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| Titel |
Multifractality and autoregressive processes of dry spell lengths in Europe: an approach to their complexity and predictability |
| VerfasserIn |
Maria-Dolors Martinez, Xavier Lana, Augusto Burgueño, Carina Serra |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250102444
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| Publikation (Nr.) |
 EGU/EGU2015-1760.pdf |
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| Zusammenfassung |
| Dry spell lengths, DSL, defined as the number of consecutive days with daily rain amounts
below a given threshold, may provide relevant information about drought regimes. Taking
advantage of a daily pluviometric database covering a great extension of Europe, a detailed
analysis of the multifractality of the dry spell regimes is achieved. An autoregressive process
is applied with the aim of predicting DSL. A set of parameters, namely Hurst exponent, H,
critical Hölder exponent, α0, spectral width, W , and spectral asymmetry, B, permit a first
clustering of European rain gauges in terms of the complexity of their DSL series.
This set of parameters also allows distinguishing between time series describing
fine- or smooth-structure of the DSL regime by using the Complexity Index, CI.
Results of previous monofractal analyses also permit establishing comparisons
between fine and smooth-structures, correlation dimensions, predictive instability and
anti-persistence of DSL for European areas. Relationships are also found between the CI
and the mean absolute deviation, MAD, and the optimum autoregressive order,
OAO, of an AR(p) autoregressive process applied to the DSL series. The detailed
analysis of the discrepancies between empiric and predicted DSL underlines the
uncertainty over predictability of long DSL, particularly for the Mediterranean region. |
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