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Titel |
Interaction of a monopole vortex with an isolated topographic feature in a three-layer geophysical flow |
VerfasserIn |
E. A. Ryzhov, K. V. Koshel |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1023-5809
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Digitales Dokument |
URL |
Erschienen |
In: Nonlinear Processes in Geophysics ; 20, no. 1 ; Nr. 20, no. 1 (2013-02-14), S.107-119 |
Datensatznummer |
250017733
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Publikation (Nr.) |
copernicus.org/npg-20-107-2013.pdf |
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Zusammenfassung |
In the frame of a three-layer, quasi-geostrophic analytical model of an
f-plane geophysical flow, the Lagrangian advection induced by the
interaction of a monopole vortex with an isolated topographic feature is
addressed. Two different cases when the monopole is located either within the
upper or the middle layer are of our interest. In the bottom layer, there is
a delta-function topographic feature, which generates a closed recirculation
region in its vicinity due to the background flow. This recirculation region
extends to the middle and upper layers, and it plays the role of a
topographic vortex. The interaction between the monopole and the topographic
vortex causes a complex, including chaotic, advection of fluid particles. We
show that the model's parameters, namely the monopole and topographic
vortices' strengths and initial positions, and the layers' depths and
densities, are responsible for the diverse advection patterns. While the patterns are
rather complicated, one can single out two major processes, which
mostly govern the fluid particle advection. The first one is the variation in
time of the system's phase space structure, so that within the closed region
of the topographic vortex, there appear periodically unclosed particle
pathways by which the particles leave the topographic vortex. The second one
is chaotic advection that arises from the nonstationarity of the
monopole–topography interaction. |
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