Limits and CO2 equilibration of near-coast alkalinity enhancement
Ocean Alkalinity Enhancement (OAE) has recently gained attention as a potential method for negative emissions at gigatonne scale, with near-coast OAE operations being economically favorable due to proximity to mineral and energy sources. In this paper we study critical questions which determine the...
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ftnonlinearchiv:oai:noa.gwlb.de:cop_mods_00061961 2023-05-15T18:25:53+02:00 Limits and CO2 equilibration of near-coast alkalinity enhancement He, Jing Tyka, Michael Dominik 2022-07 electronic https://doi.org/10.5194/egusphere-2022-683 https://noa.gwlb.de/receive/cop_mods_00061961 https://egusphere.copernicus.org/preprints/egusphere-2022-683/egusphere-2022-683.pdf eng eng Copernicus Publications https://doi.org/10.5194/egusphere-2022-683 https://noa.gwlb.de/receive/cop_mods_00061961 https://egusphere.copernicus.org/preprints/egusphere-2022-683/egusphere-2022-683.pdf https://creativecommons.org/licenses/by/4.0/ uneingeschränkt info:eu-repo/semantics/restrictedAccess CC-BY article Verlagsveröffentlichung article Text doc-type:article 2022 ftnonlinearchiv https://doi.org/10.5194/egusphere-2022-683 2022-07-31T23:11:44Z Ocean Alkalinity Enhancement (OAE) has recently gained attention as a potential method for negative emissions at gigatonne scale, with near-coast OAE operations being economically favorable due to proximity to mineral and energy sources. In this paper we study critical questions which determine the scale and viability of OAE: Which coastal locations are able to sustain a large flux of alkalinity at minimal pH and ΩArag (aragonite saturation) changes? What is the interference distance between adjacent OAE projects? How much CO2 is absorbed per unit of alkalinity added? How quickly does the induced CO2 deficiency equilibrate with the atmosphere? Using the LLC270 (0.3deg) ECCO global circulation model we find that the steady-state OAE rate varies over 1–2 orders of magnitude between different coasts and exhibits complex patterns and non-local dependencies which vary from region to region. In general, OAE in areas of strong coastal currents allow the largest fluxes and depending on the direction of coastal currents, neighboring OAE sites can exhibit dependencies as far as 400 km or more. We found that within relatively conservative constraints set on ∆pH or ∆Omega, most regional stretches of coastline are able to accommodate on the order of tens to hundreds of megatonnes of negative emissions within 300 km of the coast. We conclude that near-coastal OAE has the potential to scale globally to several GtCO2/yr of drawdown with conservative pH constraints, if the effort is spread over the majority of available coastlines. Depending on the location, we find a diverse set of equilibration kinetics, determined by the interplay of gas exchange and surface residence time. Most locations reach an uptake-efficiency plateau of 0.6–0.8mol CO2 per mol of alkalinity after 3–4 years, after which there is little further CO2 uptake. The most ideal locations, reaching an uptake of around 0.8 include north Madagascar, San Francisco, Brazil, Peru and locations close to the southern ocean such as Tasmania, Kerguelen and Patagonia, where ... Article in Journal/Newspaper Southern Ocean Niedersächsisches Online-Archiv NOA Kerguelen Patagonia Southern Ocean |
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Niedersächsisches Online-Archiv NOA |
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language |
English |
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article Verlagsveröffentlichung |
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article Verlagsveröffentlichung He, Jing Tyka, Michael Dominik Limits and CO2 equilibration of near-coast alkalinity enhancement |
topic_facet |
article Verlagsveröffentlichung |
description |
Ocean Alkalinity Enhancement (OAE) has recently gained attention as a potential method for negative emissions at gigatonne scale, with near-coast OAE operations being economically favorable due to proximity to mineral and energy sources. In this paper we study critical questions which determine the scale and viability of OAE: Which coastal locations are able to sustain a large flux of alkalinity at minimal pH and ΩArag (aragonite saturation) changes? What is the interference distance between adjacent OAE projects? How much CO2 is absorbed per unit of alkalinity added? How quickly does the induced CO2 deficiency equilibrate with the atmosphere? Using the LLC270 (0.3deg) ECCO global circulation model we find that the steady-state OAE rate varies over 1–2 orders of magnitude between different coasts and exhibits complex patterns and non-local dependencies which vary from region to region. In general, OAE in areas of strong coastal currents allow the largest fluxes and depending on the direction of coastal currents, neighboring OAE sites can exhibit dependencies as far as 400 km or more. We found that within relatively conservative constraints set on ∆pH or ∆Omega, most regional stretches of coastline are able to accommodate on the order of tens to hundreds of megatonnes of negative emissions within 300 km of the coast. We conclude that near-coastal OAE has the potential to scale globally to several GtCO2/yr of drawdown with conservative pH constraints, if the effort is spread over the majority of available coastlines. Depending on the location, we find a diverse set of equilibration kinetics, determined by the interplay of gas exchange and surface residence time. Most locations reach an uptake-efficiency plateau of 0.6–0.8mol CO2 per mol of alkalinity after 3–4 years, after which there is little further CO2 uptake. The most ideal locations, reaching an uptake of around 0.8 include north Madagascar, San Francisco, Brazil, Peru and locations close to the southern ocean such as Tasmania, Kerguelen and Patagonia, where ... |
format |
Article in Journal/Newspaper |
author |
He, Jing Tyka, Michael Dominik |
author_facet |
He, Jing Tyka, Michael Dominik |
author_sort |
He, Jing |
title |
Limits and CO2 equilibration of near-coast alkalinity enhancement |
title_short |
Limits and CO2 equilibration of near-coast alkalinity enhancement |
title_full |
Limits and CO2 equilibration of near-coast alkalinity enhancement |
title_fullStr |
Limits and CO2 equilibration of near-coast alkalinity enhancement |
title_full_unstemmed |
Limits and CO2 equilibration of near-coast alkalinity enhancement |
title_sort |
limits and co2 equilibration of near-coast alkalinity enhancement |
publisher |
Copernicus Publications |
publishDate |
2022 |
url |
https://doi.org/10.5194/egusphere-2022-683 https://noa.gwlb.de/receive/cop_mods_00061961 https://egusphere.copernicus.org/preprints/egusphere-2022-683/egusphere-2022-683.pdf |
geographic |
Kerguelen Patagonia Southern Ocean |
geographic_facet |
Kerguelen Patagonia Southern Ocean |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_relation |
https://doi.org/10.5194/egusphere-2022-683 https://noa.gwlb.de/receive/cop_mods_00061961 https://egusphere.copernicus.org/preprints/egusphere-2022-683/egusphere-2022-683.pdf |
op_rights |
https://creativecommons.org/licenses/by/4.0/ uneingeschränkt info:eu-repo/semantics/restrictedAccess |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.5194/egusphere-2022-683 |
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1766207582372888576 |