Strong localized variations of the low-altitude energetic electron fluxes in the evening sector near the plasmapause

Abstract

Abstract. Speci®c type of energetic electron precipitation accompanied by a sharp increase in trapped energetic electron¯ux are found in the data obtained from lowaltitude NOAA satellites. These strongly localized variations of the trapped and precipitated energetic electron¯ux have been observed in the evening sector near the plasmapause during recovery phase of magnetic storms. Statistical characteristics of these structures as well as the results of comparison with proton precipitation are described. We demonstrate the spatial coincidence of localized electron precipitation with cold plasma gradient and whistler wave intensi®cation measured on board the DE-1 and Aureol-3 satellites. A simultaneous localized sharp increase in both trapped and precipitating electron¯ux could be a result of signi®cant pitch-angle isotropization of drifting electrons due to their interaction via cyclotron instability with the region of sharp increase in background plasma density.

Simultaneous measurements from the Millstone Hill radar and the Active satellite during the SAID/SAR arc event of the March 1990 CEDAR storm

“…7). Titova et al (1998) call it``cli''-like due to the sharpness of the increase of the trapped energetic electron¯ux at one side and report about burst-like spikes of the precipitating¯uxes. The same energetic electron behaviour is observed by the three detectors of the SPE-1 device onboard Active during its over¯ight above the radar.…”

“…The simultaneous sharp increase in both trapped and precipitating electron uxes of ring current energies can be the result of signi®cant pitch-angle isotropisation of drifting electrons caused by their interaction via the cyclotron instability at the background of increased thermal plasma density as it is present at the plasmapause or at detached regions of enhanced thermal plasma density. Theoretical explanations for this process are given by Trakhtengerts et al (1996) and Pasmanik et al (1998).…”

Spectral characteristics of waves and particles in the model of cyclotron wave-particle interactions near plasmapause

“…2 tained from experimental data (see for example Yahnina et al, 1996;Titova et al, 1997). Consideration of ®nite spread of energetic particles over energies and studying the wave spectrum provides a wider area of application of this model to the analysis of experimental data.…”

Victor Trakhtengerts: His contribution to space plasma physics

“…For example, in [33] they proposed a theory of gap formation in the electron component of a radiation belt, which took into account the diffusion of particles in L shells. Localized precipitations of energetic electrons in the duskside sector (at around the plasmasphere bulge) were found in [34] and analyzed in [35]. A general quasi linear theory was built for the interaction of whistler waves with electrons, which took into account the mode structure of the electromagnetic field in a plasma waveguide [36].…”