The angular distribution of auroral kilometric radiation. Progress report

Technical Report · Sun Aug 01 04:00:00 EDT 1976

OSTI ID:7317141

Green, J L; Gurnett, D A; Shawhan, S D

Measurements of the angular distribution of auroral kilometric radiation (AKR) are presented using observations from the Hawkeye 1, IMP 6, and IMP 8 satellites. The wave experiments on Hawkeye 1 and IMP 6 provide electric field measurements of AKR in narrow frequency bands centered at 178, 100, and 56.2 kHz and IMP 8 provides measurements at 500 kHz. From a frequency of occurrence survey, at satellite radial distances greater than 7 Re (earth radii) it is shown that AKR is preferentially and instantaneously being beamed into solid angles of approximately 3.5 steradians at 178 kHz, 1.8 steradians at 100 kHz, and 1.1 steradians at 56.2 kHz, directed upward from the night time auroral zones. Simultaneous multiple satellite observations of AKR in the northern hemisphere show that the radiation occurs simultaneously throughout these solid angles and that the topside plasmapause acts as an abrupt propagation cutoff on the nigh side of the earth. On the day side of the earth this abrupt cutoff at the plasmapause is not observed. The results of a computer ray tracing model qualitatively describing the propagation characteristics of AKR are also discussed.

• Research Organization: Iowa Univ., Iowa City (USA). Dept. of Physics and Astronomy
• OSTI ID: 7317141
• Report Number(s): AD-A-033218
• Country of Publication: United States
• Language: English

Related Subjects

640201* -- Atmospheric Physics-- Auroral
Ionospheric
& Magetospheric Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ANGULAR DISTRIBUTION
AURORAE
DISTRIBUTION
ELECTRIC FIELDS
ELECTROMAGNETIC RADIATION
FREQUENCY RANGE
KHZ RANGE
LONG WAVE RADIATION
PLASMAPAUSE
RADIATIONS
RADIOWAVE RADIATION
WAVE PROPAGATION