Ionospheric heating with oblique HF waves

Technical Report · Mon Oct 01 04:00:00 EDT 1990

OSTI ID:7262048

Field, E C; Bloom, R M

This paper presents calculations of ionospheric electron density perturbations and ground-level signal changes produced by intense oblique high-frequency (HF) transmitters. Our analysis takes into account radio field focusing at caustics, the consequent joule-heating of the surrounding plasma, heat conduction, diffusion, and recombination processes--these being the effects of a powerful oblique modifying, wave. It neglects whatever plasma instabilities might occur. We then seek effects on a secondary 'test wave that is propagated along the same path as the first. Our calculations predict ground-level field-strength reductions of several dB in the test wave for modifying waves having ERP in the 85-to-90 dBW range. These field-strength changes are similar in sign, magnitude, and location to ones measured in Soviet experiments. Our results are sensitive to the the model ionosphere assumed, so future experiments should employ the widest possible range of frequencies and propagation conditions. An effective power of 90 dBW seems to be a sort of threshold that, if exceeded, results in substantial rather than small signal changes. Our conclusions are based solely on joule-heating and subsequent defocusing of waves passing through caustic regions.

• Research Organization: Pacific-Sierra Research Corp., Los Angeles, CA (United States)
• OSTI ID: 7262048
• Report Number(s): AD-P-006504/5/XAB
• Country of Publication: United States
• Language: English

Related Subjects

661320* -- Auroral
Ionospheric
& Magnetospheric Phenomena-- (1992-)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
DIFFUSION
DISTURBANCES
EARTH ATMOSPHERE
ELECTRIC HEATING
ELECTRON DENSITY
FOCUSING
GROUND LEVEL
HEATING
HIGH-FREQUENCY HEATING
INSTABILITY
IONOSPHERE
JOULE HEATING
LEVELS
PLANETARY IONOSPHERES
PLASMA HEATING
PLASMA INSTABILITY
RESISTANCE HEATING
WAVE PROPAGATION