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Titel |
Low-frequency variability in idealised GCM experiments with circumpolar and localised storm tracks |
VerfasserIn |
W. Müller, R. Blender, K. Fraedrich |
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 ; 9, no. 1 ; Nr. 9, no. 1, S.37-49 |
Datensatznummer |
250006598
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Publikation (Nr.) |
copernicus.org/npg-9-37-2002.pdf |
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Zusammenfassung |
Idealised global
circulation model simulations with circumpolar and localised (one and two)
storm tracks are re-analysed to determine scaling, intermittency and
phase-space structures. In a hundred year experiment with a circumpolar
storm track, the spectrum S(f ) of the first principal component of
the zonal wind fluctuations shows the following power law regimes: (a) a
short-term memory between f- -4 and f -2
up to 50 days and (b) a long-term memory f -1 from 50 to
400 days and f -0.24 beyond 400 days, similar to
observed maritime single station near-surface air temperature data. In the
presence of localised storm tracks, the wave number two dominates the
dynamics and a long-term memory cannot be detected. The recurrence plot is
introduced as a novel tool to comprehensively visualise the evolution of
the dynamical system in terms of state separations (distances) in phase
space. The patterns allow for a qualitative interpretation of the
underlying local phenomena in phase space, such as waves, analogs,
extremes, and global regimes. Attractor dimensions are, in general, larger
than 10, but they appear to be lower in the wave-dominated regimes of the
double storm track experiment. |
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