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Uncertainties in the Annual Cycle of Rainfall Characteristics over West Africa in CMIP5 Models

Sow, Magatte; Diakhaté, Moussa; Dixon, Ross D.; Guichard, Françoise; Dieng, Diarra; Gaye, Amadou T.

We analyse uncertainties associated with the main features of the annual cycle of West African rainfall (amplitude, timing, duration) in 15 CMIP5 simulations over the Sahelian and Guinean regions with satellite daily precipitation estimates. The annual cycle of indices based on daily rainfall such as the frequency and the intensity of wet days, the consecutive dry (CDD) and wet (CWD) days, the 95th percentile of daily rainfall (R95), have been assessed. Over both regions, satellite datasets provide more consistent results on the annual cycle of monthly precipitation than on higher-frequency rainfall indices, especially over the Guinean region. By contrast, CMIP5 simulations display much higher uncertainties in both the mean precipitation climatology and higher-frequency indices. Over both regions, most of them overestimate the frequency of wet days. Over the Guinean region, the difficulty of models to represent the bimodality of the annual cycle of precipitation involves systematic biases in the frequency of wet days. Likewise, we found strong uncertainties in the simulation of the CWD and the CDD over both areas. Finally, models generally provide too early (late) onset dates over the Sahel (the Guinean region) and overestimate rainfall during the early and late monsoon phases. ... mehr

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Verlagsausgabe §
DOI: 10.5445/IR/1000118019
Veröffentlicht am 03.04.2020
Cover der Publikation
Zugehörige Institution(en) am KIT Institut für Meteorologie und Klimaforschung - Atmosphärische Umweltforschung (IMK-IFU)
Publikationstyp Zeitschriftenaufsatz
Publikationsjahr 2020
Sprache Englisch
Identifikator ISSN: 2073-4433
KITopen-ID: 1000118019
HGF-Programm 12.02.03 (POF III, LK 01)
Regional Climate-and Water Cycle Variab.
Erschienen in Atmosphere
Band 11
Heft 2
Seiten Article: 216
Vorab online veröffentlicht am 20.02.2020
Schlagwörter West Africa; rainfall; annual cycle; CMIP5 models; onset; cessation; extremes; uncertainties
Nachgewiesen in Scopus
Web of Science
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