THE CHARGED-PARTICLE FLUXES AT AURORAL AND POLAR LATITUDES AND RELATED LOW-FREQUENCY AURORAL KILOMETRIC RADIATION-TYPE AND HIGH-FREQUENCY WIDE-BAND EMISSION

The results of simultaneous observations of charged particle fluxes wi thin the energy range 50 eV to 20 keV (plasma energy-angle spectromete r, PEAS experiment) and plasma waves within the frequency range 0.1 to 10 MHz (plasma radio spectrometer, PRS 3 experiment) on board the APE X spacecraft are presented. The data were obtained at polar and aurora l latitudes in the dawn-dusk and noon-midnight time sectors. The low-f requency (LF) sporadic emission mainly on frequencies lower than the l ocal gyrofrequency was commonly observed within a comparatively narrow latitude interval (similar to 5 degrees - 6 degrees) of the amoral ov al. The maximum of spectral wave intensity was revealed at a frequency of similar to 200 kHz. The sporadic character of the observed emissio ns, the spectra, are very similar to those reported for amoral kilomet ric radiation (AKR), and the temporal and spatial occurrences imply it s relation to the source of AKR emissions measured at the higher altit udes, with regards to our wave measurements as LF AKR-type emissions. Comparative analysis of spatial distributions of charged particle ener gy spectra and variations of wave spectra at amoral oval latitudes sho wed that several conditions should be fulfilled for LF AKR generation. These conditions are related both to the intensity and energy of prec ipitating ion and electron fluxes, and to albedo electrons and the ion ospheric plasma parameters. The wideband HF emission was observed toge ther with the LF AKR-type emission during the morning amoral oval cros sing. At spacecraft apogee altitudes, in the polar cap zone intense el ectron precipitations and an increase of plasma noise intensity at fre quencies equal or below f(He) were observed at the period when the IMF was northward. These precipitations and emissions were accompanied by the horizontal currents crossing the polar cap, the so-called theta s tructure.