Pathways of Siberian Freshwater and Sea Ice in the Arctic Ocean Traced with Radiogenic Neodymium Isotopes and Rare Earth Elements
Abstract: Freshwater and sea ice in the Arctic Ocean (AO) both respond to climate forcing but changes in their distribution may in turn also significantly affect Northern Hemisphere climate. The exact mechanisms controlling their transport are, however, still subject of ongoing research. Radiogenic...
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Alfred-Wegener-Institut für Polar- und Meeresforschung und Deutsche Gesellschaft für Polarforschung
2017
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Online Access: | https://dx.doi.org/10.2312/polarforschung.87.1.3 https://www.tib.eu/suchen/id/awi:1313014b1bda06ccbfd3818223b6dfc24802697e |
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ftdatacite:10.2312/polarforschung.87.1.3 2023-05-15T14:58:15+02:00 Pathways of Siberian Freshwater and Sea Ice in the Arctic Ocean Traced with Radiogenic Neodymium Isotopes and Rare Earth Elements Laukert, Georgi Frank, Martin Hathorne, Ed C Krumpen, Thomas Rabe, Ben Bauch, Dorothea Werner, Kirstin Peeken, Ilka Kassens, Heidemarie 2017 application/pdf https://dx.doi.org/10.2312/polarforschung.87.1.3 https://www.tib.eu/suchen/id/awi:1313014b1bda06ccbfd3818223b6dfc24802697e en eng Alfred-Wegener-Institut für Polar- und Meeresforschung und Deutsche Gesellschaft für Polarforschung Alfred-Wegener-Institut für Polar- und Meeresforschung und Deutsche Gesellschaft für Polarforschung Earth Science Earth sciences and geology article-journal Electronic Resource ScholarlyArticle JournalArticle 2017 ftdatacite https://doi.org/10.2312/polarforschung.87.1.3 2022-04-01T17:57:47Z Abstract: Freshwater and sea ice in the Arctic Ocean (AO) both respond to climate forcing but changes in their distribution may in turn also significantly affect Northern Hemisphere climate. The exact mechanisms controlling their transport are, however, still subject of ongoing research. Radiogenic neodymium (Nd) isotopes (expressed as εNd) and rare earth elements (REEs) have successfully been used to trace ocean circulation in the AO and can provide valuable information on the origin, transport and fate of Arctic freshwater and drifting sea ice. Here, we present first sea-ice data and discuss the applicability of these tracers to determine the pathways of Siberian freshwater and the source areas of Arctic sea ice within the Eurasian Basin. Freshwaters originating from various Siberian rivers are well mixed and diluted prior to their advection to the central AO and the Fram Strait, thereby inhibiting the assessment of the individual contributions of the different rivers for these regions. Recent investigations of seawater Nd isotope and REE distributions on the Siberian shelves now allow for a more detailed determination of the sources of transpolar freshwater transport, and suggest that freshwater from the Lena River can at least be qualitatively traced further away from the shelves. In addition, sea ice has the potential to preserve marine and riverine εNd and REE signatures of the Siberian shelf source waters transported across the AO to the Fram Strait thereby avoiding the effects of mixing. Here, we test this potential for the first time by comparing εNd and REE signatures determined from unfiltered but essentially sediment-free sea-ice samples recovered in the Eurasian Basin of the central AO in 2012 with corresponding signatures of surface seawater in the formation regions of the ice. The sampled sea ice is dominantly characterized by εNd values near -8, in agreement with the incorporation of radiogenic freshwater (εNd = -6) from the Yenisei and Ob rivers and its formation east of Vilkitsky Strait as identified by a backtracking approach based on satellite-derived ice drift and concentration data. The latter also indicates that sea ice with a less radiogenic εNd signature near -11 formed north of the Laptev Sea, in agreement with mixed contributions of radiogenic waters from the Kara Sea and northward flowing highly unradiogenic Lena River water (εNd ≤ -15). Compared to the REE concentrations in Siberian shelf waters, those in the sea ice are depleted, indicating rejection of REEs together with salt during sea-ice formation. Despite potential modifications during incorporation into sea ice, its REE distribution patterns indicate a predictable relationship to those of the source waters, thus in addition supporting preservation of at least some of the marine and riverine REE characteristics during sea-ice formation and transport. : Polarforschung Article in Journal/Newspaper Arctic Arctic Ocean Fram Strait Kara Sea laptev Laptev Sea lena river Sea ice DataCite Metadata Store (German National Library of Science and Technology) Arctic Arctic Ocean Kara Sea Laptev Sea |
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Open Polar |
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DataCite Metadata Store (German National Library of Science and Technology) |
op_collection_id |
ftdatacite |
language |
English |
topic |
Earth Science Earth sciences and geology |
spellingShingle |
Earth Science Earth sciences and geology Laukert, Georgi Frank, Martin Hathorne, Ed C Krumpen, Thomas Rabe, Ben Bauch, Dorothea Werner, Kirstin Peeken, Ilka Kassens, Heidemarie Pathways of Siberian Freshwater and Sea Ice in the Arctic Ocean Traced with Radiogenic Neodymium Isotopes and Rare Earth Elements |
topic_facet |
Earth Science Earth sciences and geology |
description |
Abstract: Freshwater and sea ice in the Arctic Ocean (AO) both respond to climate forcing but changes in their distribution may in turn also significantly affect Northern Hemisphere climate. The exact mechanisms controlling their transport are, however, still subject of ongoing research. Radiogenic neodymium (Nd) isotopes (expressed as εNd) and rare earth elements (REEs) have successfully been used to trace ocean circulation in the AO and can provide valuable information on the origin, transport and fate of Arctic freshwater and drifting sea ice. Here, we present first sea-ice data and discuss the applicability of these tracers to determine the pathways of Siberian freshwater and the source areas of Arctic sea ice within the Eurasian Basin. Freshwaters originating from various Siberian rivers are well mixed and diluted prior to their advection to the central AO and the Fram Strait, thereby inhibiting the assessment of the individual contributions of the different rivers for these regions. Recent investigations of seawater Nd isotope and REE distributions on the Siberian shelves now allow for a more detailed determination of the sources of transpolar freshwater transport, and suggest that freshwater from the Lena River can at least be qualitatively traced further away from the shelves. In addition, sea ice has the potential to preserve marine and riverine εNd and REE signatures of the Siberian shelf source waters transported across the AO to the Fram Strait thereby avoiding the effects of mixing. Here, we test this potential for the first time by comparing εNd and REE signatures determined from unfiltered but essentially sediment-free sea-ice samples recovered in the Eurasian Basin of the central AO in 2012 with corresponding signatures of surface seawater in the formation regions of the ice. The sampled sea ice is dominantly characterized by εNd values near -8, in agreement with the incorporation of radiogenic freshwater (εNd = -6) from the Yenisei and Ob rivers and its formation east of Vilkitsky Strait as identified by a backtracking approach based on satellite-derived ice drift and concentration data. The latter also indicates that sea ice with a less radiogenic εNd signature near -11 formed north of the Laptev Sea, in agreement with mixed contributions of radiogenic waters from the Kara Sea and northward flowing highly unradiogenic Lena River water (εNd ≤ -15). Compared to the REE concentrations in Siberian shelf waters, those in the sea ice are depleted, indicating rejection of REEs together with salt during sea-ice formation. Despite potential modifications during incorporation into sea ice, its REE distribution patterns indicate a predictable relationship to those of the source waters, thus in addition supporting preservation of at least some of the marine and riverine REE characteristics during sea-ice formation and transport. : Polarforschung |
format |
Article in Journal/Newspaper |
author |
Laukert, Georgi Frank, Martin Hathorne, Ed C Krumpen, Thomas Rabe, Ben Bauch, Dorothea Werner, Kirstin Peeken, Ilka Kassens, Heidemarie |
author_facet |
Laukert, Georgi Frank, Martin Hathorne, Ed C Krumpen, Thomas Rabe, Ben Bauch, Dorothea Werner, Kirstin Peeken, Ilka Kassens, Heidemarie |
author_sort |
Laukert, Georgi |
title |
Pathways of Siberian Freshwater and Sea Ice in the Arctic Ocean Traced with Radiogenic Neodymium Isotopes and Rare Earth Elements |
title_short |
Pathways of Siberian Freshwater and Sea Ice in the Arctic Ocean Traced with Radiogenic Neodymium Isotopes and Rare Earth Elements |
title_full |
Pathways of Siberian Freshwater and Sea Ice in the Arctic Ocean Traced with Radiogenic Neodymium Isotopes and Rare Earth Elements |
title_fullStr |
Pathways of Siberian Freshwater and Sea Ice in the Arctic Ocean Traced with Radiogenic Neodymium Isotopes and Rare Earth Elements |
title_full_unstemmed |
Pathways of Siberian Freshwater and Sea Ice in the Arctic Ocean Traced with Radiogenic Neodymium Isotopes and Rare Earth Elements |
title_sort |
pathways of siberian freshwater and sea ice in the arctic ocean traced with radiogenic neodymium isotopes and rare earth elements |
publisher |
Alfred-Wegener-Institut für Polar- und Meeresforschung und Deutsche Gesellschaft für Polarforschung |
publishDate |
2017 |
url |
https://dx.doi.org/10.2312/polarforschung.87.1.3 https://www.tib.eu/suchen/id/awi:1313014b1bda06ccbfd3818223b6dfc24802697e |
geographic |
Arctic Arctic Ocean Kara Sea Laptev Sea |
geographic_facet |
Arctic Arctic Ocean Kara Sea Laptev Sea |
genre |
Arctic Arctic Ocean Fram Strait Kara Sea laptev Laptev Sea lena river Sea ice |
genre_facet |
Arctic Arctic Ocean Fram Strait Kara Sea laptev Laptev Sea lena river Sea ice |
op_rights |
Alfred-Wegener-Institut für Polar- und Meeresforschung und Deutsche Gesellschaft für Polarforschung |
op_doi |
https://doi.org/10.2312/polarforschung.87.1.3 |
_version_ |
1766330339791208448 |