ISEE-1 and -2 observations of an isolated diamagnetic event: An earthward-moving plasma bulge or a tail-aligned flux rope

Journal Article · Fri Sep 04 04:00:00 EDT 1992 · Geophysical Research Letters (American Geophysical Union); (United States)

DOI:https://doi.org/10.1029/92GL01805· OSTI ID:5173313

Ohtani, S ^[1]; Elphic, R C ^[2]; Russell, C T ^[3]; Kokubun, S ^[4]

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1. Johns Hopkins Univ., Laurel, MD (United States) Univ. of Tokyo (Japan)
2. Los Alamos National Lab., NM (United States)
3. Univ. of California, Los Angeles, CA (United States)
4. Univ. of Tokyo (Japan)

This paper reports a transient strong diamagnetic event observed with the ISEE-1 and -2 spacecraft in the near-Earth magnetotail. Magnetic signatures associated with the event resemble those of flux rope events found in the distant magnetotail. The present event should be distinguished from those in several previous reports based on the following points: (1) The event is observed in the near-Earth tail (X [approximately][minus]17 R[sub E]), not in the distant tail. (2) The tail field changes from a stressed configuration to a more dipolar one in the course of the event, and the plasma data suggest that the heating and the resultant expansion of the plasma take place simultaneously. (3) The minimum of the magnetic field strength B[sub T] is [approximately]1 nT; such a strong depression is rarely observed in the near-Earth tail. (4) An earthward plasma jet (300 to 500 km/s) continues for about 3 min, including a period of very weak magnetic field; the duration of the jet is exceptionally long compared to previously reported high-speed flows in the plasma sheet. These magnetic field and plasma signatures are discussed in terms of two models: an earthward-moving plasma bulge and a tail-aligned flux rope. 16 refs., 4 figs.

• OSTI ID: 5173313
• Journal Information: Geophysical Research Letters (American Geophysical Union); (United States), Journal Name: Geophysical Research Letters (American Geophysical Union); (United States) Vol. 19:17; ISSN GPRLAJ; ISSN 0094-8276
• Country of Publication: United States
• Language: English

Related Subjects

661320* -- Auroral
Ionospheric
& Magnetospheric Phenomena-- (1992-)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
DIAMAGNETISM
DISTURBANCES
EARTH ATMOSPHERE
EARTH MAGNETOSPHERE
MAGNETIC FLUX
MAGNETISM
MAGNETOTAIL
PLASMA DIAMAGNETISM
TRANSIENTS