An extended study of the low-latitude boundary layer on the dawn and dusk flanks of the magnetosphere

Journal Article · Wed Jul 01 00:00:00 EDT 1987 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/JA092iA07p07394· OSTI ID:5557205

Mitchell, D G; Kutchko, F; Williams, D J ^[1]; Eastman, T E; Frank, L A ^[2]; Russell, C T ^[3]

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1. Johns Hopkins Univ., Laurel MD (United States)
2. Univ. of Iowa, Iowa City (United States)
3. Univ. of California, Los Angeles (United States)

The authors present a study of the low-latitude boundary layer (LLBL) using ISEE 1 energetic particle, plasma, and magnetic field data obtained during numerous traversals of the LLBL that occurred on 66 ISEE 1 passes through the magnetospheric flank LLBL region. They use energetic particle distributions to determine dawn and dusk LLBL behavior and topology for varying orientations of the magnetosheath and/or interplanetary magnetic field (M/IMF), for different local times, and for changing levels of geomagnetic activity (Kp). This study corroborates and extends the earlier work of Williams et al. (1985) who presented a detailed study of two (dusk and dawn) ISEE 1 passes through the LLBL region for the case of northward M/IMF. They find that the dawn and dusk LLBL are on closed geomagnetic field lines for northward M/IMF but are on a combination of closed and open field lines for a southward M/IMF. The energetic particle distributions show that cases of reverse-draped field lines in the LLBL are consistent with an open field line topology. In addition, they find that the LLBL is thicker (thinner) for northward (southward) M/IMF and becomes thicker with increasing distance from the subsolar point. LLBL electric fields nominally are in the few (3-5) millivolts per meter range and display an apparent maximum value of {approximately}10mV/m. These electric fields capture magnetospherically drifting particles as they approach the LLBL and propel them tailward. In this way, the plasma sheet is the dominant source of energetic ({approx gt}10 keV) particles in the LLBL while the magnetosheath appears to be the dominant source for lower-energy ({approx lt}10 keV) LLBL particles.

• OSTI ID: 5557205
• Journal Information: Journal of Geophysical Research; (United States), Journal Name: Journal of Geophysical Research; (United States) Vol. 92:A7; 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
BOUNDARY LAYERS
DATA ANALYSIS
DIMENSIONS
DISTRIBUTION
EARTH ATMOSPHERE
EARTH MAGNETOSPHERE
ELECTRIC FIELDS
ELECTRONS
ELEMENTARY PARTICLES
EXPLORER SATELLITES
FERMIONS
GEOMAGNETIC FIELD
INTERPLANETARY MAGNETIC FIELDS
LAYERS
LEPTONS
MAGNETIC FIELDS
MAGNETOSHEATH
MATHEMATICS
ORIENTATION
PLASMA DRIFT
PLASMA SHEET
SATELLITES
SPATIAL DISTRIBUTION
THICKNESS
TOPOLOGY
TRAPPED ELECTRONS