The influence of intraseasonal oscillations on rainfall variability over Central Africa: case of the 25-70 days variability.

The influence of intra-seasonal oscillations (ISO) on rainfall in Central Africa (CA) during the March-May (MAM) season is assessed using the National Oceanic and Atmospheric Administration Climate Prediction Center daily gridded rainfall data. ISO indices are defined using the time series analysis of the first two principal components resulting from the empirical orthogonal function, applied to daily filtered outgoing longwave radiation. Based on these indices, a total of 71 strong Intraseasonal Events (SIEs) and 66 weak Intraseasonal Events (WIEs) were selected using threshold method.