Observations of a free-energy source for intense electrostatic waves

Journal Article · Thu May 01 04:00:00 EDT 1980 · Geophys. Res. Lett.; (United States)

DOI:https://doi.org/10.1029/GL007i005p00293· OSTI ID:5365260

Kurth, W S; Frank, L A; Gurnett, D A; Burek, B G; Ashour-Abdalla, M

Significant progress has been made in understanding intense electrostatic waves near the upper hybrid resonance frequency in terms of the theory of multiharmonic cyclotron emissions using a classical loss-cone distribution function as a model. Recent observations by Hawkeye 1 and GEOS 1 have verified the existence of loss-cone distributions in association with the intense electrostatic wave events, however, other observations by Hawkeye and ISEE have indicated that loss cones are not always observable during the wave events, and in fact other forms of free energy may also be responsible for the instability. Now, for the first time, a positively sloped feature in the perpendicular distribution function has been uniquely identified with intense electrostatic wave activity. Correspondingly, we suggest that the theory is flexible under substantial modifications of the model distribution function.

• Research Organization: Department of Physics and Astronomy, The University of Iowa, Iowa City, IA 52242
• OSTI ID: 5365260
• Journal Information: Geophys. Res. Lett.; (United States), Journal Name: Geophys. Res. Lett.; (United States) Vol. 7:5; ISSN GPRLA
• Country of Publication: United States
• Language: English

Related Subjects

640203* -- Atmospheric Physics-- Magnetospheric Phenomena-- (-1987)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
DISTRIBUTION FUNCTIONS
EARTH ATMOSPHERE
ENERGY
FREE ENERGY
LOSS CONE
MAGNETOSPHERE
PHYSICAL PROPERTIES
PLASMA WAVES
THERMODYNAMIC PROPERTIES