Dayside auroral activity and magnetic flux transfer from the solar wind

Journal Article · Sun Jan 01 04:00:00 EST 1989 · Geophysical Research Letters (American Geophysical Union); (USA)

DOI:https://doi.org/10.1029/GL016i001p00033· OSTI ID:5716571

Lockwood, M ^[1]; Sandholt, P E ^[2]; Cowley, S W.H. ^[3]

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1. Rutherford Appleton Laboratory, Chilton (England)
2. Univ. of Oslo (Norway)
3. Imperial College, London (England)

Combined observations by meridian-scanning photometers and the EISCAT radar show that the midday-auroral breakup phenomenon is associated with major increases in ionospheric flow. A sequence of nine events is observed in the early afternoon MLT sector during a period when the IMF is strongly southward with a large positive B{sub y} component. Each auroral structure is seen at both 630 and 557.7nm and initially moves westward, accompanied by an increase in potential of 30-60kV across the north-south dimension of the EISCAT field-of-view. After a few minutes the arc (or arc fragment) moves into the polar cap and fades, and the velocities observed by the radar swing from westward toward northward. The authors conclude that dayside auroral breakup is closely associated with momentum transfer across the magnetopause which occurs in a series of events 5-15 minutes apart. The largest of the observed events has dimensions of about 300km (in the direction of westward motion) by 700km, is bounded on its poleward edge by a 5kR arc and is associated with a potential of at least 80kV.

• OSTI ID: 5716571
• Journal Information: Geophysical Research Letters (American Geophysical Union); (USA), Journal Name: Geophysical Research Letters (American Geophysical Union); (USA) Vol. 16:1; ISSN 0094-8276; ISSN GPRLA
• Country of Publication: United States
• Language: English

Related Subjects

640201* -- Atmospheric Physics-- Auroral
Ionospheric
& Magetospheric Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AURORAE
EARTH ATMOSPHERE
EARTH MAGNETOSPHERE
INTERACTIONS
INTERPLANETARY MAGNETIC FIELDS
IONOSPHERE
MAGNETIC FIELDS
MAGNETIC FLUX
MAGNETOPAUSE
MEASURING INSTRUMENTS
MOMENTUM TRANSFER
PHOTOMETERS
PLANETARY IONOSPHERES
POLAR REGIONS
RADAR
RANGE FINDERS
SOLAR ACTIVITY
SOLAR WIND