We present data from a number of ground stations and satellites that reveal an example of a previously unreported type of global event. The event is characterized by the occurrence of monochromatic pulsations of widely varying frequencies in different regions of local times and L shells. The pulsations appear to be modulated with a ∼45 min periodicity. Simultaneously, energetic particle fluxes observed at geosynchronous orbit (with energies resulting in a drift period of ∼45 min) appear to become phase bunched and the pulsations are observed to occur coincident with minima in the particle bunching. Corresponding data from GOES 5 show an increase in the compressional component of the magnetic field with this period. Data from South Pole Station show fluctuations in the east–west component of the magnetic field at half this period, along with a weak auroral signature and riometer absorptions. We conclude that the data show the existence of a global disturbance with a compressional magnetic field signature, and we suggest that this compression induces a radial electric field, based on Faraday's law. Phase bunching of energetic electrons (due to the induction electric field) and monochromatic pulsations are consequences of the global disturbance, although the mechanism responsible for exciting the pulsations is not clear.
