A statistical study of EMIC waves as seen by the GOES satellites at geostationary orbit

During the recovery phase of geomagnetic storms the flux of high-energy electrons in the Earth’s radiation belts is controlled by a delicate balance of source and loss terms. Modeling the conditions in the radiation belts during the recovery phase depends on accurate input for the various terms, based on observational data. As of yet the relative importance of the various mechanisms is only poorly understood, however electromagnetic ion cyclotron (EMIC) waves are believed to play a crucial role as a loss mechanism. Using two years (2007-2008) of magnetic field data from the GOES 10, 11 and 12 satellites we computed dynamic spectra, in which we identified EMIC wave events. This dataset allows us to correlate the occurrence of EMIC wave events at geostationary orbit with external solar wind input parameters as well as internal magnetospheric activity indices. We also present examples where the flux of high-energy electrons measured by the satellites decreased during the occurrence of EMIC waves. Our analysis allows us to study the occurrence of EMIC waves as well as their influence on high-energy electron fluxes.