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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ftcopernicus:oai:publications.copernicus.org:egusphere104691 2023-05-15T15:14:38+02:00 Contrasts in dissolved, particulate and sedimentary organic carbon from the Kolyma River to the East Siberian Shelf Jong, Dirk J. Bröder, Lisa Tesi, Tommaso Keskitalo, Kirsi H. Zimov, Nikita Davydova, Anna Pika, Philip Haghipour, Negar Eglinton, Timothy I. Vonk, Jorien E. 2023-01-17 application/pdf https://doi.org/10.5194/egusphere-2022-516 https://egusphere.copernicus.org/preprints/2022/egusphere-2022-516/ eng eng doi:10.5194/egusphere-2022-516 https://egusphere.copernicus.org/preprints/2022/egusphere-2022-516/ eISSN: Text 2023 ftcopernicus https://doi.org/10.5194/egusphere-2022-516 2023-01-23T17:22:43Z 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 focus 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). They were compared with earlier findings in marine sediments. Carbon isotopes ( δ 13 C , Δ 14 C ), lignin phenol, and lipid biomarker proxies show a contrasting composition and degradation state of these different carbon pools. Dual C 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 %), whereas 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 might be relatively degraded, regardless of its generally young age shown by previous studies. In contrast, SOC shows the lowest Δ 14 C value (oldest OC), yet relatively fresh compositional signatures. Furthermore, decreasing mineral surface area-normalised OC- and biomarker loadings suggest that SOC might be reactive along the land–ocean continuum and almost all parameters were subjected to rapid change when moving from freshwater to the marine environment. This suggests that sedimentary dynamics play a crucial role when targeting permafrost-derived OC in aquatic systems and ... Text Arctic East Siberian Sea kolyma river permafrost Copernicus Publications: E-Journals Arctic East Siberian Sea ENVELOPE(166.000,166.000,74.000,74.000) East Siberian Shelf ENVELOPE(-162.267,-162.267,74.400,74.400) Kolyma ENVELOPE(161.000,161.000,69.500,69.500) |
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Open Polar |
collection |
Copernicus Publications: E-Journals |
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ftcopernicus |
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 focus 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). They were compared with earlier findings in marine sediments. Carbon isotopes ( δ 13 C , Δ 14 C ), lignin phenol, and lipid biomarker proxies show a contrasting composition and degradation state of these different carbon pools. Dual C 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 %), whereas 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 might be relatively degraded, regardless of its generally young age shown by previous studies. In contrast, SOC shows the lowest Δ 14 C value (oldest OC), yet relatively fresh compositional signatures. Furthermore, decreasing mineral surface area-normalised OC- and biomarker loadings suggest that SOC might be reactive along the land–ocean continuum and almost all parameters were subjected to rapid change when moving from freshwater to the marine environment. This suggests that sedimentary dynamics play a crucial role when targeting permafrost-derived OC in aquatic systems and ... |
format |
Text |
author |
Jong, Dirk J. Bröder, Lisa Tesi, Tommaso Keskitalo, Kirsi H. Zimov, Nikita Davydova, Anna Pika, Philip Haghipour, Negar Eglinton, Timothy I. Vonk, Jorien E. |
spellingShingle |
Jong, Dirk J. 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 J. 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 J. |
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 |
publishDate |
2023 |
url |
https://doi.org/10.5194/egusphere-2022-516 https://egusphere.copernicus.org/preprints/2022/egusphere-2022-516/ |
long_lat |
ENVELOPE(166.000,166.000,74.000,74.000) ENVELOPE(-162.267,-162.267,74.400,74.400) ENVELOPE(161.000,161.000,69.500,69.500) |
geographic |
Arctic East Siberian Sea East Siberian Shelf Kolyma |
geographic_facet |
Arctic East Siberian Sea East Siberian Shelf Kolyma |
genre |
Arctic East Siberian Sea kolyma river permafrost |
genre_facet |
Arctic East Siberian Sea kolyma river permafrost |
op_source |
eISSN: |
op_relation |
doi:10.5194/egusphere-2022-516 https://egusphere.copernicus.org/preprints/2022/egusphere-2022-516/ |
op_doi |
https://doi.org/10.5194/egusphere-2022-516 |
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1766345059325706240 |