Magnetic properties of the high-latitude tail boundary: Draping of magnetosheath field lines and tail-aligned current

Journal Article · Sat Jun 01 04:00:00 EDT 1991 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/91JA00570· OSTI ID:5256853

Ohtani, S ^[1]; Kokubun, S ^[2]

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1. Univ. of Tokyo (Japan) Johns Hopkins Univ., Laurel, MD (USA)
2. Univ. of Tokyo, (Japan)

Magnetic properties of the high-latitude tail boundary are examined with IMP 8 magnetometer data. The high-latitude tail boundary separates the tail lobe from the magnetosheath. Magnetic fields are stable in the tail lobe, but very irregular in the magnetosheath. Boundary crossings are marked by the rotation of magnetic components parallel to the boundary plane. The magnetic component normal to the boundary, if any, is very small in comparison to this rotational chnage. Despite large magnetic fluctuations in the magnetosheath, the magnetosheath-side field orientation is consistent with the draping of the interplanetary magnetic field (IMF) against the magnetotail. The boundary current has a component parallel to the lobe field (tail-aligned current), as well as a circumferential component. The IMF orientation controls the sheath-side B{sub y}, while the lobe-side field has a more rigid configuration flaring antisunward. Accordingly, the polarity of the tail-aligned current is primarily determined by the sign of IMF B{sub y}; in other words, the tail-aligned current shields the magnetotail against the IMF Y component. The current polarity is antisunward for positive IMF B{sub y} and sunward for negative IMF B{sub y} in the northern hemisphere. The tail-aligned current is also discussed in terms of the cusp (mantle) current system.

• OSTI ID: 5256853
• Journal Information: Journal of Geophysical Research; (United States), Journal Name: Journal of Geophysical Research; (United States) Vol. 96:A6; 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
COMPARATIVE EVALUATIONS
CURRENTS
EARTH ATMOSPHERE
EARTH MAGNETOSPHERE
ELECTRIC CURRENTS
EVALUATION
INTERACTIONS
INTERPLANETARY MAGNETIC FIELDS
LAYERS
MAGNETIC FIELDS
MAGNETIC PROPERTIES
MAGNETOSHEATH
MAGNETOTAIL
ORIENTATION
PHYSICAL PROPERTIES
SATELLITES
SOLAR ACTIVITY
SOLAR WIND