 |
| Titel |
Antarctic ice sheet fertilises the Southern Ocean |
| VerfasserIn |
R. Death, J. L. Wadham, F. Monteiro, A. M. Le Brocq, M. Tranter, A. Ridgwell, S. Dutkiewicz, R. Raiswell |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1726-4170
|
| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 11, no. 10 ; Nr. 11, no. 10 (2014-05-19), S.2635-2643 |
| Datensatznummer |
250117414
|
| Publikation (Nr.) |
 copernicus.org/bg-11-2635-2014.pdf |
|
|
|
|
|
| Zusammenfassung |
| Southern Ocean (SO) marine primary productivity (PP) is strongly influenced
by the availability of iron in surface waters, which is thought to exert a
significant control upon atmospheric CO2 concentrations on
glacial/interglacial timescales. The zone bordering the Antarctic Ice Sheet
exhibits high PP and seasonal plankton blooms in response to light and
variations in iron availability. The sources of iron stimulating elevated SO
PP are in debate. Established contributors include dust, coastal
sediments/upwelling, icebergs and sea ice. Subglacial meltwater exported at
the ice margin is a more recent suggestion, arising from intense iron cycling
beneath the ice sheet. Icebergs and subglacial meltwater may supply a large
amount of bioavailable iron to the SO, estimated in this study at
0.07–0.2 Tg yr−1. Here we apply the MIT global ocean model (Follows
et al., 2007) to determine the potential impact of this level of iron export
from the ice sheet upon SO PP. The export of iron from the ice sheet raises
modelled SO PP by up to 40%, and provides one plausible explanation for seasonally
very high in situ measurements of PP in the near-coastal zone. The
impact on SO PP is greatest in coastal regions, which are also areas of high
measured marine PP. These results suggest that the export of Antarctic runoff
and icebergs may have an important impact on SO PP and should be included in
future biogeochemical modelling. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|