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Titel |
Deep Western Boundary Current transport variability in the South Atlantic: preliminary results from a pilot array at 34.5° S |
VerfasserIn |
C. S. Meinen, A. R. Piola, R. C. Perez, S. L. Garzoli |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1812-0784
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Digitales Dokument |
URL |
Erschienen |
In: Ocean Science ; 8, no. 6 ; Nr. 8, no. 6 (2012-11-29), S.1041-1054 |
Datensatznummer |
250006016
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Publikation (Nr.) |
copernicus.org/os-8-1041-2012.pdf |
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Zusammenfassung |
The first direct estimates of the temporal variability of the absolute
transport in the Deep Western Boundary Current (DWBC) at 34.5° S in
the South Atlantic Ocean are obtained using just under one year of data from
a line of four pressure-equipped inverted echo sounders. Hydrographic
sections collected in 2009 and 2010 confirm, based on neutral density,
temperature, salinity, and oxygen values, the presence of the DWBC, one of
the main deep pathways of the Meridional Overturning Circulation. Both data
sets indicate that the DWBC reconstitutes itself after breaking into eddies
in the western sub-tropical Atlantic near 8° S. The amplitude and
spectral character of the DWBC transport variability are comparable with
those observed in the North Atlantic, where longer records exist, with the
DWBC at 34.5° S exhibiting a transport standard deviation of 25 Sv
and variations of ∼ 40 Sv occurring within periods as short as a few
days. There is little indication of an annual cycle in the DWBC transports,
although the observational records are too short to be definitive. A Monte
Carlo-style analysis using 27 yr of model output from the same location as
the observations indicates that about 48–60 months of data will be required
to fully assess the deep transport variability. The model suggests the
presence of an annual cycle in DWBC transport, however its statistical
significance with even 27 yr of model output is low, suggesting that
seasonal variations in the model are weak. |
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