Time evolution of short and intermediate term periodicities of electrons at geosynchronous orbit during solar cycle 23 and 24: A wavelet approach

► Using GOES data short and intermediate periodicities in energetic electron flares are investigated. ► Invoking wavelet power method, time variation of main quasi-periodicities is investigated. ► Quasi-periodic oscillations including a period of 22-35 day in high frequency range are detected. ► Quasi-periods of 40-60, 90-100 day and near Rieger periods are found. ► Explanations of periodicities are given in terms of previous results and r-mode oscillations.