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| Titel |
Natural iron enrichment around the Antarctic Peninsula in the Southern Ocean |
| VerfasserIn |
M. V. Ardelan, O. Holm-Hansen, C. D. Hewes, C. S. Reiss, N. S. Silva, H. Dulaiova, E. Steinnes, E. Sakshaug |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 7, no. 1 ; Nr. 7, no. 1 (2010-01-05), S.11-25 |
| Datensatznummer |
250004361
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| Publikation (Nr.) |
 copernicus.org/bg-7-11-2010.pdf |
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| Zusammenfassung |
| As part of the US-AMLR program in January-February of 2006, 99 stations in
the South Shetland Islands-Antarctic Peninsula region were sampled to
understand the variability in hydrographic and biological properties related
to the abundance and distribution of krill in this area. Concentrations of
dissolved iron (DFe) and total acid-leachable iron (TaLFe) were measured in
the upper 150 m at 16 of these stations (both coastal and pelagic waters) to
better resolve the factors limiting primary production in this area and in
downstream waters of the Scotia Sea. The concentrations of DFe and TaLFe in
the upper mixed layer (UML) were relatively high in Weddell Sea Shelf Waters
(~0.6 nM and 15 nM, respectively) and low in Drake Passage waters
(~0.2 nM and 0.9 nM, respectively). In the Bransfield
Strait, representing a mixture of waters from the Weddell Sea and the
Antarctic Circumpolar Current (ACC), concentrations of DFe were ~0.4 nM
and of TaLFe ~1.7 nM. The highest concentrations of DFe and TaLFe
in the UML were found at shallow coastal stations close to Livingston Island
(~1.6 nM and 100 nM, respectively). The ratio of TaLFe:DFe varied
with the distance to land: ~45 at the shallow coastal stations, ~15
in the high-salinity waters of Bransfield Strait, and ~4 in ACC
waters. Concentrations of DFe increased slightly with depth in the water
column, while that of TaLFe did not show any consistent trend with depth.
Our Fe data are discussed in regard to the hydrography and water circulation
patterns in the study area, and with the hypothesis that the relatively high
rates of primary production in the central regions of the Scotia Sea are
partially sustained by natural iron enrichment resulting
from a northeasterly flow of iron-rich coastal waters originating in
the South Shetland Islands-Antarctic Peninsula region. |
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