Age and chemistry of dissolved organic carbon reveal enhanced leaching of ancient labile carbon at the permafrost thaw zone
Climate change will alter the balance between frozen and thawed conditions in Arctic systems. Increased temperatures will make the extensive northern permafrost carbon stock vulnerable to decomposition and translocation. Production, cycling, and transport of dissolved organic carbon (DOC) are crucia...
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-19-1211-2022 https://noa.gwlb.de/receive/cop_mods_00060267 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00059914/bg-19-1211-2022.pdf https://bg.copernicus.org/articles/19/1211/2022/bg-19-1211-2022.pdf |
id |
ftnonlinearchiv:oai:noa.gwlb.de:cop_mods_00060267 |
---|---|
record_format |
openpolar |
spelling |
ftnonlinearchiv:oai:noa.gwlb.de:cop_mods_00060267 2023-05-15T14:55:44+02:00 Age and chemistry of dissolved organic carbon reveal enhanced leaching of ancient labile carbon at the permafrost thaw zone McFarlane, Karis J. Throckmorton, Heather M. Heikoop, Jeffrey M. Newman, Brent D. Hedgpeth, Alexandra L. Repasch, Marisa N. Guilderson, Thomas P. Wilson, Cathy J. 2022-02 electronic https://doi.org/10.5194/bg-19-1211-2022 https://noa.gwlb.de/receive/cop_mods_00060267 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00059914/bg-19-1211-2022.pdf https://bg.copernicus.org/articles/19/1211/2022/bg-19-1211-2022.pdf eng eng Copernicus Publications Biogeosciences -- http://www.bibliothek.uni-regensburg.de/ezeit/?2158181 -- http://www.copernicus.org/EGU/bg/bg.html -- 1726-4189 https://doi.org/10.5194/bg-19-1211-2022 https://noa.gwlb.de/receive/cop_mods_00060267 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00059914/bg-19-1211-2022.pdf https://bg.copernicus.org/articles/19/1211/2022/bg-19-1211-2022.pdf https://creativecommons.org/licenses/by/4.0/ uneingeschränkt info:eu-repo/semantics/openAccess CC-BY article Verlagsveröffentlichung article Text doc-type:article 2022 ftnonlinearchiv https://doi.org/10.5194/bg-19-1211-2022 2022-03-07T00:09:02Z Climate change will alter the balance between frozen and thawed conditions in Arctic systems. Increased temperatures will make the extensive northern permafrost carbon stock vulnerable to decomposition and translocation. Production, cycling, and transport of dissolved organic carbon (DOC) are crucial processes for high-latitude ecosystem carbon loss that result in considerable export off the Arctic landscape. To identify where and under what conditions permafrost DOC is mobilized in an Arctic headwater catchment, we measured radiocarbon (14C) of DOC and assessed DOC composition with ultraviolet–visible spectroscopy (UV–Vis) of surface waters and shallow and deep subsurface porewaters from 17 drainages in the Barrow Environmental Observatory in Alaska. Samples were collected in July and September 2013 to assess changes in age and chemistry of DOC over time. DOC age was highly variable ranging from modern (19 ‰ Δ14C) to approximately 7000 BP (−583 ‰ Δ14C). DOC age increased with depth, over the summer as the active layer deepened, and with increasing drainage size. DOC quality indicators reflected a DOC source rich in high molecular-weight and aromatic compounds, characteristics consistent with vegetation-derived organic matter that had undergone little microbial processing, throughout the summer and a weak relationship with DOC age. In deep porewaters, DOC age was also correlated with several biogeochemical indicators (including dissolved methane concentration, δ13C, and the apparent fractionation factor), suggesting a coupling between carbon and redox biogeochemistry influencing methane production. In the drained thawed lake basins included in this study, DOC concentrations and contributions of vegetation-derived organic matter declined with increasing basin age. The weak relationship between DOC age and chemistry and consistency in DOC chemical indicators over the summer suggest a high lability of old DOC released by thawing permafrost. Article in Journal/Newspaper Arctic Barrow Climate change permafrost Alaska Niedersächsisches Online-Archiv NOA Arctic Biogeosciences 19 4 1211 1223 |
institution |
Open Polar |
collection |
Niedersächsisches Online-Archiv NOA |
op_collection_id |
ftnonlinearchiv |
language |
English |
topic |
article Verlagsveröffentlichung |
spellingShingle |
article Verlagsveröffentlichung McFarlane, Karis J. Throckmorton, Heather M. Heikoop, Jeffrey M. Newman, Brent D. Hedgpeth, Alexandra L. Repasch, Marisa N. Guilderson, Thomas P. Wilson, Cathy J. Age and chemistry of dissolved organic carbon reveal enhanced leaching of ancient labile carbon at the permafrost thaw zone |
topic_facet |
article Verlagsveröffentlichung |
description |
Climate change will alter the balance between frozen and thawed conditions in Arctic systems. Increased temperatures will make the extensive northern permafrost carbon stock vulnerable to decomposition and translocation. Production, cycling, and transport of dissolved organic carbon (DOC) are crucial processes for high-latitude ecosystem carbon loss that result in considerable export off the Arctic landscape. To identify where and under what conditions permafrost DOC is mobilized in an Arctic headwater catchment, we measured radiocarbon (14C) of DOC and assessed DOC composition with ultraviolet–visible spectroscopy (UV–Vis) of surface waters and shallow and deep subsurface porewaters from 17 drainages in the Barrow Environmental Observatory in Alaska. Samples were collected in July and September 2013 to assess changes in age and chemistry of DOC over time. DOC age was highly variable ranging from modern (19 ‰ Δ14C) to approximately 7000 BP (−583 ‰ Δ14C). DOC age increased with depth, over the summer as the active layer deepened, and with increasing drainage size. DOC quality indicators reflected a DOC source rich in high molecular-weight and aromatic compounds, characteristics consistent with vegetation-derived organic matter that had undergone little microbial processing, throughout the summer and a weak relationship with DOC age. In deep porewaters, DOC age was also correlated with several biogeochemical indicators (including dissolved methane concentration, δ13C, and the apparent fractionation factor), suggesting a coupling between carbon and redox biogeochemistry influencing methane production. In the drained thawed lake basins included in this study, DOC concentrations and contributions of vegetation-derived organic matter declined with increasing basin age. The weak relationship between DOC age and chemistry and consistency in DOC chemical indicators over the summer suggest a high lability of old DOC released by thawing permafrost. |
format |
Article in Journal/Newspaper |
author |
McFarlane, Karis J. Throckmorton, Heather M. Heikoop, Jeffrey M. Newman, Brent D. Hedgpeth, Alexandra L. Repasch, Marisa N. Guilderson, Thomas P. Wilson, Cathy J. |
author_facet |
McFarlane, Karis J. Throckmorton, Heather M. Heikoop, Jeffrey M. Newman, Brent D. Hedgpeth, Alexandra L. Repasch, Marisa N. Guilderson, Thomas P. Wilson, Cathy J. |
author_sort |
McFarlane, Karis J. |
title |
Age and chemistry of dissolved organic carbon reveal enhanced leaching of ancient labile carbon at the permafrost thaw zone |
title_short |
Age and chemistry of dissolved organic carbon reveal enhanced leaching of ancient labile carbon at the permafrost thaw zone |
title_full |
Age and chemistry of dissolved organic carbon reveal enhanced leaching of ancient labile carbon at the permafrost thaw zone |
title_fullStr |
Age and chemistry of dissolved organic carbon reveal enhanced leaching of ancient labile carbon at the permafrost thaw zone |
title_full_unstemmed |
Age and chemistry of dissolved organic carbon reveal enhanced leaching of ancient labile carbon at the permafrost thaw zone |
title_sort |
age and chemistry of dissolved organic carbon reveal enhanced leaching of ancient labile carbon at the permafrost thaw zone |
publisher |
Copernicus Publications |
publishDate |
2022 |
url |
https://doi.org/10.5194/bg-19-1211-2022 https://noa.gwlb.de/receive/cop_mods_00060267 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00059914/bg-19-1211-2022.pdf https://bg.copernicus.org/articles/19/1211/2022/bg-19-1211-2022.pdf |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Barrow Climate change permafrost Alaska |
genre_facet |
Arctic Barrow Climate change permafrost Alaska |
op_relation |
Biogeosciences -- http://www.bibliothek.uni-regensburg.de/ezeit/?2158181 -- http://www.copernicus.org/EGU/bg/bg.html -- 1726-4189 https://doi.org/10.5194/bg-19-1211-2022 https://noa.gwlb.de/receive/cop_mods_00060267 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00059914/bg-19-1211-2022.pdf https://bg.copernicus.org/articles/19/1211/2022/bg-19-1211-2022.pdf |
op_rights |
https://creativecommons.org/licenses/by/4.0/ uneingeschränkt info:eu-repo/semantics/openAccess |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.5194/bg-19-1211-2022 |
container_title |
Biogeosciences |
container_volume |
19 |
container_issue |
4 |
container_start_page |
1211 |
op_container_end_page |
1223 |
_version_ |
1766327758771716096 |