On the origins of energetic ions in the Earth's dayside magnetosheath

Journal Article · Mon Dec 31 23:00:00 EST 1990 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/90JA01751· OSTI ID:5223786

Fuselier, S A; Klumpar, D M; Shelley, E G ^[1]

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1. Lockheed Palo Alto Research Lab., CA (USA)

Energetic ion events in the Earth's dayside subsolar magnetosheath (0900 - 1300 Local Time) are surveyed using data from the Active Magnetospheric Particle Tracer Explorers/Charge Composition Explorer (AMPTE/CCE) Hot Plasma Composition Experiment. Ion species carrying the signature of their origin (O{sup +} and energetic He{sup 2+}) are used to distinguish between magnetospheric and solar wind orgins for the energetic ion events. The results of this survey indicate that the majority of energetic (10-17 keV/e) H{sup +} and He{sup 2+} ions observed in the dayside magnetosheath are accelerated from the solar wind population. The energetic He{sup 2+} to H{sup +} density ratio in the magnetosheath is consistent with that predicted from first-order Fermi acceleration of solar wind ions in the turbulent regions upstream and downstream from the Earth's quasi-parallel bow shock. Although the majority of the energetic ions appear to be of solar wind origin, magnetospheric O{sup +} is also occasionally present in the magnetosheath. The simultaneous occurence of both energetic He{sup 2+} and magnetospheric O{sup +} indicates that, on occasion, both Fermi acceleration of solar wind ions and leakage of magnetospheric ions occurs in the dayside magnetosheath.

• OSTI ID: 5223786
• Journal Information: Journal of Geophysical Research; (United States), Journal Name: Journal of Geophysical Research; (United States) Vol. 96:A1; ISSN 0148-0227; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

640201* -- Atmospheric Physics-- Auroral
Ionospheric
& Magetospheric Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ACCELERATION
BARYONS
CHARGED PARTICLES
EARTH ATMOSPHERE
EARTH MAGNETOSPHERE
ELEMENTARY PARTICLES
EXPLORER SATELLITES
FERMIONS
HADRONS
HELIUM IONS
ION DENSITY
IONIC COMPOSITION
IONS
MAGNETOSHEATH
NUCLEONS
ORIGIN
OXYGEN IONS
PROTONS
SATELLITES
SOLAR ACTIVITY
SOLAR WIND