The impact of land-fast ice on the distribution of terrestrial dissolved organic matter in the Siberian Arctic shelf seas
Remobilization of soil carbon as a result of permafrost degradation in the drainage basin of the major Siberian rivers combined with higher precipitation in a warming climate potentially increase the flux of terrestrial derived dissolved organic matter (tDOM) into the Arctic Ocean. The Laptev (LS) a...
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2021
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ftoceanrep:oai:oceanrep.geomar.de:51524 2023-05-15T14:27:01+02:00 The impact of land-fast ice on the distribution of terrestrial dissolved organic matter in the Siberian Arctic shelf seas Hölemann, Jens A. Juhls, Bennet Bauch, Dorothea Janout, Markus Koch, Boris P. Heim, Birgit 2021-01-05 text http://oceanrep.geomar.de/51524/ http://oceanrep.geomar.de/51524/1/bg-2020-462.pdf https://doi.org/10.5194/bg-2020-462 unknown Copernicus Publications (EGU) http://oceanrep.geomar.de/51524/1/bg-2020-462.pdf doi:10.5194/bg-2020-462 Hölemann, J. A., Juhls, B., Bauch, D. , Janout, M., Koch, B. P. and Heim, B. (Submitted) The impact of land-fast ice on the distribution of terrestrial dissolved organic matter in the Siberian Arctic shelf seas. Open Access Biogeosciences (BG) . DOI 10.5194/bg-2020-462 <http://dx.doi.org/10.5194/bg-2020-462>. info:eu-repo/semantics/openAccess (Submitted) Biogeosciences (BG) . Article PeerReviewed 2021 ftoceanrep https://doi.org/10.5194/bg-2020-462 2021-07-11T23:04:44Z Remobilization of soil carbon as a result of permafrost degradation in the drainage basin of the major Siberian rivers combined with higher precipitation in a warming climate potentially increase the flux of terrestrial derived dissolved organic matter (tDOM) into the Arctic Ocean. The Laptev (LS) and East Siberian Seas (ESS) receive enormous amounts of tDOM-rich river water, which undergoes at least one freeze-melt cycle in the Siberian Arctic shelf seas. To better understand how freezing and melting affect the tDOM dynamics in the LS and ESS, we sampled sea ice, river and seawater for their dissolved organic carbon (DOC) concentration and the colored fraction of dissolved organic matter. The sampling took place in different seasons over a period of 9 years (2010–2019). Our results suggest that the main factor regulating the tDOM distribution in the LS and ESS is the mixing of marine waters with freshwater sources carrying different tDOM concentrations. Of particular importance in this context are the 211 km3 of meltwater from land-fast ice from the LS, containing ~ 0.3 Tg DOC, which in spring mixes with 245 km3 of river water from the peak spring discharge of the Lena River, carrying ~ 2.4 Tg DOC into the LS. During the ice-free season, tDOM transport on the shelves takes place in the surface mixed layer, with the direction of transport depending on the prevailing wind direction. In winter, about 1.2 Tg of brine-related DOC, which was expelled from the growing land-fast ice in the LS, is transported in the near-surface water layer into the Transpolar Drift Stream that flows from the Siberian Shelf toward Greenland. The actual water depth in which the tDOM-rich brines are transported, depends mainly on the density stratification of the LS and ESS in the preceding summer and the amount of ice produced in winter. We suspect that climate change in the Arctic will fundamentally alter the dynamics of tDOM transport in the Arctic marginal seas, which will also have consequences for the Arctic carbon cycle. Article in Journal/Newspaper Arctic Arctic Arctic Ocean Climate change Greenland Ice laptev lena river permafrost Sea ice OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Arctic Arctic Ocean Greenland |
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Open Polar |
collection |
OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
op_collection_id |
ftoceanrep |
language |
unknown |
description |
Remobilization of soil carbon as a result of permafrost degradation in the drainage basin of the major Siberian rivers combined with higher precipitation in a warming climate potentially increase the flux of terrestrial derived dissolved organic matter (tDOM) into the Arctic Ocean. The Laptev (LS) and East Siberian Seas (ESS) receive enormous amounts of tDOM-rich river water, which undergoes at least one freeze-melt cycle in the Siberian Arctic shelf seas. To better understand how freezing and melting affect the tDOM dynamics in the LS and ESS, we sampled sea ice, river and seawater for their dissolved organic carbon (DOC) concentration and the colored fraction of dissolved organic matter. The sampling took place in different seasons over a period of 9 years (2010–2019). Our results suggest that the main factor regulating the tDOM distribution in the LS and ESS is the mixing of marine waters with freshwater sources carrying different tDOM concentrations. Of particular importance in this context are the 211 km3 of meltwater from land-fast ice from the LS, containing ~ 0.3 Tg DOC, which in spring mixes with 245 km3 of river water from the peak spring discharge of the Lena River, carrying ~ 2.4 Tg DOC into the LS. During the ice-free season, tDOM transport on the shelves takes place in the surface mixed layer, with the direction of transport depending on the prevailing wind direction. In winter, about 1.2 Tg of brine-related DOC, which was expelled from the growing land-fast ice in the LS, is transported in the near-surface water layer into the Transpolar Drift Stream that flows from the Siberian Shelf toward Greenland. The actual water depth in which the tDOM-rich brines are transported, depends mainly on the density stratification of the LS and ESS in the preceding summer and the amount of ice produced in winter. We suspect that climate change in the Arctic will fundamentally alter the dynamics of tDOM transport in the Arctic marginal seas, which will also have consequences for the Arctic carbon cycle. |
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 land-fast ice on the distribution of terrestrial dissolved organic matter in the Siberian Arctic shelf seas |
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 land-fast ice on the distribution of terrestrial dissolved organic matter in the Siberian Arctic shelf seas |
title_short |
The impact of land-fast ice on the distribution of terrestrial dissolved organic matter in the Siberian Arctic shelf seas |
title_full |
The impact of land-fast ice on the distribution of terrestrial dissolved organic matter in the Siberian Arctic shelf seas |
title_fullStr |
The impact of land-fast ice on the distribution of terrestrial dissolved organic matter in the Siberian Arctic shelf seas |
title_full_unstemmed |
The impact of land-fast ice on the distribution of terrestrial dissolved organic matter in the Siberian Arctic shelf seas |
title_sort |
impact of land-fast ice on the distribution of terrestrial dissolved organic matter in the siberian arctic shelf seas |
publisher |
Copernicus Publications (EGU) |
publishDate |
2021 |
url |
http://oceanrep.geomar.de/51524/ http://oceanrep.geomar.de/51524/1/bg-2020-462.pdf https://doi.org/10.5194/bg-2020-462 |
geographic |
Arctic Arctic Ocean Greenland |
geographic_facet |
Arctic Arctic Ocean Greenland |
genre |
Arctic Arctic Arctic Ocean Climate change Greenland Ice laptev lena river permafrost Sea ice |
genre_facet |
Arctic Arctic Arctic Ocean Climate change Greenland Ice laptev lena river permafrost Sea ice |
op_source |
(Submitted) Biogeosciences (BG) . |
op_relation |
http://oceanrep.geomar.de/51524/1/bg-2020-462.pdf doi:10.5194/bg-2020-462 Hölemann, J. A., Juhls, B., Bauch, D. , Janout, M., Koch, B. P. and Heim, B. (Submitted) The impact of land-fast ice on the distribution of terrestrial dissolved organic matter in the Siberian Arctic shelf seas. Open Access Biogeosciences (BG) . DOI 10.5194/bg-2020-462 <http://dx.doi.org/10.5194/bg-2020-462>. |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.5194/bg-2020-462 |
_version_ |
1766300572267315200 |