Controls on the 14C Content of Dissolved and Particulate Organic Carbon Mobilized Across the Mackenzie River Basin, Canada
The Mackenzie River Basin (MRB) delivers large quantities of organic carbon (OC) into the Arctic Ocean, with significant implications for the global C budgets and ocean biogeochemistry. The amount and properties of OC in the Mackenzie River's delta have been well monitored in the last decade, b...
Published in: | Global Biogeochemical Cycles |
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ftnrm:oai:DiVA.org:nrm-4027 2023-05-15T15:00:58+02:00 Controls on the 14C Content of Dissolved and Particulate Organic Carbon Mobilized Across the Mackenzie River Basin, Canada Campeau, Aydrey Soerensen, Anne L. Martma, T Åkeblom, Staffan Zdanowicz, Christian 2020 application/pdf http://urn.kb.se/resolve?urn=urn:nbn:se:nrm:diva-4027 https://doi.org/10.1029/2020GB006671 eng eng Enheten för miljöforskning och övervakning Uppsala University Tallinn University of Technology Statistic Sweden Global Biogeochemical Cycles, 0886-6236, 2020, 34:12, http://urn.kb.se/resolve?urn=urn:nbn:se:nrm:diva-4027 doi:10.1029/2020GB006671 info:eu-repo/semantics/openAccess arctic rivers dissolved organic carbon particulate organic carbon radiocarbon Other Earth and Related Environmental Sciences Annan geovetenskap och miljövetenskap Article in journal info:eu-repo/semantics/article text 2020 ftnrm https://doi.org/10.1029/2020GB006671 2021-10-08T07:21:22Z The Mackenzie River Basin (MRB) delivers large quantities of organic carbon (OC) into the Arctic Ocean, with significant implications for the global C budgets and ocean biogeochemistry. The amount and properties of OC in the Mackenzie River's delta have been well monitored in the last decade, but the spatial variability in OC sources transported by its different tributaries is still unclear. Here we present new data on the radiocarbon (14C) content of dissolved and particulate OC (Δ14C‐DOC and Δ14C‐POC) across the mainstem and major tributaries of the MRB, comprising 19 different locations, to identify factors controlling spatial patterns in riverine OC sources. The Δ14C‐DOC and Δ14C‐POC varied across a large range, from −179.9‰ to 62.9‰, and −728.8‰ to −9.0‰, respectively. Our data reveal a positive spatial coupling between the Δ14C of DOC and POC across the MRB, whereby the most 14C‐depleted waters were issued from the mountainous west bank of the MRB. This 14C‐depleted DOC and POC likely originates from a combination of petrogenic sources, connected with the presence of kerogens in the bedrock, and biogenic sources, mobilized by thawing permafrost. Our analysis also reveals intriguing relationships between Δ14C of DOC and POC with turbidity, water stable isotope ratio and catchment elevation, indicating that hydrology and geomorphology are key to understanding riverine OC sources in this landscape. A closer examination of the specific mechanisms giving rise to these relationships is recommended. For now, this study provides a road map of the key OC sources in this rapidly changing river basin. Article in Journal/Newspaper Arctic Arctic Ocean Mackenzie river permafrost Swedish Museum of Natural History: Publications (DiVA) Arctic Arctic Ocean Mackenzie River Canada Global Biogeochemical Cycles 34 12 |
institution |
Open Polar |
collection |
Swedish Museum of Natural History: Publications (DiVA) |
op_collection_id |
ftnrm |
language |
English |
topic |
arctic rivers dissolved organic carbon particulate organic carbon radiocarbon Other Earth and Related Environmental Sciences Annan geovetenskap och miljövetenskap |
spellingShingle |
arctic rivers dissolved organic carbon particulate organic carbon radiocarbon Other Earth and Related Environmental Sciences Annan geovetenskap och miljövetenskap Campeau, Aydrey Soerensen, Anne L. Martma, T Åkeblom, Staffan Zdanowicz, Christian Controls on the 14C Content of Dissolved and Particulate Organic Carbon Mobilized Across the Mackenzie River Basin, Canada |
topic_facet |
arctic rivers dissolved organic carbon particulate organic carbon radiocarbon Other Earth and Related Environmental Sciences Annan geovetenskap och miljövetenskap |
description |
The Mackenzie River Basin (MRB) delivers large quantities of organic carbon (OC) into the Arctic Ocean, with significant implications for the global C budgets and ocean biogeochemistry. The amount and properties of OC in the Mackenzie River's delta have been well monitored in the last decade, but the spatial variability in OC sources transported by its different tributaries is still unclear. Here we present new data on the radiocarbon (14C) content of dissolved and particulate OC (Δ14C‐DOC and Δ14C‐POC) across the mainstem and major tributaries of the MRB, comprising 19 different locations, to identify factors controlling spatial patterns in riverine OC sources. The Δ14C‐DOC and Δ14C‐POC varied across a large range, from −179.9‰ to 62.9‰, and −728.8‰ to −9.0‰, respectively. Our data reveal a positive spatial coupling between the Δ14C of DOC and POC across the MRB, whereby the most 14C‐depleted waters were issued from the mountainous west bank of the MRB. This 14C‐depleted DOC and POC likely originates from a combination of petrogenic sources, connected with the presence of kerogens in the bedrock, and biogenic sources, mobilized by thawing permafrost. Our analysis also reveals intriguing relationships between Δ14C of DOC and POC with turbidity, water stable isotope ratio and catchment elevation, indicating that hydrology and geomorphology are key to understanding riverine OC sources in this landscape. A closer examination of the specific mechanisms giving rise to these relationships is recommended. For now, this study provides a road map of the key OC sources in this rapidly changing river basin. |
format |
Article in Journal/Newspaper |
author |
Campeau, Aydrey Soerensen, Anne L. Martma, T Åkeblom, Staffan Zdanowicz, Christian |
author_facet |
Campeau, Aydrey Soerensen, Anne L. Martma, T Åkeblom, Staffan Zdanowicz, Christian |
author_sort |
Campeau, Aydrey |
title |
Controls on the 14C Content of Dissolved and Particulate Organic Carbon Mobilized Across the Mackenzie River Basin, Canada |
title_short |
Controls on the 14C Content of Dissolved and Particulate Organic Carbon Mobilized Across the Mackenzie River Basin, Canada |
title_full |
Controls on the 14C Content of Dissolved and Particulate Organic Carbon Mobilized Across the Mackenzie River Basin, Canada |
title_fullStr |
Controls on the 14C Content of Dissolved and Particulate Organic Carbon Mobilized Across the Mackenzie River Basin, Canada |
title_full_unstemmed |
Controls on the 14C Content of Dissolved and Particulate Organic Carbon Mobilized Across the Mackenzie River Basin, Canada |
title_sort |
controls on the 14c content of dissolved and particulate organic carbon mobilized across the mackenzie river basin, canada |
publisher |
Enheten för miljöforskning och övervakning |
publishDate |
2020 |
url |
http://urn.kb.se/resolve?urn=urn:nbn:se:nrm:diva-4027 https://doi.org/10.1029/2020GB006671 |
geographic |
Arctic Arctic Ocean Mackenzie River Canada |
geographic_facet |
Arctic Arctic Ocean Mackenzie River Canada |
genre |
Arctic Arctic Ocean Mackenzie river permafrost |
genre_facet |
Arctic Arctic Ocean Mackenzie river permafrost |
op_relation |
Global Biogeochemical Cycles, 0886-6236, 2020, 34:12, http://urn.kb.se/resolve?urn=urn:nbn:se:nrm:diva-4027 doi:10.1029/2020GB006671 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1029/2020GB006671 |
container_title |
Global Biogeochemical Cycles |
container_volume |
34 |
container_issue |
12 |
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1766333010860310528 |