Heating of upflowing auroral H sup + and O sup + beams: Results from quasi-linear theory

Journal Article · Sun Jan 01 04:00:00 EST 1989 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/JA094iA01p00319· OSTI ID:5941046

Ludlow, G R; Kaufmann, R L ^[1]

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1. Univ. of New Hampshire, Durham (United States)

Particle measurements at 3 R{sub E} in the auroral zone revealed the existence of simultaneous upgoing hydrogen and oxygen beams on auroral field lines. The observed beam distributions were broad, indicating that significant heating took place near or below the satellite. The most interesting features that were noted in the distribution functions included extended parallel O{sup +} high energy and H{sup +} low energy tails, and a perpendicular broadening of the O{sup +} distribution. The purpose of the present work was to carry out an analysis of the mechanisms that could produce such heating, and to base this analysis as fully as possible on plasma and wave parameters measured by the Dynamics Explorer 1 (DE 1) satellite. An analysis of Maxwellian fits to the observed distribution functions showed that an oblique slow hydrogen acoustic mode was weakly unstable at frequencies between the oxygen and hydrogen gyrofrequencies. The location of wave-particle resonant and nonresonant regions in velocity space suggested qualitatively that H{sup +} undergoes weak parallel heating on the low velocity side of the beam and that O{sup +} is heated in the perpendicular direction on the high velocity side of the beam at satellite altitude. Energy is transferred from parallel motion of H{sup +} to perpendicular motion of O{sup +} during this process. Calculations of diffusion time scales for both H{sup +} and O{sup +} showed quantitatively that resonant diffusion within 1 R{sub E} of the satellite is sufficiently fast to explain the perpendicular O{sup +} heating and a substantial portion of the parallel H{sup +} heating.

• OSTI ID: 5941046
• Journal Information: Journal of Geophysical Research; (United States), Journal Name: Journal of Geophysical Research; (United States) Vol. 94:A1; ISSN 0148-0227; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

661320* -- Auroral
Ionospheric
& Magnetospheric Phenomena-- (1992-)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AURORAL ZONES
CATIONS
CHARGED PARTICLES
DIFFUSION
DISTRIBUTION
EXPLORER SATELLITES
HEATING
HYDROGEN IONS
HYDROGEN IONS 1 PLUS
ION DRIFT
IONS
OXYGEN IONS
QUASILINEAR PROBLEMS
SATELLITES
SPATIAL DISTRIBUTION
TEMPERATURE DISTRIBUTION