Adiabatic modulation of equatorial pitch angle anisotropy

Journal Article · Thu Jun 01 04:00:00 EDT 1978 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JA083iA06p02675· OSTI ID:6673125

Kaye, S M; Lin, C S; Parks, G K; Winckler, J R

Particle measurements from the University of Minnesota detector aboard the geostationary ATS 6 satellite reveal striking equatorial pitch angle anisotropies. A study of 7 days of data shows a diurnal variation in anisotropy with J(..cap alpha..=40/sup 0/) >J(..cap alpha..=90/sup 0/) during times of low vertical-barBvertical-bar on the nightside and J(..cap alpha..=90/sup 0/) >J(..cap alpha..=40/sup 0/) during times of high vertical-barBvertical-bar on the dayside. Six representative anisotropy events are studied in finer detail. The 32- to 51-keV electron anisotropies increase and decrease with the total magnetic field intensity. The proton and higher energy electron anisotropies do not show as much variation. The particle anisotropies are studied in light of adiabatic and cyclotron resonance theory; the results indicate that adiabatic effects are the dominant modulation mechanism of particle pitch angle distributions in the outer radiation belt.

• Research Organization: Space Sciences Division, Geophysics Program, University of Washington, Seattle, Washington 98195
• OSTI ID: 6673125
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 83:A6; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

640203* -- Atmospheric Physics-- Magnetospheric Phenomena-- (-1987)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ANGULAR DISTRIBUTION
ANISOTROPY
ATS SATELLITES
CHARGED-PARTICLE PRECIPITATION
CYCLOTRON INSTABILITY
DISTRIBUTION
ELECTRON PRECIPITATION
INSTABILITY
PLASMA INSTABILITY
PLASMA MICROINSTABILITIES
PROTON PRECIPITATION
RADIATION BELTS
SATELLITES