The lower subsidiary diffuse plasma resonances and the classification of radio emissions below the plasma frequency
- NASA Goddard Space Flight Center, Greenbelt, MD (United States)
The diffuse ionospheric resonances D{sub n}, stimulated by topside sounders, have been studied for over 2 decades. These resonances are observed below the plasma frequency f{sub N} between the harmonics of the electron gyrofrequency f{sub H}. The D{sub n} resonances are often accompanied by upper and lower subsidiary branches. The present paper concentrates on the classification of diffuse resonances, one motivation being the possible application to the interpretation of naturally occurring radio emissions in the magnetosphere. Osherovich has shown that the D{sub n} resonances are characterized by a nonequally spaced spectrum of frequencies f{sub D{sub n}} = f{sub Ds}n{sup 1/2} (n = 1, 2, 3, and 4), where f{sub D{sub s}} = 0.95(f{sub N}f{sub H}){sup 1/2}, and that the upper subsidiary resonances D{sub n}{sup +} = (f{sup 2}{sub D{sub n}} + f{sup 2}{sub H}){sup 1/2}. This classification is here extended to include the lower subsidiary resonances D{sub n}{sup minus} (n = 1, 2, 3, and 4), and it is shown that their frequencies are related to f{sub D{sub n}} and f{sub H} by the expression f{sub D{sub n}} = (f{sup 2}{sub D{sub n}} - f{sup 2}{sub H}){sup 1/2}. This result is based on a combination of previously published data and newly scaled ionograms from the Alouette 2 and ISIS 1 topside sounder experiments.
- OSTI ID:
- 5812770
- Journal Information:
- Journal of Geophysical Research; (United States), Vol. 96:A11; ISSN 0148-0227
- Country of Publication:
- United States
- Language:
- English
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GENERAL PHYSICS
IONOSPHERE
PLASMA WAVES
CLASSIFICATION
EARTH MAGNETOSPHERE
ELECTRON DENSITY
LANGMUIR FREQUENCY
RADIOWAVE RADIATION
RESONANCE
SATELLITES
EARTH ATMOSPHERE
ELECTROMAGNETIC RADIATION
PLANETARY IONOSPHERES
RADIATIONS
661320* - Auroral
Ionospheric
& Magnetospheric Phenomena- (1992-)