Influence of organic complexation on dissolved iron distribution in East Antarctic pack ice
Since Antarctic sea ice covers an area larger than the Antarctic continent itself, the discovery that it can fertilize the Southern Ocean with iron (Fe) has fostered a new breadth of research in recent years. In order to test the hypothesis that Fe-binding organic ligands control the distribution of...
Published in: | Marine Chemistry |
---|---|
Main Authors: | , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Elsevier Science Bv
2018
|
Subjects: | |
Online Access: | https://doi.org/10.1016/j.marchem.2018.04.005 http://ecite.utas.edu.au/126077 |
id |
ftunivtasecite:oai:ecite.utas.edu.au:126077 |
---|---|
record_format |
openpolar |
spelling |
ftunivtasecite:oai:ecite.utas.edu.au:126077 2023-05-15T13:55:18+02:00 Influence of organic complexation on dissolved iron distribution in East Antarctic pack ice Genovese, C Grotti, M Pittaluga, J Ardini, F Janssens, J Wuttig, K Moreau, S Lannuzel, D 2018 https://doi.org/10.1016/j.marchem.2018.04.005 http://ecite.utas.edu.au/126077 en eng Elsevier Science Bv http://dx.doi.org/10.1016/j.marchem.2018.04.005 Genovese, C and Grotti, M and Pittaluga, J and Ardini, F and Janssens, J and Wuttig, K and Moreau, S and Lannuzel, D, Influence of organic complexation on dissolved iron distribution in East Antarctic pack ice, Marine Chemistry, 203 pp. 28-37. ISSN 0304-4203 (2018) [Refereed Article] http://ecite.utas.edu.au/126077 Earth Sciences Oceanography Chemical Oceanography Refereed Article PeerReviewed 2018 ftunivtasecite https://doi.org/10.1016/j.marchem.2018.04.005 2019-12-13T22:24:32Z Since Antarctic sea ice covers an area larger than the Antarctic continent itself, the discovery that it can fertilize the Southern Ocean with iron (Fe) has fostered a new breadth of research in recent years. In order to test the hypothesis that Fe-binding organic ligands control the distribution of dissolved iron (DFe) in Antarctic pack ice, iron organic speciation was investigated in samples collected during the Sea Ice Physics and Ecosystem eXperiment-2 (SIPEX-2) voyage in Austral winter/spring 2012. Dissolved Fe was measured using sector field inductively coupled plasma mass spectrometry, and iron organic speciation parameters were determined by competitive ligand equilibration - adsorptive cathodic stripping voltammetry method, using 1-nitroso-2-naphthol (NN) as the added ligand. The concentration of Fe-binding organic ligands (Lt) ranged from 4.9 nM to 41 nM (average of 14.9 8.4 nM, n = 34), and was always higher than the corresponding DFe (average of 7.5 4.5 nM, n = 34). Conditional stability constants (log K′ FeL = 11.713.0) were similar to those previously observed in land-fast ice. Concentrations of DFe and Lt displayed similar depth profiles; their strong correlation (Spearman's ρ = 0.80, p < 0.001) suggested that Fe-binding organic ligands control DFe distribution in Antarctic pack ice. Unlike results previously obtained for land-fast ice, Fe-binding organic ligands in pack ice were never saturated with iron (Lt/DFe > 1). Estimates showed that pack ice would have released 0.45 μmol/m 2 /d of Lt during spring melt, 0.21 μmol/m 2 /d of which are free from Fe binding, and hence available for further complexation. Therefore, it is suggested that this excess of Fe-free ligands may play a key role in controlling the solubility of free or newly formed Fe in surface waters before the peak of primary production, outcompeting the Fe-binding organic ligands already present in seawater. Article in Journal/Newspaper Antarc* Antarctic Sea ice Southern Ocean eCite UTAS (University of Tasmania) Antarctic Austral Southern Ocean The Antarctic Marine Chemistry 203 28 37 |
institution |
Open Polar |
collection |
eCite UTAS (University of Tasmania) |
op_collection_id |
ftunivtasecite |
language |
English |
topic |
Earth Sciences Oceanography Chemical Oceanography |
spellingShingle |
Earth Sciences Oceanography Chemical Oceanography Genovese, C Grotti, M Pittaluga, J Ardini, F Janssens, J Wuttig, K Moreau, S Lannuzel, D Influence of organic complexation on dissolved iron distribution in East Antarctic pack ice |
topic_facet |
Earth Sciences Oceanography Chemical Oceanography |
description |
Since Antarctic sea ice covers an area larger than the Antarctic continent itself, the discovery that it can fertilize the Southern Ocean with iron (Fe) has fostered a new breadth of research in recent years. In order to test the hypothesis that Fe-binding organic ligands control the distribution of dissolved iron (DFe) in Antarctic pack ice, iron organic speciation was investigated in samples collected during the Sea Ice Physics and Ecosystem eXperiment-2 (SIPEX-2) voyage in Austral winter/spring 2012. Dissolved Fe was measured using sector field inductively coupled plasma mass spectrometry, and iron organic speciation parameters were determined by competitive ligand equilibration - adsorptive cathodic stripping voltammetry method, using 1-nitroso-2-naphthol (NN) as the added ligand. The concentration of Fe-binding organic ligands (Lt) ranged from 4.9 nM to 41 nM (average of 14.9 8.4 nM, n = 34), and was always higher than the corresponding DFe (average of 7.5 4.5 nM, n = 34). Conditional stability constants (log K′ FeL = 11.713.0) were similar to those previously observed in land-fast ice. Concentrations of DFe and Lt displayed similar depth profiles; their strong correlation (Spearman's ρ = 0.80, p < 0.001) suggested that Fe-binding organic ligands control DFe distribution in Antarctic pack ice. Unlike results previously obtained for land-fast ice, Fe-binding organic ligands in pack ice were never saturated with iron (Lt/DFe > 1). Estimates showed that pack ice would have released 0.45 μmol/m 2 /d of Lt during spring melt, 0.21 μmol/m 2 /d of which are free from Fe binding, and hence available for further complexation. Therefore, it is suggested that this excess of Fe-free ligands may play a key role in controlling the solubility of free or newly formed Fe in surface waters before the peak of primary production, outcompeting the Fe-binding organic ligands already present in seawater. |
format |
Article in Journal/Newspaper |
author |
Genovese, C Grotti, M Pittaluga, J Ardini, F Janssens, J Wuttig, K Moreau, S Lannuzel, D |
author_facet |
Genovese, C Grotti, M Pittaluga, J Ardini, F Janssens, J Wuttig, K Moreau, S Lannuzel, D |
author_sort |
Genovese, C |
title |
Influence of organic complexation on dissolved iron distribution in East Antarctic pack ice |
title_short |
Influence of organic complexation on dissolved iron distribution in East Antarctic pack ice |
title_full |
Influence of organic complexation on dissolved iron distribution in East Antarctic pack ice |
title_fullStr |
Influence of organic complexation on dissolved iron distribution in East Antarctic pack ice |
title_full_unstemmed |
Influence of organic complexation on dissolved iron distribution in East Antarctic pack ice |
title_sort |
influence of organic complexation on dissolved iron distribution in east antarctic pack ice |
publisher |
Elsevier Science Bv |
publishDate |
2018 |
url |
https://doi.org/10.1016/j.marchem.2018.04.005 http://ecite.utas.edu.au/126077 |
geographic |
Antarctic Austral Southern Ocean The Antarctic |
geographic_facet |
Antarctic Austral Southern Ocean The Antarctic |
genre |
Antarc* Antarctic Sea ice Southern Ocean |
genre_facet |
Antarc* Antarctic Sea ice Southern Ocean |
op_relation |
http://dx.doi.org/10.1016/j.marchem.2018.04.005 Genovese, C and Grotti, M and Pittaluga, J and Ardini, F and Janssens, J and Wuttig, K and Moreau, S and Lannuzel, D, Influence of organic complexation on dissolved iron distribution in East Antarctic pack ice, Marine Chemistry, 203 pp. 28-37. ISSN 0304-4203 (2018) [Refereed Article] http://ecite.utas.edu.au/126077 |
op_doi |
https://doi.org/10.1016/j.marchem.2018.04.005 |
container_title |
Marine Chemistry |
container_volume |
203 |
container_start_page |
28 |
op_container_end_page |
37 |
_version_ |
1766261676743589888 |