Distribution of Fe isotopes in particles and colloids in the salinity gradient along the Lena River plume, Laptev Sea
Riverine Fe input is the primary Fe source for the ocean. This study is focused on the distribution of Fe along the Lena River freshwater plume in the Laptev Sea using samples from a 600 km long transect in front of the Lena River mouth. Separation of the particulate ( >0.22 µ m), colloidal (0.22...
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ftcopernicus:oai:publications.copernicus.org:bg67820 2023-05-15T15:00:29+02:00 Distribution of Fe isotopes in particles and colloids in the salinity gradient along the Lena River plume, Laptev Sea Conrad, Sarah Ingri, Johan Gelting, Johan Nordblad, Fredrik Engström, Emma Rodushkin, Ilia Andersson, Per S. Porcelli, Don Gustafsson, Örjan Semiletov, Igor Öhlander, Björn 2019-03-28 application/pdf https://doi.org/10.5194/bg-16-1305-2019 https://www.biogeosciences.net/16/1305/2019/ eng eng doi:10.5194/bg-16-1305-2019 https://www.biogeosciences.net/16/1305/2019/ eISSN: 1726-4189 Text 2019 ftcopernicus https://doi.org/10.5194/bg-16-1305-2019 2019-12-24T09:49:21Z Riverine Fe input is the primary Fe source for the ocean. This study is focused on the distribution of Fe along the Lena River freshwater plume in the Laptev Sea using samples from a 600 km long transect in front of the Lena River mouth. Separation of the particulate ( >0.22 µ m), colloidal (0.22 µ m–1 kDa), and truly dissolved ( <1 kDa) fractions of Fe was carried out. The total Fe concentrations ranged from 0.2 to 57 µ M with Fe dominantly as particulate Fe. The loss of >99 % of particulate Fe and about 90 % of the colloidal Fe was observed across the shelf, while the truly dissolved phase was almost constant across the Laptev Sea. Thus, the truly dissolved Fe could be an important source of bioavailable Fe for plankton in the central Arctic Ocean, together with the colloidal Fe. Fe-isotope analysis showed that the particulate phase and the sediment below the Lena River freshwater plume had negative δ 56 Fe values (relative to IRMM-14). The colloidal Fe phase showed negative δ 56 Fe values close to the river mouth (about −0.20 ‰) and positive δ 56 Fe values in the outermost stations (about +0.10 ‰). We suggest that the shelf zone acts as a sink for Fe particles and colloids with negative δ 56 Fe values, representing chemically reactive ferrihydrites. The positive δ 56 Fe values of the colloidal phase within the outer Lena River freshwater plume might represent Fe oxyhydroxides, which remain in the water column, and will be the predominant δ 56 Fe composition in the Arctic Ocean. Text Arctic Arctic Ocean laptev Laptev Sea lena river Copernicus Publications: E-Journals Arctic Arctic Ocean Laptev Sea Biogeosciences 16 6 1305 1319 |
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Open Polar |
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Copernicus Publications: E-Journals |
op_collection_id |
ftcopernicus |
language |
English |
description |
Riverine Fe input is the primary Fe source for the ocean. This study is focused on the distribution of Fe along the Lena River freshwater plume in the Laptev Sea using samples from a 600 km long transect in front of the Lena River mouth. Separation of the particulate ( >0.22 µ m), colloidal (0.22 µ m–1 kDa), and truly dissolved ( <1 kDa) fractions of Fe was carried out. The total Fe concentrations ranged from 0.2 to 57 µ M with Fe dominantly as particulate Fe. The loss of >99 % of particulate Fe and about 90 % of the colloidal Fe was observed across the shelf, while the truly dissolved phase was almost constant across the Laptev Sea. Thus, the truly dissolved Fe could be an important source of bioavailable Fe for plankton in the central Arctic Ocean, together with the colloidal Fe. Fe-isotope analysis showed that the particulate phase and the sediment below the Lena River freshwater plume had negative δ 56 Fe values (relative to IRMM-14). The colloidal Fe phase showed negative δ 56 Fe values close to the river mouth (about −0.20 ‰) and positive δ 56 Fe values in the outermost stations (about +0.10 ‰). We suggest that the shelf zone acts as a sink for Fe particles and colloids with negative δ 56 Fe values, representing chemically reactive ferrihydrites. The positive δ 56 Fe values of the colloidal phase within the outer Lena River freshwater plume might represent Fe oxyhydroxides, which remain in the water column, and will be the predominant δ 56 Fe composition in the Arctic Ocean. |
format |
Text |
author |
Conrad, Sarah Ingri, Johan Gelting, Johan Nordblad, Fredrik Engström, Emma Rodushkin, Ilia Andersson, Per S. Porcelli, Don Gustafsson, Örjan Semiletov, Igor Öhlander, Björn |
spellingShingle |
Conrad, Sarah Ingri, Johan Gelting, Johan Nordblad, Fredrik Engström, Emma Rodushkin, Ilia Andersson, Per S. Porcelli, Don Gustafsson, Örjan Semiletov, Igor Öhlander, Björn Distribution of Fe isotopes in particles and colloids in the salinity gradient along the Lena River plume, Laptev Sea |
author_facet |
Conrad, Sarah Ingri, Johan Gelting, Johan Nordblad, Fredrik Engström, Emma Rodushkin, Ilia Andersson, Per S. Porcelli, Don Gustafsson, Örjan Semiletov, Igor Öhlander, Björn |
author_sort |
Conrad, Sarah |
title |
Distribution of Fe isotopes in particles and colloids in the salinity gradient along the Lena River plume, Laptev Sea |
title_short |
Distribution of Fe isotopes in particles and colloids in the salinity gradient along the Lena River plume, Laptev Sea |
title_full |
Distribution of Fe isotopes in particles and colloids in the salinity gradient along the Lena River plume, Laptev Sea |
title_fullStr |
Distribution of Fe isotopes in particles and colloids in the salinity gradient along the Lena River plume, Laptev Sea |
title_full_unstemmed |
Distribution of Fe isotopes in particles and colloids in the salinity gradient along the Lena River plume, Laptev Sea |
title_sort |
distribution of fe isotopes in particles and colloids in the salinity gradient along the lena river plume, laptev sea |
publishDate |
2019 |
url |
https://doi.org/10.5194/bg-16-1305-2019 https://www.biogeosciences.net/16/1305/2019/ |
geographic |
Arctic Arctic Ocean Laptev Sea |
geographic_facet |
Arctic Arctic Ocean Laptev Sea |
genre |
Arctic Arctic Ocean laptev Laptev Sea lena river |
genre_facet |
Arctic Arctic Ocean laptev Laptev Sea lena river |
op_source |
eISSN: 1726-4189 |
op_relation |
doi:10.5194/bg-16-1305-2019 https://www.biogeosciences.net/16/1305/2019/ |
op_doi |
https://doi.org/10.5194/bg-16-1305-2019 |
container_title |
Biogeosciences |
container_volume |
16 |
container_issue |
6 |
container_start_page |
1305 |
op_container_end_page |
1319 |
_version_ |
1766332578182201344 |