Organic ligands control the concentrations of dissolved iron in Antarctic sea ice
The organic complexation of iron (Fe) was assessed in 5 snow, 34 sea ice, 12 brine and 24 under-ice seawater samples collected during a time series in the East Antarctic sector in austral summer 2009. Similar to seawater, over 99% of Fe was bound to organic ligands in snow, sea ice and brines throug...
Main Authors: | , , , |
---|---|
Format: | Conference Object |
Language: | English |
Published: |
-
2015
|
Subjects: | |
Online Access: | http://ecite.utas.edu.au/104062 |
id |
ftunivtasecite:oai:ecite.utas.edu.au:104062 |
---|---|
record_format |
openpolar |
spelling |
ftunivtasecite:oai:ecite.utas.edu.au:104062 2023-05-15T14:03:25+02:00 Organic ligands control the concentrations of dissolved iron in Antarctic sea ice Lannuzel, D Grotti, M Abelmoschi, ML Van Der Merwe, P 2015 application/msword http://ecite.utas.edu.au/104062 en eng - http://ecite.utas.edu.au/104062/1/Lannuzel et al. Goldschmidt.doc http://purl.org/au-research/grants/arc/DE120100030 Lannuzel, D and Grotti, M and Abelmoschi, ML and Van Der Merwe, P, Organic ligands control the concentrations of dissolved iron in Antarctic sea ice, Goldschmidt2015 Abstracts, 16-21 August, Prague, Czech Republic, pp. 1766. (2015) [Conference Extract] http://ecite.utas.edu.au/104062 Earth Sciences Oceanography Chemical Oceanography Conference Extract NonPeerReviewed 2015 ftunivtasecite 2019-12-13T22:05:26Z The organic complexation of iron (Fe) was assessed in 5 snow, 34 sea ice, 12 brine and 24 under-ice seawater samples collected during a time series in the East Antarctic sector in austral summer 2009. Similar to seawater, over 99% of Fe was bound to organic ligands in snow, sea ice and brines throughout the study. Dissolved organic ligand and Fe concentrations were higher in the brines and sea ice than in snow and seawater samples. In sea ice, [DFe] ranged from 2.1 to 81.0 nM and organic Fe complexing ligands ([Lt]) ranged from 4.5 to 72.1 nM, with complex stability logKFeL = 21.0-23.0. Estimated concentrations of inorganic Fe ([Fe]) in sea ice ranged from 0.1 to 98.2 pM. In brines, [DFe] ranged from 0.3 to 34.6 nM and [Lt] ranged from 5.9 to 41.4 nM, with complex stability logKFeL=21.0-22.0. Estimated concentrations of inorganic Fe (Fe) in brines ranged from 0.7 to 7.2 pM. Organic ligands were nearly saturated with Fe in both sea ice and brines, with positive linear relationships observed between [DFe] and [Lt]: [Lt] = 0.90 [DFe] + 4.24 (R2 = 0.93, n = 34) in sea ice and [Lt] = 1.08[DFe] + 4.86 (R2 = 0.98, n = 12) in brines. Our results therefore suggest that the organic ligands produced by sea ice algae and bacteria keep Fe in the dissolved phase therefore enhancing its availability for the sea ice algal community. When DFe concentrations become higher than the ligand concentrations, non-organically bound Fe is transferred into the particulate phase by scavenging, biological uptake or precipitation processes. As sea ice starts to melt, DFe will be released into seawater together with organic ligands, potentially increasing the residence time of Fe in Antarctic surface waters and its bio-availability for the phytoplankton community. Conference Object Antarc* Antarctic ice algae Sea ice eCite UTAS (University of Tasmania) Antarctic Austral |
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 Lannuzel, D Grotti, M Abelmoschi, ML Van Der Merwe, P Organic ligands control the concentrations of dissolved iron in Antarctic sea ice |
topic_facet |
Earth Sciences Oceanography Chemical Oceanography |
description |
The organic complexation of iron (Fe) was assessed in 5 snow, 34 sea ice, 12 brine and 24 under-ice seawater samples collected during a time series in the East Antarctic sector in austral summer 2009. Similar to seawater, over 99% of Fe was bound to organic ligands in snow, sea ice and brines throughout the study. Dissolved organic ligand and Fe concentrations were higher in the brines and sea ice than in snow and seawater samples. In sea ice, [DFe] ranged from 2.1 to 81.0 nM and organic Fe complexing ligands ([Lt]) ranged from 4.5 to 72.1 nM, with complex stability logKFeL = 21.0-23.0. Estimated concentrations of inorganic Fe ([Fe]) in sea ice ranged from 0.1 to 98.2 pM. In brines, [DFe] ranged from 0.3 to 34.6 nM and [Lt] ranged from 5.9 to 41.4 nM, with complex stability logKFeL=21.0-22.0. Estimated concentrations of inorganic Fe (Fe) in brines ranged from 0.7 to 7.2 pM. Organic ligands were nearly saturated with Fe in both sea ice and brines, with positive linear relationships observed between [DFe] and [Lt]: [Lt] = 0.90 [DFe] + 4.24 (R2 = 0.93, n = 34) in sea ice and [Lt] = 1.08[DFe] + 4.86 (R2 = 0.98, n = 12) in brines. Our results therefore suggest that the organic ligands produced by sea ice algae and bacteria keep Fe in the dissolved phase therefore enhancing its availability for the sea ice algal community. When DFe concentrations become higher than the ligand concentrations, non-organically bound Fe is transferred into the particulate phase by scavenging, biological uptake or precipitation processes. As sea ice starts to melt, DFe will be released into seawater together with organic ligands, potentially increasing the residence time of Fe in Antarctic surface waters and its bio-availability for the phytoplankton community. |
format |
Conference Object |
author |
Lannuzel, D Grotti, M Abelmoschi, ML Van Der Merwe, P |
author_facet |
Lannuzel, D Grotti, M Abelmoschi, ML Van Der Merwe, P |
author_sort |
Lannuzel, D |
title |
Organic ligands control the concentrations of dissolved iron in Antarctic sea ice |
title_short |
Organic ligands control the concentrations of dissolved iron in Antarctic sea ice |
title_full |
Organic ligands control the concentrations of dissolved iron in Antarctic sea ice |
title_fullStr |
Organic ligands control the concentrations of dissolved iron in Antarctic sea ice |
title_full_unstemmed |
Organic ligands control the concentrations of dissolved iron in Antarctic sea ice |
title_sort |
organic ligands control the concentrations of dissolved iron in antarctic sea ice |
publisher |
- |
publishDate |
2015 |
url |
http://ecite.utas.edu.au/104062 |
geographic |
Antarctic Austral |
geographic_facet |
Antarctic Austral |
genre |
Antarc* Antarctic ice algae Sea ice |
genre_facet |
Antarc* Antarctic ice algae Sea ice |
op_relation |
http://ecite.utas.edu.au/104062/1/Lannuzel et al. Goldschmidt.doc http://purl.org/au-research/grants/arc/DE120100030 Lannuzel, D and Grotti, M and Abelmoschi, ML and Van Der Merwe, P, Organic ligands control the concentrations of dissolved iron in Antarctic sea ice, Goldschmidt2015 Abstracts, 16-21 August, Prague, Czech Republic, pp. 1766. (2015) [Conference Extract] http://ecite.utas.edu.au/104062 |
_version_ |
1766274073419055104 |