Auroral electrodynamics at the cusp/cleft poleward boundary during northward interplanetary magnetic field

Journal Article · Wed May 01 00:00:00 EDT 1991 · Geophysical Research Letters (American Geophysical Union); (United States)

DOI:https://doi.org/10.1029/91GL00849· OSTI ID:5221360

Sandholt, P E ^[1]

---

1. Univ. of Oslo (Norway)

Combined latitude profiles of optical aurora, magnetic disturbances, particle precipitation and field-aligned currents are used to investigate the electrodynamics of the cusp/cleft ionosphere during northward interplanetary magnetic field. An active zone of strong azimuthal plasma convection, manifested by the Svalgaard-Mansurov effect in ground magnetic deflections and auroral structure at the poleward boundary of the cusp/cleft is observed within {approximately}1,030-1,230 MLT. Contrary to the typical cusp/cleft auroral activity during negative IMF B{sub z} the discrete auroral forms in the present case move into the cusp/cleft arc, from the poleward edge. Both the optical observations and the inferred field-aligned current/plasma flow pattern indicate a generator mechanism poleward of the cusp/cleft, giving rise to strong momentum transfer and discrete electron precipitation within a {approximately}200 km wide latitudinal zone at the cusp/cleft poleward boundary, at the time of a poleward moving cusp/cleft arc. From this and other similar studies of the cusp/cleft ionosphere, the author concludes that a qualitatively similar mode of solar wind-magnetosphere interaction is operating both during northward and southward IMF.

• OSTI ID: 5221360
• Journal Information: Geophysical Research Letters (American Geophysical Union); (United States), Vol. 18:5; ISSN 0094-8276
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
POLAR CUSP
ELECTRODYNAMICS
AURORAE
CHARGED-PARTICLE PRECIPITATION
CONVECTION
DATA
ELECTRIC CURRENTS
INTERACTIONS
INTERPLANETARY MAGNETIC FIELDS
IONOSPHERE
MOMENTUM TRANSFER
ORIENTATION
PLASMA DRIFT
SOLAR WIND
CURRENTS
EARTH ATMOSPHERE
ENERGY TRANSFER
HEAT TRANSFER
INFORMATION
MAGNETIC FIELDS
MASS TRANSFER
PLANETARY IONOSPHERES
SOLAR ACTIVITY
640201* - Atmospheric Physics- Auroral
Ionospheric
& Magetospheric Phenomena