Physics
Scientific paper
Jun 1998
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1998georl..25.2017c&link_type=abstract
Geophysical Research Letters, Volume 25, Issue 12, p. 2017-2020
Physics
169
Magnetospheric Physics: Auroral Phenomena, Ionosphere: Particle Acceleration, Magnetospheric Physics: Current Systems, Ionosphere: Ionosphere/Magnetosphere Interactions
Scientific paper
Observations of plasma particles and fields by the FAST satellite find evidence of acceleration of intense upgoing electron beams by quasi-static parallel electric fields. The beam characteristics include a broad energy spectrum with peak energies between 100 eV and 5 keV, perpendicular temperatures less than 1 eV, and fluxes greater than 109/cm2sec. Diverging electrostatic shocks associated with the beams have integrated potentials that match the beam energy. These beams are found in regions of downward Birkeland current and account for the total field-aligned current when they are present. The most energetic ion conics in the auroral zone are found coincident with these beams, in agreement with the model for ``trapped'' conics. The measured particle densities of the electron beams and associated ion conics are approximately equal and typically range from 1 to 10 cm-3, with no evidence for additional cold density. The beams are seen frequently at altitudes between 2000 and 4000 km in the winter auroral zone. Their probability of occurrence has a strong dependence on season and altitude and is similar to that for upgoing ion beams in the adjacent upward current regions. This similarity suggests that the density and scale height of ionospheric ions play an important role in the formation of both types of beams.
Carlson Carl W.
Cattell Cynthia
Elphic Richard
Ergun Robert E.
Klumpar D. M.
No associations
LandOfFree
FAST observations in the downward auroral current region: Energetic upgoing electron beams, parallel potential drops, and ion heating does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with FAST observations in the downward auroral current region: Energetic upgoing electron beams, parallel potential drops, and ion heating, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and FAST observations in the downward auroral current region: Energetic upgoing electron beams, parallel potential drops, and ion heating will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1332064