Publication Date:
2019-07-17
Description:
The valve area of Fragilariopsis kerguelensis, the most abundant diatom species in the
Southern Ocean, strongly changes in size in response to varying conditions in the surface
ocean. We examined the link, both in two iron fertilization experiments and in sediment
samples covering several glacial Terminations, between size variability in this species
and environmental conditions across the Antarctic Polar Front, including sea ice extent,
sea surface temperature, and the input of eolian dust. The iron fertilization experiments
show valve area to be positively correlated with iron concentrations in ambient waters,
which suggests the possibility of a causal relation between valve size of Fragilariopsis
kerguelensis and ambient surface water iron concentration. Larger valves are usually found
during glacial times and thus seem to be related to lower sea surface temperature and wider
sea ice coverage. Moreover, our results indicate that there usually is a strong correlation
between larger valve size and increased input of eolian dust to the Southern Ocean.
However, this correlation, obvious for the fertilization experiments and for glacial
Terminations I, II, III, and V, does not seem to be valid for Termination VI, where size
appears to be inversely correlated to dust input.
Repository Name:
EPIC Alfred Wegener Institut
Type:
Article
,
isiRev
Format:
application/pdf
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