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| Titel |
The sensitivity of warm period precipitation forecasts to various modifications of the Kain-Fritsch Convective Parameterization scheme |
| VerfasserIn |
N. Mazarakis, V. Kotroni, K. Lagouvardos, A. A. Argiriou, C. J. Anderson |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1561-8633
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| Digitales Dokument |
URL |
| Erschienen |
In: Natural Hazards and Earth System Science ; 11, no. 5 ; Nr. 11, no. 5 (2011-05-12), S.1327-1339 |
| Datensatznummer |
250009415
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| Publikation (Nr.) |
 copernicus.org/nhess-11-1327-2011.pdf |
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| Zusammenfassung |
The sensitivity of quantitative precipitation forecasts to various
modifications of the Kain-Fritsch (KF) convective parameterization scheme
(CPS) is examined for twenty selected cases characterized by intense
convective activity and widespread precipitation over Greece, during the warm
period of 2005–2007. The study is conducted using the MM5 model with a two
nested domains strategy, with horizontal grid increments of 24 and 8 km,
respectively. Five modifications to the KF CPS, each designed to test the
sensitivity of the model to the convective scheme formulation, are discussed.
The modifications include: (i) the maximization of the convective scheme
precipitation efficiency, (ii) the change of the convective time step,
(iii) the forcing of the convective scheme to produce more/less cloud
material, (iv) changes to the trigger function and (v) the alteration of the
vertical profile of updraft mass flux detrainment.
The simulated precipitation from the 8-km grid is verified against raingauge
measurements. Although skill scores vary widely among the cases and the
precipitation thresholds, model results using the modifications of the
convective scheme show improvements in 6-h precipitation totals compared to
simulations generated using the unmodified convective scheme. In general,
forcing the model to produce less cloud material improves the precipitation
forecast for the moderate and high precipitation amounts, while the same
modification and the change of the convective time step to 1 min has the
same result for the high precipitation thresholds. The increase of convective
time step to 15 min, the maximization of precipitation efficiency and the
changes to the trigger function give similar results for medium and high
precipitation. On the other hand, the forecast for the light precipitation is
improved by forcing the model to produce more cloud material as well as by the
alteration of the vertical profile of updraft mass flux detrainment. |
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