The precipitation of relativistic electrons near the trapping boundary

Journal Article · Mon Apr 01 04:00:00 EST 1991 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/90JA02343· OSTI ID:5258234

Imhof, W L; Voss, H D; Mobilia, J; Datlowe, D W; Gaines, E E ^[1]

---

1. Lockheed Palo Alto Research Lab., Palo Alto, CA (USA)

Highly relativistic electrons are known to be present at synchronous satellite altitude in time-varying and sometimes large intensities; it is therefore important to consider the fluxes and locations of relativistic electrons precipitating into the atmosphere. Here the authors present measurements from the low-altitude three-axis-stabilized satellite S81-1 of trapped and precipitating electrons from 6 keV to above 1 MeV. Significant fluxes of precipitating relativistic electrons above 1 MeV within the bounce loss cone are much more often observed near midnight than noon and generally in narrow spikes <100 km in width typically at L values between 4 and 6 near the radiation belt boundary. The tendency for many of the relativistic spikes to be near the trapping boundary is consistent with the general pattern at lower energies confirmed by the measurements presented here of intensity and threshold energy for isotropy versus L shell. A trend was observed for the higher-energy precipitating electron fluxes to peak at somewhat lower L values. The precipitation of > 1-MeV electrons has been measured to occur at intensities and in locations that are widely variable within a few minutes superposed on longer-term variations. On one of the days of strongest precipitation the total nighttime input to the atmosphere during 12 hours from >1-MeV electrons within the bounce loss cone near teh trapping boundary was {approximately}10{sup 19} ergs, which was an order of magnitude less than the loss rates estimated by Baker et al. from high-altitude measurements, suggesting that precipitation in the drift loss cone may be significant.

• OSTI ID: 5258234
• Journal Information: Journal of Geophysical Research; (United States), Journal Name: Journal of Geophysical Research; (United States) Vol. 96:A4; ISSN 0148-0227; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

640201* -- Atmospheric Physics-- Auroral
Ionospheric
&amp; Magetospheric Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALTITUDE
BOUNDARY LAYERS
CHARGED-PARTICLE PRECIPITATION
ELECTRON PRECIPITATION
ELECTRONS
ELEMENTARY PARTICLES
ENERGY RANGE
FERMIONS
ISOTROPY
LAYERS
LEPTONS
LOSS CONE
LOSSES
PLASMA DENSITY
RADIATION BELTS
RELATIVISTIC RANGE
SATELLITES
TRAPPED ELECTRONS
VARIATIONS