SIMULTANEOUS MEASUREMENTS OF WAVES AND PRECIPITATING ELECTRONS NEAR THE EQUATOR IN THE OUTER RADIATION BELT

An investigation of wave-particle interactions is made using several s imultaneous electron and wave measurements performed at near-equatoria l positions from the CRRES satellite. Bursts of electron precipitation were observed, most frequently at local times near dawn. Examples of bursts are presented in which the fluxes of the precipitating electron s and the wave intensities are correlated with coefficients as high as 0.7. During bursts the frequencies of the enhanced waves spanned a wi de range from 311 Hz to 3.11 kHz, and the energies of the enhanced ele ctrons were in the range 1.7 keV to 288 keV. The changes of the precip itating fluxes were generally less pronounced at the lowest energies. On the basis of electron cyclotron resonant calculations using the col d plasma densities and ambient magnetic fields taken from the CRRES me asurements it was found that the wave frequencies and precipitating el ectron energies were generally consistent with those expected from ele ctron resonance with parallel propagating whistler waves. The electron data of principal concern here were acquired in and about the loss co ne with narrow angular resolution spectrometers covering the energy ra nge 340 eV to 5 MeV. The wave data included electric field measurement s spanning frequencies from 5 Hz to 400 kHz and magnetic field measure ments from 5 Hz to 1O kHz.