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Distribution of dissolved and particulate metals in Antarctic sea ice
journal contribution
posted on 2023-05-17, 10:34 authored by Delphine LannuzelDelphine Lannuzel, Andrew BowieAndrew Bowie, Pier van der MerwePier van der Merwe, Ashley TownsendAshley Townsend, Schoemann, VSamples were collected in East Antarctic sea ice in late winter/early austral spring 2007 to assess the distributions of Al, Cr, Mn, Cu, Zn, Mo, Cd and Ba. Total dissolved (b0.2 ìm) and particulate (N0.2 ìm) concentrations were measured by Inductively Coupled Plasma-Sector Field Mass Spectrometry (ICP-SFMS) in snow, pack ice and fast ice. Particulate concentrations were also determined in underlying seawater for these elements. The concentrations of particulate metals were one to two orders of magnitude higher in sea ice than in snow and seawater, except for Mo and Cr. Barite maxima in sea ice vertical profiles at all sites may indicate heterotrophic activity. Particulate Al and Mn distributions suggest a signal from Antarctica's shelf sediments. Dissolved metals were one order of magnitude higher in sea ice as compared to snow, although they were not enriched in sea ice as compared to data reported in the literature for Antarctic surface waters. An analysis of dissolved-to-total metal ratios showed that all studied metals were found almost exclusively in the dissolved phase in Antarctic pack ice. Dissolved metals distributions indicate that spatial variability does not seem to be strong. Our results also demonstrate that dissolved Al, Cr, Mo and Ba behaved conservatively with bulk ice salinity gradients. This would confirm the main source of trace metals to Antarctic sea ice comes from seawater and not from direct atmospheric deposition. Dissolved bioactive metals Mn, Cu, Zn and Cd concentrations were scattered when plotted against bulk ice salinity, but did not show a seasonal decrease nor reach limitation status. Finally, seasonal ice melt does not seem to contribute significantly to the supply of dissolved bioactive metals, other than Fe, to Antarctic surface waters.
Funding
Australian Research Council
History
Publication title
Marine Chemistry: An International Journal for Studies of All Chemical Aspects of The Marine EnvironmentVolume
124Issue
1-4Pagination
134-146ISSN
0304-4203Department/School
Institute for Marine and Antarctic StudiesPublisher
Elsevier Science BvPlace of publication
Po Box 211, Amsterdam, Netherlands, 1000 AeRights statement
The definitive version is available at http://www.sciencedirect.comRepository Status
- Restricted