Large scale response of the magnetosphere to a southward turning of the interplanetary magnetic field

Journal Article · Sun Mar 01 04:00:00 EST 1987 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/JA092iA03p02365· OSTI ID:5510747

Sauvaud, J A; Treilhou, J P; Saint-Marc, A; Dandouras, J; Reme, H ^[1]; Korth, A; Kremser, G ^[2]; Parks, G K ^[3]; Zaitzev, A N; Petrov, V ^[4]; Lazutine, L ^[5]; Pellinen, R ^[6]

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1. Toulouse-3 Univ., 31 (France)
2. Max-Planck-Inst. fuer Aeronomie, Katlenburg-Lindau (West Germany)
3. Univ. of Washington, Seattle (United States)
4. USSR Academy of Sciences, Moscow (USSR)
5. Polar Geophysical Inst., Apatity (USSR)
6. Finnish Meteorological Inst., Helsinki (Finland)

A set of coordinated measurements obtained on March 4, 1979, in the solar wind, in the magnetotail, at geostationary orbit, in the auroral ionosphere and on the ground allowed a detailed study of the overall magnetospheric response to a southward turning of the interplanetary magnetic field. this study shows that the magnetosphere responds without any appreciable delay to the change of the interplanetary magnetic field (IMF) direction. The intensity of the electrojets increases, and both westward electrojet and auroral forms move southward in the night sector. The magnetic field topology in the inner nightside magnetosphere (6.6 R{sub E}) becomes increasingly taillike, inducing the adiabatic earthward motion of the high-energy electrons and the precipitation of those with small equatorial pitch angles. All these events coincide with the increase of the solar wind-magnetosphere energy coupling function {var epsilon}. The large set of available data shows that a series of weak, short-lived substorms sporadically occurs during the period of southward directed IMF, before the main substorm onset. Finally a well-defined substorm occurs about 80 min after the IMF reversal and during the southward IMF episode. Magnetic and auroral activity increases again when the IMF begins to turn northward and subsides as soon as the IMF B{sub z} component reaches positive values.

• OSTI ID: 5510747
• Journal Information: Journal of Geophysical Research; (United States), Journal Name: Journal of Geophysical Research; (United States) Vol. 92:A3; ISSN 0148-0227; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

661320* -- Auroral
Ionospheric
& Magnetospheric Phenomena-- (1992-)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ADIABATIC PROCESSES
AURORAL ZONES
CHARGED-PARTICLE PRECIPITATION
EARTH ATMOSPHERE
EARTH MAGNETOSPHERE
ELECTRON PRECIPITATION
ENERGY LOSSES
FUNCTIONS
INTERACTIONS
INTERPLANETARY MAGNETIC FIELDS
IONOSPHERE
LOSSES
MAGNETIC BAYS
MAGNETIC FIELD CONFIGURATIONS
MAGNETIC FIELDS
MAGNETOTAIL
MATHEMATICS
ORIENTATION
PLANETARY IONOSPHERES
RESPONSE FUNCTIONS
SOLAR ACTIVITY
SOLAR WIND
TOPOLOGY