Simulated Impact of Ocean Alkalinity Enhancement on Atmospheric CO2 Removal in the Bering Sea
Abstract Ocean alkalinity enhancement (OAE) has the potential to mitigate ocean acidification (OA) and induce atmospheric carbon dioxide (CO2) removal (CDR). We evaluate the CDR and OA mitigation impacts of a sustained point‐source OAE of 1.67 × 1010 mol total alkalinity (TA) yr−1 (equivalent to 667...
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ftdoajarticles:oai:doaj.org/article:a609c00950304a1d973c10714d274463 2023-05-15T15:43:18+02:00 Simulated Impact of Ocean Alkalinity Enhancement on Atmospheric CO2 Removal in the Bering Sea Hongjie Wang Darren J. Pilcher Kelly A. Kearney Jessica N. Cross O. Melissa Shugart Matthew D. Eisaman Brendan R. Carter 2023-01-01T00:00:00Z https://doi.org/10.1029/2022EF002816 https://doaj.org/article/a609c00950304a1d973c10714d274463 EN eng Wiley https://doi.org/10.1029/2022EF002816 https://doaj.org/toc/2328-4277 2328-4277 doi:10.1029/2022EF002816 https://doaj.org/article/a609c00950304a1d973c10714d274463 Earth's Future, Vol 11, Iss 1, Pp n/a-n/a (2023) single point‐source ocean alkalinity enhancement (OAE) electrochemical OAE carbon dioxide removal (CDR) ocean acidification mitigation Bering Sea carbon uptake efficiency Environmental sciences GE1-350 Ecology QH540-549.5 article 2023 ftdoajarticles https://doi.org/10.1029/2022EF002816 2023-01-29T01:26:13Z Abstract Ocean alkalinity enhancement (OAE) has the potential to mitigate ocean acidification (OA) and induce atmospheric carbon dioxide (CO2) removal (CDR). We evaluate the CDR and OA mitigation impacts of a sustained point‐source OAE of 1.67 × 1010 mol total alkalinity (TA) yr−1 (equivalent to 667,950 metric tons NaOH yr−1) in Unimak Pass, Alaska. We find the alkalinity elevation initially mitigates OA by decreasing pCO2 and increasing aragonite saturation state and pH. Then, enhanced air‐to‐sea CO2 exchange follows with an approximate e‐folding time scale of 5 weeks. Meaningful modeled OA mitigation with reductions of >10 μatm pCO2 (or just under 0.02 pH units) extends 100–100,000 km2 around the TA addition site. The CDR efficiency (i.e., the experimental seawater dissolved inorganic carbon (DIC) increase divided by the maximum DIC increase expected from the added TA) after the first 3 years is 0.96 ± 0.01, reflecting essentially complete air‐sea CO2 adjustment to the additional TA. This high efficiency is potentially a unique feature of the Bering Sea related to the shallow depths and mixed layer depths. The ratio of DIC increase to the TA added is also high (≥0.85) due to the high dissolved carbon content of seawater in the Bering Sea. The air‐sea gas exchange adjustment requires 3.6 months to become (>95%) complete, so the signal in dissolved carbon concentrations will likely be undetectable amid natural variability after dilution by ocean mixing. We therefore argue that modeling, on a range of scales, will need to play a major role in assessing the impacts of OAE interventions. Article in Journal/Newspaper Bering Sea Ocean acidification Alaska Directory of Open Access Journals: DOAJ Articles Bering Sea Earth's Future 11 1 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
single point‐source ocean alkalinity enhancement (OAE) electrochemical OAE carbon dioxide removal (CDR) ocean acidification mitigation Bering Sea carbon uptake efficiency Environmental sciences GE1-350 Ecology QH540-549.5 |
spellingShingle |
single point‐source ocean alkalinity enhancement (OAE) electrochemical OAE carbon dioxide removal (CDR) ocean acidification mitigation Bering Sea carbon uptake efficiency Environmental sciences GE1-350 Ecology QH540-549.5 Hongjie Wang Darren J. Pilcher Kelly A. Kearney Jessica N. Cross O. Melissa Shugart Matthew D. Eisaman Brendan R. Carter Simulated Impact of Ocean Alkalinity Enhancement on Atmospheric CO2 Removal in the Bering Sea |
topic_facet |
single point‐source ocean alkalinity enhancement (OAE) electrochemical OAE carbon dioxide removal (CDR) ocean acidification mitigation Bering Sea carbon uptake efficiency Environmental sciences GE1-350 Ecology QH540-549.5 |
description |
Abstract Ocean alkalinity enhancement (OAE) has the potential to mitigate ocean acidification (OA) and induce atmospheric carbon dioxide (CO2) removal (CDR). We evaluate the CDR and OA mitigation impacts of a sustained point‐source OAE of 1.67 × 1010 mol total alkalinity (TA) yr−1 (equivalent to 667,950 metric tons NaOH yr−1) in Unimak Pass, Alaska. We find the alkalinity elevation initially mitigates OA by decreasing pCO2 and increasing aragonite saturation state and pH. Then, enhanced air‐to‐sea CO2 exchange follows with an approximate e‐folding time scale of 5 weeks. Meaningful modeled OA mitigation with reductions of >10 μatm pCO2 (or just under 0.02 pH units) extends 100–100,000 km2 around the TA addition site. The CDR efficiency (i.e., the experimental seawater dissolved inorganic carbon (DIC) increase divided by the maximum DIC increase expected from the added TA) after the first 3 years is 0.96 ± 0.01, reflecting essentially complete air‐sea CO2 adjustment to the additional TA. This high efficiency is potentially a unique feature of the Bering Sea related to the shallow depths and mixed layer depths. The ratio of DIC increase to the TA added is also high (≥0.85) due to the high dissolved carbon content of seawater in the Bering Sea. The air‐sea gas exchange adjustment requires 3.6 months to become (>95%) complete, so the signal in dissolved carbon concentrations will likely be undetectable amid natural variability after dilution by ocean mixing. We therefore argue that modeling, on a range of scales, will need to play a major role in assessing the impacts of OAE interventions. |
format |
Article in Journal/Newspaper |
author |
Hongjie Wang Darren J. Pilcher Kelly A. Kearney Jessica N. Cross O. Melissa Shugart Matthew D. Eisaman Brendan R. Carter |
author_facet |
Hongjie Wang Darren J. Pilcher Kelly A. Kearney Jessica N. Cross O. Melissa Shugart Matthew D. Eisaman Brendan R. Carter |
author_sort |
Hongjie Wang |
title |
Simulated Impact of Ocean Alkalinity Enhancement on Atmospheric CO2 Removal in the Bering Sea |
title_short |
Simulated Impact of Ocean Alkalinity Enhancement on Atmospheric CO2 Removal in the Bering Sea |
title_full |
Simulated Impact of Ocean Alkalinity Enhancement on Atmospheric CO2 Removal in the Bering Sea |
title_fullStr |
Simulated Impact of Ocean Alkalinity Enhancement on Atmospheric CO2 Removal in the Bering Sea |
title_full_unstemmed |
Simulated Impact of Ocean Alkalinity Enhancement on Atmospheric CO2 Removal in the Bering Sea |
title_sort |
simulated impact of ocean alkalinity enhancement on atmospheric co2 removal in the bering sea |
publisher |
Wiley |
publishDate |
2023 |
url |
https://doi.org/10.1029/2022EF002816 https://doaj.org/article/a609c00950304a1d973c10714d274463 |
geographic |
Bering Sea |
geographic_facet |
Bering Sea |
genre |
Bering Sea Ocean acidification Alaska |
genre_facet |
Bering Sea Ocean acidification Alaska |
op_source |
Earth's Future, Vol 11, Iss 1, Pp n/a-n/a (2023) |
op_relation |
https://doi.org/10.1029/2022EF002816 https://doaj.org/toc/2328-4277 2328-4277 doi:10.1029/2022EF002816 https://doaj.org/article/a609c00950304a1d973c10714d274463 |
op_doi |
https://doi.org/10.1029/2022EF002816 |
container_title |
Earth's Future |
container_volume |
11 |
container_issue |
1 |
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1766377358987624448 |