Contrasts in dissolved, particulate and sedimentary organic carbon from the Kolyma River to the East Siberian Shelf
Arctic rivers will be increasingly affected by the hydrological and biogeochemical consequences of thawing permafrost. During transport, permafrost-derived organic carbon (OC) can either accumulate in floodplain and shelf sediments or be degraded into greenhouse gases prior to final burial. Thus, th...
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ftethz:oai:www.research-collection.ethz.ch:20.500.11850/593091 2023-05-15T15:01:54+02:00 Contrasts in dissolved, particulate and sedimentary organic carbon from the Kolyma River to the East Siberian Shelf Jong, Dirk Bröder, Lisa Tesi, Tommaso Keskitalo, Kirsi H. Zimov, Nikita Davydova, Anna Pika, Philip Haghipour, Negar Eglinton, Timothy I. Vonk, Jorien E. 2022-06-27 application/application/pdf https://hdl.handle.net/20.500.11850/593091 https://doi.org/10.3929/ethz-b-000593091 en eng Copernicus info:eu-repo/semantics/altIdentifier/doi/10.5194/egusphere-2022-516 http://hdl.handle.net/20.500.11850/593091 doi:10.3929/ethz-b-000593091 info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/4.0/ Creative Commons Attribution 4.0 International CC-BY EGUsphere info:eu-repo/semantics/workingPaper 2022 ftethz https://doi.org/20.500.11850/593091 https://doi.org/10.3929/ethz-b-000593091 https://doi.org/10.5194/egusphere-2022-516 2023-02-20T00:41:01Z Arctic rivers will be increasingly affected by the hydrological and biogeochemical consequences of thawing permafrost. During transport, permafrost-derived organic carbon (OC) can either accumulate in floodplain and shelf sediments or be degraded into greenhouse gases prior to final burial. Thus, the net impact of permafrost OC on climate will ultimately depend on the interplay of complex processes that occur along the source-to-sink system. Here, we focused on the Kolyma River, the largest watershed completely underlain by continuous permafrost, and marine sediments of the East Siberian Sea as a transect to investigate the fate of permafrost OC along the land-ocean continuum. Three pools of riverine OC were investigated for the Kolyma main stem and five of its tributaries: dissolved OC (DOC), suspended particulate OC (POC), and riverbed sediment OC (SOC) and compared to earlier findings in marine sediments. Carbon isotopes (δ13C, Δ14C), lignin phenol, and lipid biomarkers show a contrasting composition and degradation state of these different carbon pools. Dual isotope source apportionment calculations imply that old permafrost-OC is mostly associated with sediments (SOC; contribution of 68 ± 10 %), and less dominant in POC (38 ± 8 %), while autochthonous primary production contributes around 44 ± 10 % to POC in the main stem and up to 79 ± 11 % in tributaries. Biomarker degradation indices suggest that Kolyma DOC is relatively degraded, regardless of its generally young age shown by previous studies. In contrast, SOC shows the lowest Δ14C signal (oldest OC), yet relatively fresh compositional signatures. Furthermore, decreasing mineral surface area-normalised OC- and biomarker loadings suggest that SOC is reactive along the land-ocean continuum supporting the idea that floodplain and shelf sediments are efficient reactors. A better understanding of DOC and POC dynamics in Arctic rivers is still necessary, however, this study highlights that sedimentary dynamics play a crucial role when targeting ... Report Arctic East Siberian Sea kolyma river permafrost ETH Zürich Research Collection Arctic Kolyma ENVELOPE(161.000,161.000,69.500,69.500) East Siberian Sea ENVELOPE(166.000,166.000,74.000,74.000) East Siberian Shelf ENVELOPE(-162.267,-162.267,74.400,74.400) |
institution |
Open Polar |
collection |
ETH Zürich Research Collection |
op_collection_id |
ftethz |
language |
English |
description |
Arctic rivers will be increasingly affected by the hydrological and biogeochemical consequences of thawing permafrost. During transport, permafrost-derived organic carbon (OC) can either accumulate in floodplain and shelf sediments or be degraded into greenhouse gases prior to final burial. Thus, the net impact of permafrost OC on climate will ultimately depend on the interplay of complex processes that occur along the source-to-sink system. Here, we focused on the Kolyma River, the largest watershed completely underlain by continuous permafrost, and marine sediments of the East Siberian Sea as a transect to investigate the fate of permafrost OC along the land-ocean continuum. Three pools of riverine OC were investigated for the Kolyma main stem and five of its tributaries: dissolved OC (DOC), suspended particulate OC (POC), and riverbed sediment OC (SOC) and compared to earlier findings in marine sediments. Carbon isotopes (δ13C, Δ14C), lignin phenol, and lipid biomarkers show a contrasting composition and degradation state of these different carbon pools. Dual isotope source apportionment calculations imply that old permafrost-OC is mostly associated with sediments (SOC; contribution of 68 ± 10 %), and less dominant in POC (38 ± 8 %), while autochthonous primary production contributes around 44 ± 10 % to POC in the main stem and up to 79 ± 11 % in tributaries. Biomarker degradation indices suggest that Kolyma DOC is relatively degraded, regardless of its generally young age shown by previous studies. In contrast, SOC shows the lowest Δ14C signal (oldest OC), yet relatively fresh compositional signatures. Furthermore, decreasing mineral surface area-normalised OC- and biomarker loadings suggest that SOC is reactive along the land-ocean continuum supporting the idea that floodplain and shelf sediments are efficient reactors. A better understanding of DOC and POC dynamics in Arctic rivers is still necessary, however, this study highlights that sedimentary dynamics play a crucial role when targeting ... |
format |
Report |
author |
Jong, Dirk Bröder, Lisa Tesi, Tommaso Keskitalo, Kirsi H. Zimov, Nikita Davydova, Anna Pika, Philip Haghipour, Negar Eglinton, Timothy I. Vonk, Jorien E. |
spellingShingle |
Jong, Dirk Bröder, Lisa Tesi, Tommaso Keskitalo, Kirsi H. Zimov, Nikita Davydova, Anna Pika, Philip Haghipour, Negar Eglinton, Timothy I. Vonk, Jorien E. Contrasts in dissolved, particulate and sedimentary organic carbon from the Kolyma River to the East Siberian Shelf |
author_facet |
Jong, Dirk Bröder, Lisa Tesi, Tommaso Keskitalo, Kirsi H. Zimov, Nikita Davydova, Anna Pika, Philip Haghipour, Negar Eglinton, Timothy I. Vonk, Jorien E. |
author_sort |
Jong, Dirk |
title |
Contrasts in dissolved, particulate and sedimentary organic carbon from the Kolyma River to the East Siberian Shelf |
title_short |
Contrasts in dissolved, particulate and sedimentary organic carbon from the Kolyma River to the East Siberian Shelf |
title_full |
Contrasts in dissolved, particulate and sedimentary organic carbon from the Kolyma River to the East Siberian Shelf |
title_fullStr |
Contrasts in dissolved, particulate and sedimentary organic carbon from the Kolyma River to the East Siberian Shelf |
title_full_unstemmed |
Contrasts in dissolved, particulate and sedimentary organic carbon from the Kolyma River to the East Siberian Shelf |
title_sort |
contrasts in dissolved, particulate and sedimentary organic carbon from the kolyma river to the east siberian shelf |
publisher |
Copernicus |
publishDate |
2022 |
url |
https://hdl.handle.net/20.500.11850/593091 https://doi.org/10.3929/ethz-b-000593091 |
long_lat |
ENVELOPE(161.000,161.000,69.500,69.500) ENVELOPE(166.000,166.000,74.000,74.000) ENVELOPE(-162.267,-162.267,74.400,74.400) |
geographic |
Arctic Kolyma East Siberian Sea East Siberian Shelf |
geographic_facet |
Arctic Kolyma East Siberian Sea East Siberian Shelf |
genre |
Arctic East Siberian Sea kolyma river permafrost |
genre_facet |
Arctic East Siberian Sea kolyma river permafrost |
op_source |
EGUsphere |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.5194/egusphere-2022-516 http://hdl.handle.net/20.500.11850/593091 doi:10.3929/ethz-b-000593091 |
op_rights |
info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/4.0/ Creative Commons Attribution 4.0 International |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/20.500.11850/593091 https://doi.org/10.3929/ethz-b-000593091 https://doi.org/10.5194/egusphere-2022-516 |
_version_ |
1766333898682269696 |