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| Titel |
Modelling maximum monthly precipitation in temporal climate evolution |
| VerfasserIn |
Dionysia Panagoulia, Chrys Caroni |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250051085
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| Zusammenfassung |
| The objective of this study was to explore the fitting of generalized extreme value
(GEV) distributions to maximum monthly precipitation in the temporal evolution of
climate over the Mesochora catchment in central-western Greece. Precipitation was
modelled as a stochastic process coupled with atmospheric circulation models. An
automated and objective classification of daily patterns (CPs) based on optimized
fuzzy rules was used to classify both observed CPs and ECHAM4 GCM-generated
CPs for 1xCO2 and 2xCO2 climate scenarios. We fitted the GEV distribution by
maximum likelihood to the series of maximum daily precipitation for each month
separately, over the period 1972-1992 for historical data, 1961-2000 for 1xCO2, and
2061-2100 for 2xCO2. The significance of non-stationarity over time in the GEV
parameters of location μ(t) and scale Ïă(t) was examined by comparing alternative
models by likelihood ratio tests. The historical data were generally fitted well by
the stationary model, although trends were found in January (steady decline; P =
0.014) and February (increasing to 1986, then decreasing; P = 0.035). The 1xCO2
series were also stationary with the exception of August (P = 0.003) and November
(P = 0.027). Maxima for August tended to increase for the first half of the period
1961-2000, then decrease, while maxima for November showed the opposite pattern. In
the 2xCO2 scenario, maxima for May tended to decrease throughout the period
2061-2100 (P = 0.006). Maxima for August (P = 0.002) and September (P = 0.026)
decreased in the last few years of the period, while maxima for April (P = 0.036) and
November (P = 0.006) increased towards the end of the period. The stationary GEV
distribution was a satisfactory fit to the 2xCO2 series of the remaining seven months. |
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