Using observations of the Galileo PWS experiment, we show that energetic phenomena recurrently occur in the jovian magnetosphere. They are characterized by intensifications of the auroral radio emissions and the creation of new sources of radiations in the outer regions of the Io torus. Simultaneously, modifications of the structure of the plasmasheet are observed at large distance (more than 60 Rj) from Jupiter. These large-scale processes, presenting a periodicity of 50 to 80 hours, could be linked to global instabilities of the jovian magnetosphere. ¿ 1998 American Geophysical Union