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Titel |
Complex behaviour and predictability of the European dry spell regimes |
VerfasserIn |
X. Lana, M. D. Martínez, C. Serra, A. Burgueño |
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 ; 17, no. 5 ; Nr. 17, no. 5 (2010-09-30), S.499-512 |
Datensatznummer |
250013728
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Publikation (Nr.) |
copernicus.org/npg-17-499-2010.pdf |
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Zusammenfassung |
The complex spatial and temporal characteristics of European dry spell
lengths, DSL, (sequences of consecutive days with rainfall amount below a
certain threshold) and their randomness and predictive instability are
analysed from daily pluviometric series recorded at 267 rain gauges along the
second half of the 20th century. DSL are obtained by considering four
thresholds, R0, of 0.1, 1.0, 5.0 and 10.0 mm/day. A proper quantification
of the complexity, randomness and predictive instability of the different DSL
regimes in Europe is achieved on the basis of fractal analyses and dynamic
system theory, including the reconstruction theorem. First, the concept of
lacunarity is applied to the series of daily rainfall, and the lacunarity
curves are well fitted to Cantor and random Cantor sets. Second, the rescaled
analysis reveals that randomness, persistence and anti-persistence are
present on the European DSL series. Third, the complexity of the physical
process governing the DSL series is quantified by the minimum number of
nonlinear equations determined by the correlation dimension. And fourth, the
loss of memory of the physical process, which is one of the reasons for the
complex predictability, is characterized by the values of the Kolmogorov
entropy, and the predictive instability is directly associated with positive
Lyapunov exponents. In this way, new bases for a better prediction of DSLs in
Europe, sometimes leading to drought episodes, are established. Concretely,
three predictive strategies are proposed in Sect. 5. It is worth mentioning
that the spatial distribution of all fractal parameters does not solely
depend on latitude and longitude but also reflects the effects of orography,
continental climate or vicinity to the Atlantic and Arctic Oceans and
Mediterranean Sea. |
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