Arctic Permafrost Thawing Enhances Sulfide Oxidation
Permafrost degradation is altering biogeochemical processes throughout the Arctic. Thaw-induced changes in organic matter transformations and mineral weathering reactions are impacting fluxes of inorganic carbon (IC) and alkalinity (ALK) in Arctic rivers. However, the net impact of these changing fl...
Published in: | Global Biogeochemical Cycles |
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ftcaltechauth:oai:authors.library.caltech.edu:7sk0g-48t54 2024-09-15T18:29:47+00:00 Arctic Permafrost Thawing Enhances Sulfide Oxidation Kemeny, Preston Cosslett Li, Gen K. Douglas, Madison Berelson, William Chadwick, Austin J. Dalleska, Nathan F. Lamb, Michael P. Larsen, William Magyar, John S. Rollins, Nick E. Rowland, Joel Smith, M. Isabel Torres, Mark A. Webb, Samuel M. Fischer, Woodward W. West, A. Joshua 2023-11 https://doi.org/10.1029/2022gb007644 eng eng American Geophysical Union https://doi.org/10.1029/2022gb007644 oai:authors.library.caltech.edu:7sk0g-48t54 issn:1944-9224 info:eu-repo/semantics/openAccess Creative Commons Attribution Non Commercial 4.0 International https://creativecommons.org/licenses/by-nc/4.0/legalcode Global Biogeochemical Cycles, 37(11), e2022GB007644, (2023-11) info:eu-repo/semantics/article 2023 ftcaltechauth https://doi.org/10.1029/2022gb007644 2024-08-06T15:35:04Z Permafrost degradation is altering biogeochemical processes throughout the Arctic. Thaw-induced changes in organic matter transformations and mineral weathering reactions are impacting fluxes of inorganic carbon (IC) and alkalinity (ALK) in Arctic rivers. However, the net impact of these changing fluxes on the concentration of carbon dioxide in the atmosphere (pCO2) is relatively unconstrained. Resolving this uncertainty is important as thaw-driven changes in the fluxes of IC and ALK could produce feedbacks in the global carbon cycle. Enhanced production of sulfuric acid through sulfide oxidation is particularly poorly quantified despite its potential to remove ALK from the ocean-atmosphere system and increasepCO2, producing a positive feedback leading to more warming and permafrost degradation. In this work, we quantified weathering in the Koyukuk River, a major tributary of the Yukon River draining discontinuous permafrost in central Alaska, based on water and sediment samples collected near the village of Huslia in summer 2018. Using measurements of major ion abundances and sulfate (SOâ‚„²â») sulfur (34S/32S) and oxygen (18O/16O) isotope ratios, we employed the MEANDIR inversion model to quantify the relative importance of a suite of weathering processes and their net impact onpCO2. Calculations found that approximately 80% of SO4²â» in mainstem samples derived from sulfide oxidation with the remainder from evaporite dissolution. Moreover,34S/32S ratios,13C/12C ratios of dissolved IC, and sulfur X-ray absorption spectra of mainstem, secondary channel, and floodplain pore fluid and sediment samples revealed modest degrees of microbial sulfate reduction within the floodplain. Weathering fluxes of ALK and IC result in lower values ofpCO2over timescales shorter than carbonate compensation (∼104yr) and, for mainstem samples, higher values ofpCO2 over timescales longer than carbonate compensation but shorter than the residence time of marine SOâ‚„²â» (∼107 yr). Furthermore, the absolute ... Article in Journal/Newspaper permafrost Yukon river Alaska Yukon Caltech Authors (California Institute of Technology) Global Biogeochemical Cycles 37 11 |
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Caltech Authors (California Institute of Technology) |
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ftcaltechauth |
language |
English |
description |
Permafrost degradation is altering biogeochemical processes throughout the Arctic. Thaw-induced changes in organic matter transformations and mineral weathering reactions are impacting fluxes of inorganic carbon (IC) and alkalinity (ALK) in Arctic rivers. However, the net impact of these changing fluxes on the concentration of carbon dioxide in the atmosphere (pCO2) is relatively unconstrained. Resolving this uncertainty is important as thaw-driven changes in the fluxes of IC and ALK could produce feedbacks in the global carbon cycle. Enhanced production of sulfuric acid through sulfide oxidation is particularly poorly quantified despite its potential to remove ALK from the ocean-atmosphere system and increasepCO2, producing a positive feedback leading to more warming and permafrost degradation. In this work, we quantified weathering in the Koyukuk River, a major tributary of the Yukon River draining discontinuous permafrost in central Alaska, based on water and sediment samples collected near the village of Huslia in summer 2018. Using measurements of major ion abundances and sulfate (SOâ‚„²â») sulfur (34S/32S) and oxygen (18O/16O) isotope ratios, we employed the MEANDIR inversion model to quantify the relative importance of a suite of weathering processes and their net impact onpCO2. Calculations found that approximately 80% of SO4²â» in mainstem samples derived from sulfide oxidation with the remainder from evaporite dissolution. Moreover,34S/32S ratios,13C/12C ratios of dissolved IC, and sulfur X-ray absorption spectra of mainstem, secondary channel, and floodplain pore fluid and sediment samples revealed modest degrees of microbial sulfate reduction within the floodplain. Weathering fluxes of ALK and IC result in lower values ofpCO2over timescales shorter than carbonate compensation (∼104yr) and, for mainstem samples, higher values ofpCO2 over timescales longer than carbonate compensation but shorter than the residence time of marine SOâ‚„²â» (∼107 yr). Furthermore, the absolute ... |
format |
Article in Journal/Newspaper |
author |
Kemeny, Preston Cosslett Li, Gen K. Douglas, Madison Berelson, William Chadwick, Austin J. Dalleska, Nathan F. Lamb, Michael P. Larsen, William Magyar, John S. Rollins, Nick E. Rowland, Joel Smith, M. Isabel Torres, Mark A. Webb, Samuel M. Fischer, Woodward W. West, A. Joshua |
spellingShingle |
Kemeny, Preston Cosslett Li, Gen K. Douglas, Madison Berelson, William Chadwick, Austin J. Dalleska, Nathan F. Lamb, Michael P. Larsen, William Magyar, John S. Rollins, Nick E. Rowland, Joel Smith, M. Isabel Torres, Mark A. Webb, Samuel M. Fischer, Woodward W. West, A. Joshua Arctic Permafrost Thawing Enhances Sulfide Oxidation |
author_facet |
Kemeny, Preston Cosslett Li, Gen K. Douglas, Madison Berelson, William Chadwick, Austin J. Dalleska, Nathan F. Lamb, Michael P. Larsen, William Magyar, John S. Rollins, Nick E. Rowland, Joel Smith, M. Isabel Torres, Mark A. Webb, Samuel M. Fischer, Woodward W. West, A. Joshua |
author_sort |
Kemeny, Preston Cosslett |
title |
Arctic Permafrost Thawing Enhances Sulfide Oxidation |
title_short |
Arctic Permafrost Thawing Enhances Sulfide Oxidation |
title_full |
Arctic Permafrost Thawing Enhances Sulfide Oxidation |
title_fullStr |
Arctic Permafrost Thawing Enhances Sulfide Oxidation |
title_full_unstemmed |
Arctic Permafrost Thawing Enhances Sulfide Oxidation |
title_sort |
arctic permafrost thawing enhances sulfide oxidation |
publisher |
American Geophysical Union |
publishDate |
2023 |
url |
https://doi.org/10.1029/2022gb007644 |
genre |
permafrost Yukon river Alaska Yukon |
genre_facet |
permafrost Yukon river Alaska Yukon |
op_source |
Global Biogeochemical Cycles, 37(11), e2022GB007644, (2023-11) |
op_relation |
https://doi.org/10.1029/2022gb007644 oai:authors.library.caltech.edu:7sk0g-48t54 issn:1944-9224 |
op_rights |
info:eu-repo/semantics/openAccess Creative Commons Attribution Non Commercial 4.0 International https://creativecommons.org/licenses/by-nc/4.0/legalcode |
op_doi |
https://doi.org/10.1029/2022gb007644 |
container_title |
Global Biogeochemical Cycles |
container_volume |
37 |
container_issue |
11 |
_version_ |
1810471219346014208 |