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| Titel |
Multiscale behavior of the ALARO-0 model for simulating extreme summer precipitation climatology |
| VerfasserIn |
Rozemien De Troch, Rafiq Hamdi, Hans Van de Vyver, Jean-François Geleyn, Piet Termonia |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250072420
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| Zusammenfassung |
| Daily summer precipitation over Belgium from the ALADIN model and a new version of the model including a new parameterization of deep convection and microphysics, ALARO-0, are compared with respect to station observations for the period 1961-1990. ERA-40 reanalyses are dynamically downscaled using both models on a horizontal resolution of 40 km, followed by a one-way nesting on high spatial resolutions of 10 and 4 km. This set-up allows us to explore the relative importance of spatial resolution versus parameterization formulation on the model skill to simulate correctly extreme daily precipitation. In order to put our simulations into a larger context of the state-of-the-art regional climate modeling, the ALADIN-Climate model is added to the evaluation. Model performances are assessed through standard statistical errors, density-, frequency-, and quantile distributions as well as extreme value analysis, using the peak-over-threshold method and Generalized Pareto Distribution. Results for the 40 km simulations show a similar behavior for ALADIN and ALARO-0, both reproducing the observations reasonably well. At the higher resolutions, ALARO-0 approaches at 10 and 4 km much better the observations than ALADIN, which gives consistently too high precipitation rates. Our findings demonstrate that the new parameterization within ALARO-0 is responsible for a correct simulation of extreme summer precipitation at various horizontal resolutions. Moreover, this study shows that ALARO-0 and the used model set-up can compete with other state-of-the-art models used for regional climate modeling. |
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