciences |
---|---|
Main Authors: | , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Copernicus Publications
2022
|
Subjects: | |
Online Access: | https://doi.org/10.5194/bg-19-4431-2022 https://doaj.org/article/0ba0c320af094ef6a8221055b894ca93 |
id |
ftdoajarticles:oai:doaj.org/article:0ba0c320af094ef6a8221055b894ca93 |
---|---|
record_format |
openpolar |
spelling |
ftdoajarticles:oai:doaj.org/article:0ba0c320af094ef6a8221055b894ca93 2023-05-15T17:52:03+02:00 Observation-constrained estimates of the global ocean carbon sink from Earth system models J. Terhaar T. L. Frölicher F. Joos 2022-09-01T00:00:00Z https://doi.org/10.5194/bg-19-4431-2022 https://doaj.org/article/0ba0c320af094ef6a8221055b894ca93 EN eng Copernicus Publications https://bg.copernicus.org/articles/19/4431/2022/bg-19-4431-2022.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 doi:10.5194/bg-19-4431-2022 1726-4170 1726-4189 https://doaj.org/article/0ba0c320af094ef6a8221055b894ca93 Biogeosciences, Vol 19, Pp 4431-4457 (2022) Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 article 2022 ftdoajarticles https://doi.org/10.5194/bg-19-4431-2022 2022-12-30T19:51:14Z The ocean slows global warming by currently taking up around one-quarter of all human-made CO 2 emissions. However, estimates of the ocean anthropogenic carbon uptake vary across various observation-based and model-based approaches. Here, we show that the global ocean anthropogenic carbon sink simulated by Earth system models can be constrained by two physical parameters, the present-day sea surface salinity in the subtropical–polar frontal zone in the Southern Ocean and the strength of the Atlantic Meridional Overturning Circulation, and one biogeochemical parameter, the Revelle factor of the global surface ocean. The Revelle factor quantifies the chemical capacity of seawater to take up carbon for a given increase in atmospheric CO 2 . By exploiting this three-dimensional emergent constraint with observations, we provide a new model- and observation-based estimate of the past, present, and future global ocean anthropogenic carbon sink and show that the ocean carbon sink is 9 %–11 % larger than previously estimated. Furthermore, the constraint reduces uncertainties of the past and present global ocean anthropogenic carbon sink by 42 %–59 % and the future sink by 32 %–62 % depending on the scenario, allowing for a better understanding of the global carbon cycle and better-targeted climate and ocean policies. Our constrained results are in good agreement with the anthropogenic carbon air–sea flux estimates over the last three decades based on observations of the CO 2 partial pressure at the ocean surface in the Global Carbon Budget 2021, and they suggest that existing hindcast ocean-only model simulations underestimate the global ocean anthropogenic carbon sink. The key parameters identified here for the ocean anthropogenic carbon sink should be quantified when presenting simulated ocean anthropogenic carbon uptake as in the Global Carbon Budget and be used to adjust these simulated estimates if necessary. The larger ocean carbon sink results in enhanced ocean acidification over the 21st century, which further ... Article in Journal/Newspaper Ocean acidification Southern Ocean Directory of Open Access Journals: DOAJ Articles Southern Ocean Biogeosciences 19 18 4431 4457 |
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 J. Terhaar T. L. Frölicher F. Joos Observation-constrained estimates of the global ocean carbon sink from Earth system models |
topic_facet |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 |
description |
The ocean slows global warming by currently taking up around one-quarter of all human-made CO 2 emissions. However, estimates of the ocean anthropogenic carbon uptake vary across various observation-based and model-based approaches. Here, we show that the global ocean anthropogenic carbon sink simulated by Earth system models can be constrained by two physical parameters, the present-day sea surface salinity in the subtropical–polar frontal zone in the Southern Ocean and the strength of the Atlantic Meridional Overturning Circulation, and one biogeochemical parameter, the Revelle factor of the global surface ocean. The Revelle factor quantifies the chemical capacity of seawater to take up carbon for a given increase in atmospheric CO 2 . By exploiting this three-dimensional emergent constraint with observations, we provide a new model- and observation-based estimate of the past, present, and future global ocean anthropogenic carbon sink and show that the ocean carbon sink is 9 %–11 % larger than previously estimated. Furthermore, the constraint reduces uncertainties of the past and present global ocean anthropogenic carbon sink by 42 %–59 % and the future sink by 32 %–62 % depending on the scenario, allowing for a better understanding of the global carbon cycle and better-targeted climate and ocean policies. Our constrained results are in good agreement with the anthropogenic carbon air–sea flux estimates over the last three decades based on observations of the CO 2 partial pressure at the ocean surface in the Global Carbon Budget 2021, and they suggest that existing hindcast ocean-only model simulations underestimate the global ocean anthropogenic carbon sink. The key parameters identified here for the ocean anthropogenic carbon sink should be quantified when presenting simulated ocean anthropogenic carbon uptake as in the Global Carbon Budget and be used to adjust these simulated estimates if necessary. The larger ocean carbon sink results in enhanced ocean acidification over the 21st century, which further ... |
format |
Article in Journal/Newspaper |
author |
J. Terhaar T. L. Frölicher F. Joos |
author_facet |
J. Terhaar T. L. Frölicher F. Joos |
author_sort |
J. Terhaar |
title |
Observation-constrained estimates of the global ocean carbon sink from Earth system models |
title_short |
Observation-constrained estimates of the global ocean carbon sink from Earth system models |
title_full |
Observation-constrained estimates of the global ocean carbon sink from Earth system models |
title_fullStr |
Observation-constrained estimates of the global ocean carbon sink from Earth system models |
title_full_unstemmed |
Observation-constrained estimates of the global ocean carbon sink from Earth system models |
title_sort |
observation-constrained estimates of the global ocean carbon sink from earth system models |
publisher |
Copernicus Publications |
publishDate |
2022 |
url |
https://doi.org/10.5194/bg-19-4431-2022 https://doaj.org/article/0ba0c320af094ef6a8221055b894ca93 |
geographic |
Southern Ocean |
geographic_facet |
Southern Ocean |
genre |
Ocean acidification Southern Ocean |
genre_facet |
Ocean acidification Southern Ocean |
op_source |
Biogeosciences, Vol 19, Pp 4431-4457 (2022) |
op_relation |
https://bg.copernicus.org/articles/19/4431/2022/bg-19-4431-2022.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 doi:10.5194/bg-19-4431-2022 1726-4170 1726-4189 https://doaj.org/article/0ba0c320af094ef6a8221055b894ca93 |
op_doi |
https://doi.org/10.5194/bg-19-4431-2022 |
container_title |
Biogeosciences |
container_volume |
19 |
container_issue |
18 |
container_start_page |
4431 |
op_container_end_page |
4457 |
_version_ |
1766159360319291392 |