Different phases of a magnetospheric substorm on June 23, 1979

Journal Article · Wed Jul 01 00:00:00 EDT 1987 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JA092iA07p07443· OSTI ID:6288734

Tanskanen, P; Kangas, J; Block, L; Kremser, G; Korth, A; Woch, J; Iversen, I B; Torkar, K M; Riedler, W; Ullaland, S; others, and

A detailed case study was carried out of a magnetospheric substorm on June 23, 1979. Satellite, balloon and ground based particle and field data were used to correlate observations covering an extended area both in longitude and in latitude. The loading phase of the substorm was characterized by an equatorward convex, southward moving precipitation boundary. During the equatorward motion a hardening of the electron spectrum is seen. We show that betatron acceleration is stronger than Fermi acceleration for earthward convecting particles in a dipolelike field, and that the reverse is true for a taillike field. It is argued that the observed precipitation front represents an ionospheric mapping of an injection boundary. Energy dependent increases of the ion phase space density during the loading phase can be explained in terms of an earthward displacement of the inner edge of the neutral sheet current. Pi 2 pulsation on the satellite and on the ground are present both at substorm onset and at subsequent intensifications. Evidence is given for plausible correlation between changes in the IMF and variations in ionospheric electric fields as observed on balloons. It is suggested that changes of the IMF and variations in ionospheric electric fields as observed on balloons. It is suggested that changes of the IMF from south to north may have triggered the substorm and expansion phase intensifications. copyright American Geophysical Union 1987

• Research Organization: Department of Physics, University of Oulu, Finland; and Max-Planck-Institut fuer Aeronomie, Katlenburg-Lindau, Federal Republic of Germany
• OSTI ID: 6288734
• Journal Information: J. Geophys. Res.; (United States), Vol. 92:A7
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
MAGNETIC BAYS
CHARGED-PARTICLE PRECIPITATION
AURORAE
ELECTRIC FIELDS
GEOMAGNETIC CONJUGACY
INTERPLANETARY MAGNETIC FIELDS
ION DENSITY
IONOSPHERE
EARTH ATMOSPHERE
MAGNETIC FIELDS
PLANETARY IONOSPHERES
640201* - Atmospheric Physics- Auroral
Ionospheric
& Magetospheric Phenomena