The aim of this study is to describe the African monsoon synoptic variability and investigate the ability of the Meteo-France GCM to reproduce that variability. This study is carried out in the frame of the West African Monsoon Project (EU Project).
Several variables will be considered in order to characterize the synoptic variability (mainly due to the African easterly waves), such as dynamical ones (vorticity, divergence, moisture convergence), thermodynamical ones (moist static stability, precipitations, OLR) and the equivalent potential vorticity. Two kind of data will be used as references for the 10 year period 1979 to 1988, the ECMWF reanalyses and observed data (namely precipitations and OLR). The variability will be quantified per season or month, with the help of a space-time spectral analysis and a complex principal component analysis of the time filtered variables (in the spectral window defined with the previous method). A particular attention will be devoted to the intraseasonal modulation of the synoptic activity.
The 10 year Meteo-France GCM simulation will be studied, using the same
variables and methods in order to validate the African monsoon synoptic variability