Magnetospheric particle injection and the upstream ion event of September 5, 1984

Journal Article · Mon Dec 01 04:00:00 EST 1986 · Geophys. Res. Lett.; (United States)

DOI:https://doi.org/10.1029/GL013i013p01376· OSTI ID:6838978

Krimigis, S M; Sibeck, D G; McEntire, R W

Energetic particle data from the AMPTE Charge Composition Explorer (CCE) spacecraft in the outer dayside magnetosphere are examined during the period of an upstream ion event observed by AMPTE Ion Release Module (IRM) spacecraft on September 5, 1984 (Moebius et al., this issue). The CCE data reveal the following: (a) an ion enhancement was observed at --0040 UT in near coincidence with a substorm onset at --0035 UT, approximately 15 minutes prior to the onset of the event upstream of the shock; (b) ions of both solar wind (He/sup + +/, Fe-group) and ionospheric (O/sup +/) origin over a broad energy range (--20 keV to >1350 keV) were injected at substorm onset; (c) the time evolution of the H/sup +/, He/sup + +/, and O/sup +/ pitch angle distributions markedly differed, with O/sup +/ exhibiting mostly enhancements at off-90/sup 0/ angles for the first hour after injection; (d) an enhancement in the Fe-group ions inside the magnetosphere at L--6.4 occurred simultaneously with the appearance of an O/sup +/ burst upstream of the shock. The CCE observations, taken together with the simultaneously observed IRM ion event, suggest that a plausible explanation for the appearence of upstream ions is leakage from the magnetosphere into the upstream region, rather than the alternate explanation which requires in-situ acceleration of solar wind ions via the Fermi mechanism.

• Research Organization: The Johns Hopkins University, Applied Physics Laboratory, Laurel, Maryland 20707
• OSTI ID: 6838978
• Journal Information: Geophys. Res. Lett.; (United States), Journal Name: Geophys. Res. Lett.; (United States) Vol. 13:13; ISSN GPRLA
• Country of Publication: United States
• Language: English

Related Subjects

640201* -- Atmospheric Physics-- Auroral
Ionospheric
& Magetospheric Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BEAM INJECTION
CHARGED PARTICLES
EARTH ATMOSPHERE
EARTH MAGNETOSPHERE
ENERGY LEVELS
EXPLORER SATELLITES
HELIUM IONS
INCLINATION
ION BEAM INJECTION
IONS
IRON IONS
MAGNETIC STORMS
OXYGEN IONS
SATELLITES
SHOCK WAVES
SOLAR ACTIVITY
SOLAR WIND