A numerical assessment of ocean alkalinity enhancement efficiency on a river-dominated continental shelf—a case study in the northern Gulf of Mexico
A robust high-resolution coupled hydrodynamic-biogeochemical model was applied to the northern Gulf of Mexico to assess the efficiency of river- and ocean-sourced ocean alkalinity enhancement (OAE). Sensitivity tests indicate that the effectiveness of OAE-induced CO _2 uptake is primarily influenced...
Saved in:
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
IOP Publishing
2025-01-01
|
| Series: | Environmental Research Letters |
| Subjects: | |
| Online Access: | https://doi.org/10.1088/1748-9326/adaa8b |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1832589545761144832 |
|---|---|
| author | Yanda Ou Z George Xue Xinping Hu |
| author_facet | Yanda Ou Z George Xue Xinping Hu |
| author_sort | Yanda Ou |
| collection | DOAJ |
| description | A robust high-resolution coupled hydrodynamic-biogeochemical model was applied to the northern Gulf of Mexico to assess the efficiency of river- and ocean-sourced ocean alkalinity enhancement (OAE). Sensitivity tests indicate that the effectiveness of OAE-induced CO _2 uptake is primarily influenced by the amount of alkalinity introduced and local wind-driven mixing, with the former determining the overall uptake and the latter affecting short-term variability. Compared to ocean-sourced OAE (direct ocean release), river-sourced OAE (elevated river alkalinity) is more effective and sustainable. River-sourced OAE has higher CO _2 uptake efficiency with reduced spatial and temporal uncertainty and greater overall CO _2 uptake. For river-sourced OAE, surface pH increases pronouncedly near the mouths of the Mississippi River. The ideal OAE implementation time includes spring, early summer, fall, and winter. Mid and late-summer implementation is not recommended due to weak mixing, which results in less alkalinity dispersal and greater pH variability. In addition, while the aragonite saturation state generally remains below 6 around the Mississippi River plume, it increases pronouncedly during mid to late summer, risking alkalinity loss due to CaCO _3 precipitation and reduced CO _2 uptake efficiency near river mouths. Scaling OAE-induced CO _2 uptake to the 25 largest rivers in the world indicates that increasing riverine alkalinity concentrations by 10% could remove 23.23 megatons of CO _2 annually, meeting 0.37%–0.61% of the 2025–2030 CO _2 removal target. |
| format | Article |
| id | doaj-art-77804770ddfe448ead4e44dca131e01b |
| institution | Kabale University |
| issn | 1748-9326 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | Environmental Research Letters |
| spelling | doaj-art-77804770ddfe448ead4e44dca131e01b2025-01-24T12:05:51ZengIOP PublishingEnvironmental Research Letters1748-93262025-01-0120202403110.1088/1748-9326/adaa8bA numerical assessment of ocean alkalinity enhancement efficiency on a river-dominated continental shelf—a case study in the northern Gulf of MexicoYanda Ou0https://orcid.org/0000-0001-6200-8946Z George Xue1https://orcid.org/0000-0003-4018-0248Xinping Hu2https://orcid.org/0000-0002-0613-6545Department of Oceanography and Coastal Sciences, Louisiana State University , Baton Rouge, LA, United States of America; Center for Computation and Technology, Louisiana State University , Baton Rouge, LA, United States of AmericaDepartment of Oceanography and Coastal Sciences, Louisiana State University , Baton Rouge, LA, United States of America; Center for Computation and Technology, Louisiana State University , Baton Rouge, LA, United States of America; Coastal Studies Institute, Louisiana State University , Baton Rouge, LA, United States of AmericaMarine Science Institute , The University of Texas at Austin, Port Aransas, TX, United States of AmericaA robust high-resolution coupled hydrodynamic-biogeochemical model was applied to the northern Gulf of Mexico to assess the efficiency of river- and ocean-sourced ocean alkalinity enhancement (OAE). Sensitivity tests indicate that the effectiveness of OAE-induced CO _2 uptake is primarily influenced by the amount of alkalinity introduced and local wind-driven mixing, with the former determining the overall uptake and the latter affecting short-term variability. Compared to ocean-sourced OAE (direct ocean release), river-sourced OAE (elevated river alkalinity) is more effective and sustainable. River-sourced OAE has higher CO _2 uptake efficiency with reduced spatial and temporal uncertainty and greater overall CO _2 uptake. For river-sourced OAE, surface pH increases pronouncedly near the mouths of the Mississippi River. The ideal OAE implementation time includes spring, early summer, fall, and winter. Mid and late-summer implementation is not recommended due to weak mixing, which results in less alkalinity dispersal and greater pH variability. In addition, while the aragonite saturation state generally remains below 6 around the Mississippi River plume, it increases pronouncedly during mid to late summer, risking alkalinity loss due to CaCO _3 precipitation and reduced CO _2 uptake efficiency near river mouths. Scaling OAE-induced CO _2 uptake to the 25 largest rivers in the world indicates that increasing riverine alkalinity concentrations by 10% could remove 23.23 megatons of CO _2 annually, meeting 0.37%–0.61% of the 2025–2030 CO _2 removal target.https://doi.org/10.1088/1748-9326/adaa8bhigh-fidelity regional modelGulf of MexicoMississippi riverriver-sourced OAEocean-sourced OAE |
| spellingShingle | Yanda Ou Z George Xue Xinping Hu A numerical assessment of ocean alkalinity enhancement efficiency on a river-dominated continental shelf—a case study in the northern Gulf of Mexico Environmental Research Letters high-fidelity regional model Gulf of Mexico Mississippi river river-sourced OAE ocean-sourced OAE |
| title | A numerical assessment of ocean alkalinity enhancement efficiency on a river-dominated continental shelf—a case study in the northern Gulf of Mexico |
| title_full | A numerical assessment of ocean alkalinity enhancement efficiency on a river-dominated continental shelf—a case study in the northern Gulf of Mexico |
| title_fullStr | A numerical assessment of ocean alkalinity enhancement efficiency on a river-dominated continental shelf—a case study in the northern Gulf of Mexico |
| title_full_unstemmed | A numerical assessment of ocean alkalinity enhancement efficiency on a river-dominated continental shelf—a case study in the northern Gulf of Mexico |
| title_short | A numerical assessment of ocean alkalinity enhancement efficiency on a river-dominated continental shelf—a case study in the northern Gulf of Mexico |
| title_sort | numerical assessment of ocean alkalinity enhancement efficiency on a river dominated continental shelf a case study in the northern gulf of mexico |
| topic | high-fidelity regional model Gulf of Mexico Mississippi river river-sourced OAE ocean-sourced OAE |
| url | https://doi.org/10.1088/1748-9326/adaa8b |
| work_keys_str_mv | AT yandaou anumericalassessmentofoceanalkalinityenhancementefficiencyonariverdominatedcontinentalshelfacasestudyinthenortherngulfofmexico AT zgeorgexue anumericalassessmentofoceanalkalinityenhancementefficiencyonariverdominatedcontinentalshelfacasestudyinthenortherngulfofmexico AT xinpinghu anumericalassessmentofoceanalkalinityenhancementefficiencyonariverdominatedcontinentalshelfacasestudyinthenortherngulfofmexico AT yandaou numericalassessmentofoceanalkalinityenhancementefficiencyonariverdominatedcontinentalshelfacasestudyinthenortherngulfofmexico AT zgeorgexue numericalassessmentofoceanalkalinityenhancementefficiencyonariverdominatedcontinentalshelfacasestudyinthenortherngulfofmexico AT xinpinghu numericalassessmentofoceanalkalinityenhancementefficiencyonariverdominatedcontinentalshelfacasestudyinthenortherngulfofmexico |