The impact of the freeze–melt cycle of land-fast ice on the distribution of dissolved organic matter in the Laptev and East Siberian seas (Siberian Arctic)
Permafrost degradation in the catchment of major Siberian rivers, combined with higher precipitation in a warming climate, could increase the flux of terrestrially derived dissolved organic matter (tDOM) into the Arctic Ocean (AO). Each year, ∼ 7.9 Tg of dissolved organic carbon (DOC) is discharged...
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Copernicus Publications (EGU)
2021
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Online Access: | https://oceanrep.geomar.de/id/eprint/52901/ https://oceanrep.geomar.de/id/eprint/52901/1/bg-18-3637-2021.pdf https://doi.org/10.5194/bg-18-3637-2021 |
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ftoceanrep:oai:oceanrep.geomar.de:52901 2024-02-11T09:59:40+01:00 The impact of the freeze–melt cycle of land-fast ice on the distribution of dissolved organic matter in the Laptev and East Siberian seas (Siberian Arctic) Hölemann, Jens A. Juhls, Bennet Bauch, Dorothea Janout, Markus Koch, Boris P. Heim, Birgit 2021-06-18 text https://oceanrep.geomar.de/id/eprint/52901/ https://oceanrep.geomar.de/id/eprint/52901/1/bg-18-3637-2021.pdf https://doi.org/10.5194/bg-18-3637-2021 en eng Copernicus Publications (EGU) https://oceanrep.geomar.de/id/eprint/52901/1/bg-18-3637-2021.pdf Hölemann, J. A., Juhls, B., Bauch, D. , Janout, M., Koch, B. P. and Heim, B. (2021) The impact of the freeze–melt cycle of land-fast ice on the distribution of dissolved organic matter in the Laptev and East Siberian seas (Siberian Arctic). Open Access Biogeosciences (BG), 18 (12). pp. 3637-3655. DOI 10.5194/bg-18-3637-2021 <https://doi.org/10.5194/bg-18-3637-2021>. doi:10.5194/bg-18-3637-2021 cc_by_4.0 info:eu-repo/semantics/openAccess Article PeerReviewed 2021 ftoceanrep https://doi.org/10.5194/bg-18-3637-2021 2024-01-15T00:23:45Z Permafrost degradation in the catchment of major Siberian rivers, combined with higher precipitation in a warming climate, could increase the flux of terrestrially derived dissolved organic matter (tDOM) into the Arctic Ocean (AO). Each year, ∼ 7.9 Tg of dissolved organic carbon (DOC) is discharged into the AO via the three largest rivers that flow into the Laptev Sea (LS) and East Siberian Sea (ESS). A significant proportion of this tDOM-rich river water undergoes at least one freeze–melt cycle in the land-fast ice that forms along the coast of the Laptev and East Siberian seas in winter. To better understand how growth and melting of land-fast ice affect dissolved organic matter (DOM) dynamics in the LS and ESS, we determined DOC concentrations and the optical properties of coloured dissolved organic matter (CDOM) in sea ice, river water and seawater. The data set, covering different seasons over a 9-year period (2010–2019), was complemented by oceanographic measurements (T, S) and determination of the oxygen isotope composition of the seawater. Although removal of tDOM cannot be ruled out, our study suggests that conservative mixing of high-tDOM river water and sea-ice meltwater with low-tDOM seawater is the major factor controlling the surface distribution of tDOM in the LS and ESS. A case study based on data from winter 2012 and spring 2014 reveals that the mixing of about 273 km3 of low-tDOM land-fast-ice meltwater (containing ∼ 0.3 Tg DOC) with more than 200 km3 of high-tDOM Lena River water discharged during the spring freshet (∼ 2.8 Tg DOC yr−1) plays a dominant role in this respect. The mixing of the two low-salinity surface water masses is possible because the meltwater and the river water of the spring freshet flow into the southeastern LS at the same time every year (May–July). In addition, budget calculations indicate that in the course of the growth of land-fast ice in the southeastern LS, ∼ 1.2 Tg DOC yr−1 (± 0.54 Tg) can be expelled from the growing ice in winter, together with brines. These ... Article in Journal/Newspaper Arctic Arctic Arctic Ocean East Siberian Sea Ice laptev Laptev Sea lena river permafrost Sea ice OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Arctic Arctic Ocean East Siberian Sea ENVELOPE(166.000,166.000,74.000,74.000) Laptev Sea Biogeosciences 18 12 3637 3655 |
institution |
Open Polar |
collection |
OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
op_collection_id |
ftoceanrep |
language |
English |
description |
Permafrost degradation in the catchment of major Siberian rivers, combined with higher precipitation in a warming climate, could increase the flux of terrestrially derived dissolved organic matter (tDOM) into the Arctic Ocean (AO). Each year, ∼ 7.9 Tg of dissolved organic carbon (DOC) is discharged into the AO via the three largest rivers that flow into the Laptev Sea (LS) and East Siberian Sea (ESS). A significant proportion of this tDOM-rich river water undergoes at least one freeze–melt cycle in the land-fast ice that forms along the coast of the Laptev and East Siberian seas in winter. To better understand how growth and melting of land-fast ice affect dissolved organic matter (DOM) dynamics in the LS and ESS, we determined DOC concentrations and the optical properties of coloured dissolved organic matter (CDOM) in sea ice, river water and seawater. The data set, covering different seasons over a 9-year period (2010–2019), was complemented by oceanographic measurements (T, S) and determination of the oxygen isotope composition of the seawater. Although removal of tDOM cannot be ruled out, our study suggests that conservative mixing of high-tDOM river water and sea-ice meltwater with low-tDOM seawater is the major factor controlling the surface distribution of tDOM in the LS and ESS. A case study based on data from winter 2012 and spring 2014 reveals that the mixing of about 273 km3 of low-tDOM land-fast-ice meltwater (containing ∼ 0.3 Tg DOC) with more than 200 km3 of high-tDOM Lena River water discharged during the spring freshet (∼ 2.8 Tg DOC yr−1) plays a dominant role in this respect. The mixing of the two low-salinity surface water masses is possible because the meltwater and the river water of the spring freshet flow into the southeastern LS at the same time every year (May–July). In addition, budget calculations indicate that in the course of the growth of land-fast ice in the southeastern LS, ∼ 1.2 Tg DOC yr−1 (± 0.54 Tg) can be expelled from the growing ice in winter, together with brines. These ... |
format |
Article in Journal/Newspaper |
author |
Hölemann, Jens A. Juhls, Bennet Bauch, Dorothea Janout, Markus Koch, Boris P. Heim, Birgit |
spellingShingle |
Hölemann, Jens A. Juhls, Bennet Bauch, Dorothea Janout, Markus Koch, Boris P. Heim, Birgit The impact of the freeze–melt cycle of land-fast ice on the distribution of dissolved organic matter in the Laptev and East Siberian seas (Siberian Arctic) |
author_facet |
Hölemann, Jens A. Juhls, Bennet Bauch, Dorothea Janout, Markus Koch, Boris P. Heim, Birgit |
author_sort |
Hölemann, Jens A. |
title |
The impact of the freeze–melt cycle of land-fast ice on the distribution of dissolved organic matter in the Laptev and East Siberian seas (Siberian Arctic) |
title_short |
The impact of the freeze–melt cycle of land-fast ice on the distribution of dissolved organic matter in the Laptev and East Siberian seas (Siberian Arctic) |
title_full |
The impact of the freeze–melt cycle of land-fast ice on the distribution of dissolved organic matter in the Laptev and East Siberian seas (Siberian Arctic) |
title_fullStr |
The impact of the freeze–melt cycle of land-fast ice on the distribution of dissolved organic matter in the Laptev and East Siberian seas (Siberian Arctic) |
title_full_unstemmed |
The impact of the freeze–melt cycle of land-fast ice on the distribution of dissolved organic matter in the Laptev and East Siberian seas (Siberian Arctic) |
title_sort |
impact of the freeze–melt cycle of land-fast ice on the distribution of dissolved organic matter in the laptev and east siberian seas (siberian arctic) |
publisher |
Copernicus Publications (EGU) |
publishDate |
2021 |
url |
https://oceanrep.geomar.de/id/eprint/52901/ https://oceanrep.geomar.de/id/eprint/52901/1/bg-18-3637-2021.pdf https://doi.org/10.5194/bg-18-3637-2021 |
long_lat |
ENVELOPE(166.000,166.000,74.000,74.000) |
geographic |
Arctic Arctic Ocean East Siberian Sea Laptev Sea |
geographic_facet |
Arctic Arctic Ocean East Siberian Sea Laptev Sea |
genre |
Arctic Arctic Arctic Ocean East Siberian Sea Ice laptev Laptev Sea lena river permafrost Sea ice |
genre_facet |
Arctic Arctic Arctic Ocean East Siberian Sea Ice laptev Laptev Sea lena river permafrost Sea ice |
op_relation |
https://oceanrep.geomar.de/id/eprint/52901/1/bg-18-3637-2021.pdf Hölemann, J. A., Juhls, B., Bauch, D. , Janout, M., Koch, B. P. and Heim, B. (2021) The impact of the freeze–melt cycle of land-fast ice on the distribution of dissolved organic matter in the Laptev and East Siberian seas (Siberian Arctic). Open Access Biogeosciences (BG), 18 (12). pp. 3637-3655. DOI 10.5194/bg-18-3637-2021 <https://doi.org/10.5194/bg-18-3637-2021>. doi:10.5194/bg-18-3637-2021 |
op_rights |
cc_by_4.0 info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.5194/bg-18-3637-2021 |
container_title |
Biogeosciences |
container_volume |
18 |
container_issue |
12 |
container_start_page |
3637 |
op_container_end_page |
3655 |
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1790595466812981248 |