Pc 1 pearl-electron interactions on the L = 4. 2 magnetic shell

Journal Article · Mon Aug 01 04:00:00 EDT 1983 · Geophys. Res. Lett.; (United States)

DOI:https://doi.org/10.1029/GL010i008p00627· OSTI ID:5541822

Arnoldy, R L; Kaufmann, R L; Cahill, Jr, L J; Mende, S B

A number of examples of auroral light bursts correlated with Pc 1 ''pearl'' wave packets have been recorded at Siple, Antarctica (L = 4.2 ). The events are unique in that an individual light burst occurs at Siple not when the wave packet is recorded at Siple but rather when the wave is measured to be at the conjugate point over Roberval, Quebec. Although one can fit the observations to a model where ions are precipitated from an interaction region near the equator via cyclotron resonance, the number of ions required to produce the light and the above mentioned light burst-ULF wave phase relationship both make the precipitation of electrons a more plausible interpretation. In an electron model, electrons are precipitated at Siple which have interacted with the Pc 1 wave packet over Roberval. Because of the South Atlantic magnetic anomaly, particle mirror points are nearly 200 km deeper in the atmosphere at Siple than at Roberval. Electrons of auroral energies (few keV) can be in longitudinal resonance with the Pc 1 waves over Roberval in the altitude range where the Alfven speed rapidly decreases (2000..-->..500 km). Low parallel velocities are possible for these electrons in this altitude range because the electrons are close to their mirror points. Those electrons in longitudinal resonance with the Pc 1 wave packet must have their mirror points lowered such that they do not reach the atmosphere at Roberval but are definetly precipitated at Siple. An interesting possibility is suggested in that these events represent the acceleration of electrons by a kinetic Alfven wave.

• Research Organization: Space Science Center, University of New Hampshire, Durham, NH 03824
• OSTI ID: 5541822
• Journal Information: Geophys. Res. Lett.; (United States), Journal Name: Geophys. Res. Lett.; (United States) Vol. 10:8; ISSN GPRLA
• Country of Publication: United States
• Language: English

Related Subjects

640203* -- Atmospheric Physics-- Magnetospheric Phenomena-- (-1987)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ACCELERATION
ALFVEN WAVES
AURORAE
CHARGED-PARTICLE PRECIPITATION
CYCLOTRON RESONANCE
EARTH ATMOSPHERE
ELECTRON PRECIPITATION
HYDROMAGNETIC WAVES
MAGNETOSPHERE
PLASMA ACCELERATION
PULSATIONS
RESONANCE