Plasma instabilities stimulated by HF transmitters in space
Article first published online: 7 DEC 2012
This paper is not subject to U.S. copyright. Published in 1988 by the American Geophysical Union.
Volume 23, Issue 4, pages 585–590, July-August 1988
How to Cite
1988), Plasma instabilities stimulated by HF transmitters in space, Radio Sci., 23(4), 585–590, doi:10.1029/RS023i004p00585., and (
- Issue published online: 7 DEC 2012
- Article first published online: 7 DEC 2012
- Manuscript Accepted: 13 JAN 1988
- Manuscript Received: 24 SEP 1987
Diffuse incoherent signal returns are often observed on Alouette and ISIS topside ionograms in addition to coherent echoes of electromagnetic and electrostatic waves. These diffuse signals, which at times can be the dominant features on topside ionograms, have been attributed to sounder-induced temperature anisotropies which drive the Harris instability. Previous theoretical investigations were based on the electrostatic approximation to the dispersion equation. The present paper will present calculations indicating that when the electromagnetic terms are retained in the dispersion equation and when the sounder-stimulated perpendicular electron temperature approaches 1 keV, then the whistler mode can have a temporal growth rate larger than the electrostatic electron cyclotron harmonic wave mode central to the diffuse resonance problem. Present sounders lack the power and antenna lengths to generate whistler mode waves in this manner. In addition, such waves would have large group velocities and would quickly leave the vicinity of the sounder. Experiments to investigate the wave growth, propagation, and damping of such stimulated waves are planned for the 1990s using a highly flexible sounder on the space shuttle and a receiver on a subsatellite.