Electron velocity distributions near the earth's bow shock

Journal Article · Sat Jan 01 04:00:00 EST 1983 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JA088iA01p00096· OSTI ID:6079291

Feldman, W C; Anderson, R C; Bame, S J; Gary, S P; Gosling, J T; McComas, D J; Thomsen, M F; Paschmann, G; Hoppe, M M

A survey of two-dimensional electron velocity distributions, f(V), measured near the earth's bow shock using Los Alamos/Garching plasma instrumentation aboard ISEE 2 is presented. This survey provides clues to the mechanisms of electron thermalization within the shock and the relaxation of both the upsteam and downstream velocity distributions. First, near the foreshock boundary, fluxes of electrons having a power law shape at high energies backstream from the shock. Second, within the shock, cuts through f(V) along B. f(V), often show single maxima offset toward the magnetosheath by speeds comparable to, but larger than, the upstream thermal speed.Third, magnetosheath distributions generally have flat tops out to an energy, E/sub 0/, with maxima substantially lower than that in the solar wind. Occasionally, cuts through f(V) along B show one and sometimes two small peaks at the edge of the flat tops making them appear concave upward. The electron distributions characteristic of these three regions are interpreted as arising from the effects of macroscopic (scale size comparable to or larger than the shock width) electric and magnetic fields and the subsequent effects of microscopic (scale size small in comparison with the shock width) fields. In particular, our results suggest that field-aligned instabilities are likely to be present in the earth's bow shock.

• Research Organization: Los Alamos National Laboratory, Los Alamos, New Mexico 87545
• OSTI ID: 6079291
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 88:A1; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

640203* -- Atmospheric Physics-- Magnetospheric Phenomena-- (-1987)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BACKSCATTERING
DISTRIBUTION FUNCTIONS
EARTH ATMOSPHERE
ELECTRON SPECTRA
FUNCTIONS
INTERPLANETARY MAGNETIC FIELDS
INTERPLANETARY SPACE
MAGNETIC FIELDS
MAGNETOSHEATH
MAGNETOSPHERE
SCATTERING
SOLAR ACTIVITY
SOLAR WIND
SPACE
SPECTRA