Pc 3 magnetic pulsations and precipitation of energetic electrons

Journal Article · Wed Aug 01 04:00:00 EDT 1979 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JA084iA08p04125· OSTI ID:5755349

Arthur, C W; Bjordal, J; Rosenberg, T J

Data from the synchronous altitude satellite ATS 1 and near-conjugate measurements of bremsstrahlung X rays and ground magnetic variations have been used to analyze an event of modulated auroral zone electron precipitation and magnetic pulsations in the Pc 3 range. Transverse, azimuthal, nearly linearly polarized waves, strongly peaked at approx.25-s period were observed at ATS 1 from 0600 to 1000 LT on August 18, 1967, diminishing in intensity thereafter. Weak pulsations with periods < or approx. =18 s and wave properties similar to the above followed in the interval from 1300 to 1700 LT. Ground magnetic pulsations at College, Alaska, were observed mainly in the transverse H and D components with maximum power spectral density in the period range 25--40 s prior to 1300 LT and from 20 to 30 s thereafter.lity at the magnetopause. The observed wave periods can be accounted for by a field line distribution of plasma density of the form r/sup -4/ with equatorial values at r=6.6R/sub e/ of order 1 cm/sup -3/. The wave resonance model can satisfactorily explain observed differences in the pulsation activity at the ground, balloon, and satellite if account is taken of the spatial sensitivities of the different techniques and the location of observing sites with respect to the probable location of resonant field lines. Although the event pertains to a disturbed period, there is insufficient evidence to associate gross temporal changes in the intensity of pulsation activity with the occurrence of specific substorms. However, the data suggest that electron precipitation pulsations will be found to correlate with Pc 3 magnetic pulsations when substorm injections coupled with azimuthal drift provide enhanced energetic particle fluxes within dayside resonance regions.

• Research Organization: Space Sciences Laboratory, Marshall Space Flight Center, Huntsville, Alabama 35812
• OSTI ID: 5755349
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 84:A8; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

640203* -- Atmospheric Physics-- Magnetospheric Phenomena-- (-1987)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ATS SATELLITES
AURORAL ZONES
CHARGED-PARTICLE PRECIPITATION
EARTH ATMOSPHERE
ELECTRON PRECIPITATION
ELECTRONS
ELEMENTARY PARTICLES
FERMIONS
HELMHOLTZ INSTABILITY
INSTABILITY
LEPTONS
MAGNETIC BAYS
MAGNETOPAUSE
MAGNETOSPHERE
PLASMA DENSITY
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
PULSATIONS
SATELLITES
TRAPPED ELECTRONS