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| Titel |
Diapycnal diffusivity at the upper boundary of the North Tropical Atlantic oxygen minimum zone |
| VerfasserIn |
D. Banyte, T. Tanhua, M. Visbeck, D. Wallace, J. Karstensen, G. Krahmann, A. Schneider, L. Stramma |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250059120
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| Zusammenfassung |
| Diapycnal mixing was studied in the tropical northeastern Atlantic by a deliberate tracer
release experiment in 2008 - 2010. The tracer, CF3SF5, was injected on an isopycnal surface
ÏăÎ = 26.88 kg m-3, which corresponds to about 350 m depth. Three surveys performed 7
months, 20 months and 30 months after the release, sampled the laterally and vertically
expanding tracer patch. The diapycnal diffusivity for the whole period was found to be
(1.2 ± 0.1) Ã 10-5 m2 s-1, or in density units (3.1 ± 0.2) Ã 10-11 (kg m-3)2 s-1. The
result expressed in density units is independent of stratification, which in the studied
region had a gradient increasing from 2.1 cph in the north-west to 2.7 cph in the
south-east. Correspondingly, the diapycnal diffusivity estimate expressed in depth
units was ranging from 0.7 to 1.3 Ã 10-5 m2 s-1. Diapycnal diffusivity studied in
density units revealed increased diapycnal mixing by about 30% over the seamount
region. |
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