Observations of the magnetopause current layer: Cases with no boundary layer and tests of recent models. Final report, 20 January 1995

Technical Report · Sun Jan 01 04:00:00 EST 1995

OSTI ID:42792

Eastman, T E

Evidence for the probable existence of magnetospheric boundary layers was first presented by Hones, et al., based on VELA satellite plasma observations (no magnetic field measurements were obtained). This magnetotail boundary layer is now known to be the tailward extension of the high-latitude boundary layer or plasma mantle (first uniquely identified using HEOS 2 plasma and field observations by Rosenbauer et al.) and the low-latitude boundary layer (first uniquely identified using IMP 6 plasma and field observations by Eastman et al.). The magnetospheric boundary layer is the region of magnetosheath-like plasma located Earthward of, but generally contiguous with the magnetopause. This boundary layer is typically identified by comparing low-energy (less than 10 keV) ion spectra across the magnetopause. Low-energy electron measurements are also useful for identifying the boundary layer because the shocked solar wind or magnetosheath has a characteristic spectral signature for electrons as well. However, there are magnetopause crossings where low-energy electrons might suggest a depletion layer outside the magnetopause even though the traditional field-rotation signature indicates that this same region is a boundary layer Earthward of the current layer. The authors analyses avoided crossings which exhibit such ambiguities. Pristine magnetopause crossings are magnetopause crossings for which the current layer is well defined and for which there is no adjoining magnetospheric boundary layer as defined above. Although most magnetopause models to date apply to such crossings, few comparisons between such theory and observations of pristine magnetopause crossings have been made because most crossings have an associated magnetospheric boundary layer which significantly affects the applicable boundary conditions for the magnetopause current layer.

• Research Organization: Maryland Univ., Catonsville, MD (United States)
• OSTI ID: 42792
• Report Number(s): N--95-23184; NASA-CR--197391; NAS--1.26:197391; CNN: NAGW-1848
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
BOUNDARY LAYERS
ELECTRIC CURRENTS
MAGNETIC FIELDS
MAGNETOPAUSE
PROGRESS REPORT
SHEETS
SOLAR WIND