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High temporal resolution observations of spring fast ice melt and seawater iron enrichment in East Antarctica
Citation
Van Der Merwe, P and Lannuzel, D and Bowie, AR and Meiners, K, High temporal resolution observations of spring fast ice melt and seawater iron enrichment in East Antarctica, Journal of Geophysical Research-Space Physics, 116 Article G03017. ISSN 0148-0227 (2011) [Refereed Article]
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Copyright Statement
Copyright 2011 by the American Geophysical Union.
Abstract
A time series experiment was conducted in late austral spring
(November–December 2009) in coastal fast ice, East Antarctica (66°13!07"S,
110°39!02"E). Iron (Fe) measurements were made in sea ice, snow, brines,
and underlying seawater, together with meteorological, physical, and biogeochemical
measurements to investigate the processes controlling the release of Fe into the
underlying water column. Warming air temperatures were clearly associated with
decreasing brine volume fractions. Macronutrient profiles revealed very low
(<1 mM) nitrate + nitrite concentrations in the interior of the sea ice, and the brines
suggested nitrate + nitrite drawdown exceeded Redfield ratios in comparison to
phosphate and silicate. In the basal ice, nitrate + nitrite and silicate were drawn down
through time but did not lead to a limiting condition. We found that dissolved Fe tracked
the brine volume fraction and was readily transferred from the surface/interior to the
underlying water column over time. In contrast, particulate Fe did not show this clear
decreasing trend and correlated with particulate organic carbon and chlorophyll a
distributions. Over the 28 d of sampling, two distinct mean air temperature warming events
were observed (−12.1 to −1.3°C and −6.4 to 0.8°C). This resulted in the release of
419 mmol of TDFe per m2 of sea ice from our coastal fast ice station into the underlying
water column during the study period. Assuming an increase of 1 nM Fe is sufficient
for Antarctic diatoms to bloom, our study site presented a fertilization potential for
419 m3 of Fe limited surface Southern Ocean seawater with TDFe and 29 m3 with dFe,
per m2 of fast ice.
Item Details
| Item Type: | Refereed Article |
|---|---|
| Research Division: | Environmental Sciences |
| Research Group: | Ecological Applications |
| Research Field: | Ecosystem Function |
| 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: | Van Der Merwe, P (Dr Pier van der Merwe) |
| UTAS Author: | Lannuzel, D (Associate Professor Delphine Lannuzel) |
| UTAS Author: | Bowie, AR (Associate Professor Andrew Bowie) |
| UTAS Author: | Meiners, K (Dr Klaus Meiners) |
| ID Code: | 72246 |
| Year Published: | 2011 |
| Web of Science® Times Cited: | 32 |
| Deposited By: | IMAS Research and Education Centre |
| Deposited On: | 2011-08-24 |
| Last Modified: | 2018-03-30 |
| Downloads: | 0 |
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