Leakage of old carbon dioxide from a major river system in the Canadian Arctic
The Canadian Arctic is warming at an unprecedented rate. Warming-induced permafrost thaw can lead to mobilization of aged carbon from stores in soils and rocks. Tracking the carbon pools supplied to surrounding river networks provides insight on pathways and processes of greenhouse gas release. Here...
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Format: | Article in Journal/Newspaper |
Language: | English |
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Oxford University Press
2024
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Online Access: | https://doi.org/10.1093/pnasnexus/pgae134 https://ora.ox.ac.uk/objects/uuid:2d1aba72-36bb-4a15-8200-62b29222ee1a |
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ftuloxford:oai:ora.ox.ac.uk:uuid:2d1aba72-36bb-4a15-8200-62b29222ee1a 2024-09-09T19:21:06+00:00 Leakage of old carbon dioxide from a major river system in the Canadian Arctic Dasari, S Garnett, MH Hilton, RG 2024-04-25 https://doi.org/10.1093/pnasnexus/pgae134 https://ora.ox.ac.uk/objects/uuid:2d1aba72-36bb-4a15-8200-62b29222ee1a eng eng Oxford University Press doi:10.1093/pnasnexus/pgae134 https://ora.ox.ac.uk/objects/uuid:2d1aba72-36bb-4a15-8200-62b29222ee1a https://doi.org/10.1093/pnasnexus/pgae134 info:eu-repo/semantics/openAccess CC Attribution (CC BY) Journal article 2024 ftuloxford https://doi.org/10.1093/pnasnexus/pgae134 2024-08-05T14:07:49Z The Canadian Arctic is warming at an unprecedented rate. Warming-induced permafrost thaw can lead to mobilization of aged carbon from stores in soils and rocks. Tracking the carbon pools supplied to surrounding river networks provides insight on pathways and processes of greenhouse gas release. Here, we investigated the dual-carbon isotopic characteristics of the dissolved inorganic carbon (DIC) pool in the main stem and tributaries of the Mackenzie River system. The radiocarbon (14C) activity of DIC shows export of “old” carbon (2,380 ± 1,040 14C years BP on average) occurred during summer in sampling years. The stable isotope composition of river DIC implicates degassing of aged carbon as CO2 from riverine tributaries during transport to the delta; however, information on potential drivers and fluxes are still lacking. Accounting for stable isotope fractionation during CO2 loss, we show that a large proportion of this aged carbon (60 ± 10%) may have been sourced from biospheric organic carbon oxidation, with other inputs from carbonate weathering pathways and atmospheric exchange. The findings highlight hydrologically connected waters as viable pathways for mobilization of aged carbon pools from Arctic permafrost soils. Article in Journal/Newspaper Arctic Mackenzie river permafrost ORA - Oxford University Research Archive Arctic Mackenzie River PNAS Nexus 3 4 |
institution |
Open Polar |
collection |
ORA - Oxford University Research Archive |
op_collection_id |
ftuloxford |
language |
English |
description |
The Canadian Arctic is warming at an unprecedented rate. Warming-induced permafrost thaw can lead to mobilization of aged carbon from stores in soils and rocks. Tracking the carbon pools supplied to surrounding river networks provides insight on pathways and processes of greenhouse gas release. Here, we investigated the dual-carbon isotopic characteristics of the dissolved inorganic carbon (DIC) pool in the main stem and tributaries of the Mackenzie River system. The radiocarbon (14C) activity of DIC shows export of “old” carbon (2,380 ± 1,040 14C years BP on average) occurred during summer in sampling years. The stable isotope composition of river DIC implicates degassing of aged carbon as CO2 from riverine tributaries during transport to the delta; however, information on potential drivers and fluxes are still lacking. Accounting for stable isotope fractionation during CO2 loss, we show that a large proportion of this aged carbon (60 ± 10%) may have been sourced from biospheric organic carbon oxidation, with other inputs from carbonate weathering pathways and atmospheric exchange. The findings highlight hydrologically connected waters as viable pathways for mobilization of aged carbon pools from Arctic permafrost soils. |
format |
Article in Journal/Newspaper |
author |
Dasari, S Garnett, MH Hilton, RG |
spellingShingle |
Dasari, S Garnett, MH Hilton, RG Leakage of old carbon dioxide from a major river system in the Canadian Arctic |
author_facet |
Dasari, S Garnett, MH Hilton, RG |
author_sort |
Dasari, S |
title |
Leakage of old carbon dioxide from a major river system in the Canadian Arctic |
title_short |
Leakage of old carbon dioxide from a major river system in the Canadian Arctic |
title_full |
Leakage of old carbon dioxide from a major river system in the Canadian Arctic |
title_fullStr |
Leakage of old carbon dioxide from a major river system in the Canadian Arctic |
title_full_unstemmed |
Leakage of old carbon dioxide from a major river system in the Canadian Arctic |
title_sort |
leakage of old carbon dioxide from a major river system in the canadian arctic |
publisher |
Oxford University Press |
publishDate |
2024 |
url |
https://doi.org/10.1093/pnasnexus/pgae134 https://ora.ox.ac.uk/objects/uuid:2d1aba72-36bb-4a15-8200-62b29222ee1a |
geographic |
Arctic Mackenzie River |
geographic_facet |
Arctic Mackenzie River |
genre |
Arctic Mackenzie river permafrost |
genre_facet |
Arctic Mackenzie river permafrost |
op_relation |
doi:10.1093/pnasnexus/pgae134 https://ora.ox.ac.uk/objects/uuid:2d1aba72-36bb-4a15-8200-62b29222ee1a https://doi.org/10.1093/pnasnexus/pgae134 |
op_rights |
info:eu-repo/semantics/openAccess CC Attribution (CC BY) |
op_doi |
https://doi.org/10.1093/pnasnexus/pgae134 |
container_title |
PNAS Nexus |
container_volume |
3 |
container_issue |
4 |
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1809761305106579456 |