Characterization of the IMF B[sub y]-dependent field-aligned currents in the cleft region based on DE 2 observations

Journal Article · Mon Feb 01 04:00:00 EST 1993 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/92JA01014· OSTI ID:6820787

Taguchi, S ^[1]; Sugiura, M ^[2]; Winningham, J D ^[3]; Slavin, J A ^[4]

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1. Kyoto Univ. (Japan)
2. Tokai Univ., Tokyo (Japan)
3. Southwest Research Institute, San Antonio, TX (United States)
4. NASA Goddard Space Flight Center, Greenbelt, MD (United States)

The interplanetary magnetic field (IMF) B[sub y]-dependent distribution of field-aligned currents in the cleft region is studied, using the magnetic field and plasma data from 47 passes of Dynamics Explorer (DE) 2. These orbits were chosen on the conditions that cusp/cleft particles are detected and that at the same time the IMF B[sub y] and B[sub z] components satisfy the criteria [vert bar]B[sub y][vert bar][ge]5 nT and [vert bar]B[sub z][vert bar][le]5 nT during the satellite's crossing of the relevant field-aligned current region. These B[sub y]-dependent field-aligned currents in the equatorward and the poleward sheets are referred to as the low-latitude cleft current (LCD) and the high-latitude cleft current (HCC), respectively. The cusp/cleft electron precipitation region and the LCD region overlap with each other to a varying degree irrespective of the sign of B[sup y]. For positive (negative) B[sub y], LCD has the same direction as the morning (afternoon) region 1 current or the afternoon (morning) region 2 current. The authors argue that the LCD region is not an extension of the region 1 or region 2 current system and that a pair of LCD and HCC constitutes the cleft field-aligned current regime. The proposed pair of cleft field-aligned currents is explained with a qualitative model in which this pair of currents is generated on the open field lines that have just been reconnected on the dayside magnetopause. The model assumes a quasi-steady reconnection operating within certain longitudinal width extending to both sides of the stagnation point on the dayside magnetopause. 49 refs., 10 figs.

• OSTI ID: 6820787
• Journal Information: Journal of Geophysical Research; (United States), Journal Name: Journal of Geophysical Research; (United States) Vol. 98:A2; ISSN JGREA2; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

661320* -- Auroral
Ionospheric
& Magnetospheric Phenomena-- (1992-)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CHARGED-PARTICLE PRECIPITATION
CURRENTS
DISTRIBUTION
DISTURBANCES
DYNAMICS
EARTH ATMOSPHERE
ELECTRIC CURRENTS
ELECTRIC FIELDS
ELECTRON PRECIPITATION
INTERPLANETARY MAGNETIC FIELDS
IONOSPHERE
MAGNETIC FIELDS
MAGNETIC RECONNECTION
MAGNETOPAUSE
MAGNETOSHEATH
MECHANICS
PLANETARY IONOSPHERES
PLASMA
PLASMA DRIFT
STAGNATION POINT