Climate simulation over CORDEX Africa domain using the fifth-generation Canadian Regional Climate Model (CRCM5)

Hernández-Díaz, Leticia; Laprise, René; Sushama, Laxmi; Martynov, Andrey; Winger, Katja et Dugas, Bernard (2013). « Climate simulation over CORDEX Africa domain using the fifth-generation Canadian Regional Climate Model (CRCM5) ». Climate Dynamics, 40(5-6), pp. 1415-1433.

Fichier(s) associé(s) à ce document :

Prévisualisation	PDF Télécharger (2MB)

Résumé

The new fifth-generation Regional Climate Model (CRCM5) was driven by ERA reanalyses for the period 1984–2008 over the African continent following the CORDEX experimental protocol. Overall the model succeeds in reproducing the main features of the geographical distribution and seasonal cycle of temperature and precipitation, the diurnal cycle of precipitation, and the West African Monsoon (WAM). Biases in surface temperature and precipitation are discussed in relation with some circulation defects noted in the simulation. In the African regions near the equator, the model successfully reproduces the double peak of rainfall due to the double passage of the tropical rainbelt, although it better simulates the magnitude and timing of the second peak of precipitation. CRCM5 captures the timing of the monsoon onset for the Sahel region but underestimates the magnitude of precipitation. The simulated diurnal cycle is quite well simulated for all of the regions, but is always somewhat in advance for the timing of rainfall peak. In boreal summer the CRCM5 simulation exhibits a weak cold bias over the Sahara and the maximum temperature is located too far south, resulting in a southward bias in the position of the Saharan Heat Low. The region of maximum ascent in the deep meridional circulation of the Hadley cell is well located in the CRCM5 simulation, but it is somewhat too narrow. The core of the African Easterly Jet is of the right strength and almost at the right height, but it is displayed slightly southward, as a consequence of the southward bias in the position of the Saharan Heat Low and the thermal wind relationship. These biases appear to be germane to the WAM rainfall band being narrower and not moving far enough northward, resulting in a dry bias in the Sahel.

Type:	Article de revue scientifique
Mots-clés ou Sujets:	Regional Climate Modelling, Africa, West African Monsoon, CORDEX
Unité d'appartenance:	Centres institutionnels > Centre pour l'étude et la simulation du climat à l'échelle régionale (ESCER) Faculté des sciences > Département des sciences de la Terre et de l'atmosphère
Déposé par:	René Laprise
Date de dépôt:	01 avr. 2016 18:14
Dernière modification:	19 avr. 2016 18:15
Adresse URL :	http://archipel.uqam.ca/id/eprint/8059

Modifier les métadonnées (propriétaire du document)

Statistiques