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Enhanced iron flux to Antarctic sea ice via dust deposition from ice-free coastal areas

Citation

Duprat, L and Kanna, N and Janssens, J and Roukaerts, A and Deman, F and Townsend, AT and Meiners, KM and van der Merwe, P and Lannuzel, D, Enhanced iron flux to Antarctic sea ice via dust deposition from ice-free coastal areas, Journal of Geophysical Research: Oceans, 124, (12) pp. 8538-8557. ISSN 2169-9275 (2019) [Refereed Article]


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DOI: doi:10.1029/2019JC015221

Abstract

Antarctic sea ice is an important temporal reservoir of iron which can boost primary production in the marginal ice zone during the seasonal melt. While studies have reported that Antarctic fast ice bears high concentrations of iron due to the proximity to coastal sources, less clear are the biogeochemical changes this iron pool undergoes during late spring. Here we describe a 3‐week time series of physical and biogeochemical data, including iron, from first‐year coastal fast ice sampled near Davis Station (Prydz Bay, East Antarctica) during late austral spring 2015. Our study shows that dissolved and particulate iron concentrations in sea ice were up to two orders of magnitude higher than in under‐ice seawater. Furthermore, our results indicate a significant contribution of lithogenic iron from the Vestfold Hills (as deduced from the comparison with crustal element ratios) to the particulate iron pool in fast ice after a blizzard event halfway through the time series. Windblown dust represented approximately 75% of the particulate iron found in the ice and is a potential candidate for keeping concentrations of soluble iron stable during our observations. These results suggest that iron entrapped during ice formation, likely from sediments, as well as local input of coastal dust, supports primary productivity in Davis fast ice. As ice‐free land areas are likely to expand over the course of the century, this work highlights the need to quantify iron inputs from continental Antarctic dust and its bioavailability for ice algae and phytoplankton.

Item Details

Item Type:Refereed Article
Keywords:sea ice, fast ice, Fe, dust, phytoplankton, algae
Research Division:Chemical Sciences
Research Group:Other Chemical Sciences
Research Field:Environmental Chemistry (incl. Atmospheric Chemistry)
Objective Division:Environment
Objective Group:Climate and Climate Change
Objective Field:Effects of Climate Change and Variability on Antarctic and Sub-Antarctic Environments (excl. Social Impacts)
UTAS Author:Duprat, L (Mr Duprat)
UTAS Author:Janssens, J (Miss Julie Janssens)
UTAS Author:Townsend, AT (Associate Professor Ashley Townsend)
UTAS Author:Meiners, KM (Dr Klaus Meiners)
UTAS Author:van der Merwe, P (Dr Pier van der Merwe)
UTAS Author:Lannuzel, D (Associate Professor Delphine Lannuzel)
ID Code:136209
Year Published:2019
Deposited By:Oceans and Cryosphere
Deposited On:2019-12-06
Last Modified:2020-01-29
Downloads:0

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