Ion precipitation from the magnetopause current sheet

Journal Article · Mon Jun 01 04:00:00 EDT 1987 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/JA092iA06p06147· OSTI ID:5962483

Lyons, L R; Vampola, A L ^[1]; Speiser, T W ^[2]

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1. Aerospace Corp., Los Angeles, CA (United States)
2. Univ. of Colorado, Boulder (United States) NOAA Space Environment Lab., Boulder, CO (United States)

Measurements from the polar-orbiting S3-3 satellite show that energetic ions frequently precipitate with isotropic pitch angle distributions at auroral latitudes on the dayside. The authors propose that this precipitation results from non-guiding center motion of radiation belt ions that drift into the magnetopause current sheet. They also propose that the ion precipitation and flows of energetic ions observed in the magnetosheath originate together within the magnetopause current sheet. Ions ejected from the magnetopause towad the earth lfow along open field lines that are adjacent to the separatrix between open and closed field lines. Those ejected into the magnetosheath flow along field lines that are connected to the geomagnetic field and adjacent to the separatrix between the connected field lines and purely magnetosheath fields lines. These proposals are tested by comparing the S3-3 observations of precipitating ions with previously analyzed ISEE 1 observatons of energetic ions obtained nearr the magnetopause and in the magnetosheath. The S3-3 observations imply that the region of ion precipitation is often continuous as a function of local time. This suggests that at least on the dayside there is often a continuous shell of magnetospheric ions within the magnetosheath flowing from the magnetosphere. These ions are likely an important source for energetic ions in the interplanetary medium.

• OSTI ID: 5962483
• Journal Information: Journal of Geophysical Research; (United States), Journal Name: Journal of Geophysical Research; (United States) Vol. 92:A6; ISSN 0148-0227; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

661320* -- Auroral
Ionospheric
& Magnetospheric Phenomena-- (1992-)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AURORAL ZONES
CHARGED PARTICLES
CHARGED-PARTICLE PRECIPITATION
COMPARATIVE EVALUATIONS
ENERGY SPECTRA
EVALUATION
GEOMAGNETIC FIELD
GUIDING-CENTER APPROXIMATION
INTERPLANETARY SPACE
ION DRIFT
IONS
ISOTROPY
MAGNETIC FIELDS
MAGNETOPAUSE
MAGNETOSHEATH
ORIGIN
RADIATION BELTS
SATELLITES
SPACE
SPECTRA