Structure and properties of the subsolar magnetopause for northward IMF: ISEE observations

Journal Article · Tue May 01 04:00:00 EDT 1990 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/JA095iA05p06375· OSTI ID:5048126

Song, P; Russell, C T ^[1]; Elphic, R C; Gosling, J T ^[2]; Cattell, C A ^[3]

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1. Univ. of California, Los Angeles (United States)
2. Los Alamos National Lab., NM (United States)
3. Univ. of California, Berkeley (United States)

Detailed magnetopause structure and properties for the magnetic field, electric field and plasma are examined for an ISEE 1 magnetopause crossing which occurred near the subsolar point when the interplanetary magnetic field (IMF) was strongly northward. Because the crossing is slow, the spatial variations in the plasma are clearly resolved. This example illustrates the nature of the steady state interface of two magnetized thermal plasma populations with parallel fields and can serve as a guide to theoretical modeling and simulations. The authors have found that the magnetopause is composed of three layers, a sheath transition layer, an outer boundary layer and an inner boundary layer. In the sheath transition layer, there is a gradual density decrease without a change in temperature. The transition layer occurs totally within the magnetosheath plasma. The outer boundary layer and the inner boundary layer are dominated by magnetosheath and magnetospheric particles, respectively. In each of the boundary layers, the plasma can be interpreted as simple mixtures of the magnetosheath and magnetospheric populations. No significant heating or cooling is seen across the magnetopause during this crossing. The plasma within each of these layers is quite uniform and their boundaries are sharp, suggesting that there is very little diffusion present. The sharp boundaries between the transition layer, the boundary layers and the magnetosphere are all thinner than an ion gyroradius. Transverse waves with right hand or linear polarization near the ion gyrofrequency are observed in the transition layer. These appear to be generated in the transition layer and to be a common feature of this layer when the IMF is northward.

• OSTI ID: 5048126
• Journal Information: Journal of Geophysical Research; (United States), Journal Name: Journal of Geophysical Research; (United States) Vol. 95:A5; 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
BOUNDARY LAYERS
ELECTRIC FIELDS
ENERGY TRANSFER
EXPLORER SATELLITES
INTERPLANETARY MAGNETIC FIELDS
LAYERS
MAGNETIC FIELDS
MAGNETIC RECONNECTION
MAGNETOPAUSE
MASS TRANSFER
MORPHOLOGY
PLASMA DENSITY
PLASMA DIAGNOSTICS
POLARIZATION
SATELLITES
SOLAR ACTIVITY
SOLAR WIND
VARIATIONS