Broadband VLF burst associated with ring current electrons

Journal Article · Mon Nov 01 04:00:00 EST 1982 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JA087iA11p09120· OSTI ID:6573841

Maeda, K; Anderson, R R

During the periods after the maximum phase of geomagnetic storms on 2 April 1972 a broadband VLF emission burst has been observed by the equatorially orbiting satellit S/sup 3/-A (Explorer 45) along its inbound plasmapause crossings. The frequency band broadening takes place just outside of the nighttime plasmasphere, where the density of cold plasma has been known to be very low during the later phase of a geomagnetic storm. Instead of the gradual broadening of several hours duration, a burst type braodening of VLF emission lasting less than ten minutes was observed in the similar location. The magnetic field component of this emission is very weak and the frequency spreads below the local half electron cyclotron frequency. Corresponding enhancement of the anisotropic ring-current electrons is also very sudden and limited below the order of 10 keV without significant velocity dispersion, in contrast to the gradual broadening events. The cause of this type of emission band spreading can be attributed to the generation of the quasi-electrostatic whistler mode emissions of short wavelength by hot bi-maxwellian electrons surging into the domain of relatively low density magnetized cold plasma. The lack of energy dispersion in the enhanced electrons indicates that the inner edge of the plasma sheet, the source of these hot electrons, is not far from the location of this event.

• Research Organization: Laboratory for Planetary Atmospheres, NASA/GSFC, Greenbelt, Maryland 20771
• OSTI ID: 6573841
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Journal Issue: A11 Vol. 87:A11; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

640203* -- Atmospheric Physics-- Magnetospheric Phenomena-- (-1987)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CURRENTS
CYCLOTRON FREQUENCY
EARTH ATMOSPHERE
ELECTRIC CURRENTS
ELECTRIC FIELDS
ELECTROMAGNETIC RADIATION
EXPLORER SATELLITES
MAGNETIC FIELDS
MAGNETOSPHERE
PLASMA DENSITY
PLASMAPAUSE
RADIATIONS
RADIOWAVE RADIATION
RING CURRENTS
SATELLITES