The Stability of Fe-Isotope Signatures During Low Salinity Mixing in Subarctic Estuaries
We have studied iron (Fe)-isotope signals in particles (> 0.22 µm) and the dissolved phase (< 0.22 µm) in two subarctic, boreal rivers, their estuaries and the adjacent sea in northern Sweden. Both rivers, the Råne and the Kalix, are enriched in Fe and organic carbon (up to 29 µmol/L and up to...
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Online Access: | https://oceanrep.geomar.de/id/eprint/48480/ https://oceanrep.geomar.de/id/eprint/48480/1/Conrad2019_Article_TheStabilityOfFe-IsotopeSignat.pdf https://doi.org/10.1007/s10498-019-09360-z |
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ftoceanrep:oai:oceanrep.geomar.de:48480 2023-05-15T17:44:50+02:00 The Stability of Fe-Isotope Signatures During Low Salinity Mixing in Subarctic Estuaries Conrad, Sarah Wuttig, Kathrin Jansen, Nils Rodushkin, Ilia Ingri, Johan 2019-12 text https://oceanrep.geomar.de/id/eprint/48480/ https://oceanrep.geomar.de/id/eprint/48480/1/Conrad2019_Article_TheStabilityOfFe-IsotopeSignat.pdf https://doi.org/10.1007/s10498-019-09360-z en eng Springer https://oceanrep.geomar.de/id/eprint/48480/1/Conrad2019_Article_TheStabilityOfFe-IsotopeSignat.pdf Conrad, S. , Wuttig, K. , Jansen, N., Rodushkin, I. and Ingri, J. (2019) The Stability of Fe-Isotope Signatures During Low Salinity Mixing in Subarctic Estuaries. Open Access Aquatic Geochemistry, 25 (5-6). pp. 195-218. DOI 10.1007/s10498-019-09360-z <https://doi.org/10.1007/s10498-019-09360-z>. doi:10.1007/s10498-019-09360-z cc_by_4.0 info:eu-repo/semantics/openAccess Article PeerReviewed 2019 ftoceanrep https://doi.org/10.1007/s10498-019-09360-z 2023-04-07T15:48:36Z We have studied iron (Fe)-isotope signals in particles (> 0.22 µm) and the dissolved phase (< 0.22 µm) in two subarctic, boreal rivers, their estuaries and the adjacent sea in northern Sweden. Both rivers, the Råne and the Kalix, are enriched in Fe and organic carbon (up to 29 µmol/L and up to 730 µmol/L, respectively). Observed changes in the particulate and dissolved phase during spring flood in May suggest different sources of Fe to the rivers during different seasons. While particles show a positive Fe-isotope signal during winter, during spring flood, the values are negative. Increased discharge due to snowmelt in the boreal region is most times accompanied by flushing of the organic-rich sub-surface layers. These upper podzol soil layers have been shown to be a source for Fe-organic carbon aggregates with a negative Fe-isotope signal. During winter, the rivers are mostly fed by deep groundwater, where Fe occurs as Fe(oxy)hydroxides, with a positive Fe-isotope signal. Flocculation during initial estuarine mixing does not change the Fe-isotope compositions of the two phases. Data indicate that the two groups of Fe aggregates flocculate diversely in the estuaries due to differences in their surface structure. Within the open sea, the particulate phase showed heavier δ56Fe values than in the estuaries. Our data indicate the flocculation of the negative Fe-isotope signal in a low salinity environment, due to changes in the ionic strength and further the increase of pH. Article in Journal/Newspaper Northern Sweden Subarctic OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Kalix ENVELOPE(23.156,23.156,65.853,65.853) Aquatic Geochemistry 25 5-6 195 218 |
institution |
Open Polar |
collection |
OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
op_collection_id |
ftoceanrep |
language |
English |
description |
We have studied iron (Fe)-isotope signals in particles (> 0.22 µm) and the dissolved phase (< 0.22 µm) in two subarctic, boreal rivers, their estuaries and the adjacent sea in northern Sweden. Both rivers, the Råne and the Kalix, are enriched in Fe and organic carbon (up to 29 µmol/L and up to 730 µmol/L, respectively). Observed changes in the particulate and dissolved phase during spring flood in May suggest different sources of Fe to the rivers during different seasons. While particles show a positive Fe-isotope signal during winter, during spring flood, the values are negative. Increased discharge due to snowmelt in the boreal region is most times accompanied by flushing of the organic-rich sub-surface layers. These upper podzol soil layers have been shown to be a source for Fe-organic carbon aggregates with a negative Fe-isotope signal. During winter, the rivers are mostly fed by deep groundwater, where Fe occurs as Fe(oxy)hydroxides, with a positive Fe-isotope signal. Flocculation during initial estuarine mixing does not change the Fe-isotope compositions of the two phases. Data indicate that the two groups of Fe aggregates flocculate diversely in the estuaries due to differences in their surface structure. Within the open sea, the particulate phase showed heavier δ56Fe values than in the estuaries. Our data indicate the flocculation of the negative Fe-isotope signal in a low salinity environment, due to changes in the ionic strength and further the increase of pH. |
format |
Article in Journal/Newspaper |
author |
Conrad, Sarah Wuttig, Kathrin Jansen, Nils Rodushkin, Ilia Ingri, Johan |
spellingShingle |
Conrad, Sarah Wuttig, Kathrin Jansen, Nils Rodushkin, Ilia Ingri, Johan The Stability of Fe-Isotope Signatures During Low Salinity Mixing in Subarctic Estuaries |
author_facet |
Conrad, Sarah Wuttig, Kathrin Jansen, Nils Rodushkin, Ilia Ingri, Johan |
author_sort |
Conrad, Sarah |
title |
The Stability of Fe-Isotope Signatures During Low Salinity Mixing in Subarctic Estuaries |
title_short |
The Stability of Fe-Isotope Signatures During Low Salinity Mixing in Subarctic Estuaries |
title_full |
The Stability of Fe-Isotope Signatures During Low Salinity Mixing in Subarctic Estuaries |
title_fullStr |
The Stability of Fe-Isotope Signatures During Low Salinity Mixing in Subarctic Estuaries |
title_full_unstemmed |
The Stability of Fe-Isotope Signatures During Low Salinity Mixing in Subarctic Estuaries |
title_sort |
stability of fe-isotope signatures during low salinity mixing in subarctic estuaries |
publisher |
Springer |
publishDate |
2019 |
url |
https://oceanrep.geomar.de/id/eprint/48480/ https://oceanrep.geomar.de/id/eprint/48480/1/Conrad2019_Article_TheStabilityOfFe-IsotopeSignat.pdf https://doi.org/10.1007/s10498-019-09360-z |
long_lat |
ENVELOPE(23.156,23.156,65.853,65.853) |
geographic |
Kalix |
geographic_facet |
Kalix |
genre |
Northern Sweden Subarctic |
genre_facet |
Northern Sweden Subarctic |
op_relation |
https://oceanrep.geomar.de/id/eprint/48480/1/Conrad2019_Article_TheStabilityOfFe-IsotopeSignat.pdf Conrad, S. , Wuttig, K. , Jansen, N., Rodushkin, I. and Ingri, J. (2019) The Stability of Fe-Isotope Signatures During Low Salinity Mixing in Subarctic Estuaries. Open Access Aquatic Geochemistry, 25 (5-6). pp. 195-218. DOI 10.1007/s10498-019-09360-z <https://doi.org/10.1007/s10498-019-09360-z>. doi:10.1007/s10498-019-09360-z |
op_rights |
cc_by_4.0 info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1007/s10498-019-09360-z |
container_title |
Aquatic Geochemistry |
container_volume |
25 |
container_issue |
5-6 |
container_start_page |
195 |
op_container_end_page |
218 |
_version_ |
1766147131472609280 |