The composition, temperature, and density structure of cold ions in the quiet terrestrial plasmasphere: GEOS 1 results

Journal Article · Fri Sep 01 00:00:00 EDT 1989 · Journal of Geophysical Research; (USA)

DOI:https://doi.org/10.1029/JA094iA09p11865· OSTI ID:5837489

Farrugia, C J; Geiss, J; Balsiger, H ^[1]; Young, D T ^[2]

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1. Universitaet Bern (Switzerland)
2. Los Alamos National Lab., NM (USA)

The authors present a comprehensive study of the composition, and the density and temperature distributions of the thermal (energy {le} 110 eV) ion population in the terrestrial plasmasphere under quiet geomagnetic conditions. The data were collected by the Ion Composition Experiment (ICE) on board the European Space Agency's GEOS 1 satellite and cover the period from June 1977 to May 1978. They find typical quiet time proton densities to vary smoothly between {approximately} 10{sup 2} cm{sup {minus}3} (L {approx} 6) and 2 {times} 10{sup 3} cm{sup {minus}3} (L {approx} 3). In the local time sector 1,700-2,200 the equatorial proton concentration obeys an inverse fourth power dependence with dipole L. He{sup +} is a major ionic component in all L ranges investigated. Its concentration relative to H{sup +} is highly variable, ranging from {approximately} 1% to, on occasion, over 100%. The averaged variation of He{sup +} with dipole L in the 1,700-2,200 local time range shows a somewhat more rapid decrease with increasing L than does H{sup +}. The temperature in the quiet plasmasphere are between 4 {times} 10{sup 3} K and 1.5 {times} 10{sup 4} K and generally exhibit a slow increase with L value. The average radial temperature gradient near the equator is {approximately} 0.15 K/km. The main ionic constituents are usually in thermal equilibrium throughout the plasmasphere. Using alternate passes in the same region, they discuss the poststorm recovery of the plasmasphere on L shells > 4 for both H{sup +} and He{sup +}. Data are also presented on the minor ions O{sup +}, O{sup ++}, D{sup +}, and He{sup ++}.

• OSTI ID: 5837489
• Journal Information: Journal of Geophysical Research; (USA), Vol. 94:A9; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
PLASMASPHERE
ION DENSITY
ION TEMPERATURE
IONIC COMPOSITION
CATIONS
COMPARATIVE EVALUATIONS
DEUTERIUM IONS
GEOS SATELLITES
HELIUM IONS
OXYGEN IONS
PROTONS
BARYONS
CHARGED PARTICLES
EARTH ATMOSPHERE
EARTH MAGNETOSPHERE
ELEMENTARY PARTICLES
FERMIONS
HADRONS
IONS
NUCLEONS
SATELLITES
640201* - Atmospheric Physics- Auroral
Ionospheric
& Magetospheric Phenomena