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| Titel |
Vorticity and potential vorticity analysis for viscous bottom flow along the Sicily Channel (central Mediterranean Sea) |
| VerfasserIn |
Federico Falcini, Ettore Salusti |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250091636
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| Publikation (Nr.) |
 EGU/EGU2014-5937.pdf |
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| Zusammenfassung |
| A dense water vein, i.e., the Eastern Mediterranean Deep Water (EMDW), which flows
westward along the bottom of the Sicily Channel (Mediterranean Sea)shows an unexpected
cross-channel tilting of the deep water interface around the main sill of the Channel. From
cross-stream averages of the EMDW thickness and velocity, we here discuss a new diagnostic
model for vertical vorticity (ζ) and potential vorticity (Π) of this deep flow, and its
cross-stream profile properties. Our model takes into account friction and mixing, which are
important features for current crossing marine straits. We find that, approaching the main
sill of the Sicily Channel, the current vorticity decreases because of sea bottom
topography and friction, reaching large negative values over the Channel main sill.
Downstream of the sill, the vorticity of the vein increases again reaching usual values.
We demonstrate that friction tends to decrease Πas long as ζ is positive but, once
ζgecomes negative, the corresponding Πhas a remarkable increase due to strong
bottom friction in the sill region. These diagnoses on ζ and Πfor deep flow allow
one to gain general insights on the stability, path and cross-sectional structure of
deep currents flowing along straits, as well as on some morphodynamic features
that may result from the interaction between the bottom current and the seafloor. |
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