ENSO is the most prominent mode of coupled ocean-atmosphere variability in the Tropics on interannual time-scale. Numerous studies have shown its impact on rainfall in different parts of the world. In Africa some of the regions seem to be affected but the signal is not always very strong. This could be due to the remote location of this continent from the core of the ENSO anomalies and the influence of the Indian and Atlantic Oceans. These oceans have their own variability with strong regional impacts on rainfall and may modulate the ENSO signal.

This study is aimed at investigating the stability of the ENSO-African rainfall teleconnection over 3 different regions: Western, Eastern and Southern Africa. The wetter equatorial regions of central Africa are excluded due to their strong dependence on local water recycling. The 3 regions differ in seasonality and mechanisms of their respective rainy seasons which means different mechanisms for the teleconnection to ENSO.

The work uses two complementary approaches : - diagnostic studies of observed and reanalysed data - hypothesis testing through a set of numerical experiments with ARPEGE-Climat (Meteo-France) AGCM.