Ionospheric modification with obliquely incident waves: electron heating and parametric instabilities. Interim report, December 1983-March 1985

Technical Report · Tue Oct 01 04:00:00 EDT 1985

OSTI ID:6059898

Field, E C; Warber, C R

Nearly all ionospheric modification experiments have been carried out with the modifying wave at vertical incidence. For many applications, however, the modifying wave would probably be at oblique incidence. This report identifies nonlinear phenomena that could be caused by obliquely incident modifying waves. It concentrates on phenomena that might enhance or degrade the performance of high frequency (HF) radar or communications systems. The nonlinear processes that lead to ionospheric modification divide naturally into two categories: (1) ohmic heating, which alters temperature and hence, reaction rates, collision frequencies, and particle densities, and (2) generation of parametric instabilities, which causes a myriad of phenomena. As the incidence angle is increased, heating is affected by two competing trends. It is weakened by the increased path length, but is strengthened near caustics. A transmitter with a power-gain product on the order of 10 MW can launch and oblique wave strong enough to produce electric fields of several tenths of a volt per meter or more in the ionosphere. Such fields produce substantial temperature increases, which are initially concentrated near the caustics, but spread via heat conduction.

• Research Organization: Pacific-Sierra Research Corp., Los Angeles, CA (USA)
• OSTI ID: 6059898
• Report Number(s): AD-A-162603/5/XAB; PSR-1506
• Country of Publication: United States
• Language: English

Related Subjects

640201* -- Atmospheric Physics-- Auroral
Ionospheric
& Magetospheric Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
DENSITY
DIMENSIONS
EARTH ATMOSPHERE
ELECTRIC FIELDS
ELECTRONS
ELEMENTARY PARTICLES
FERMIONS
HEATING
INSTABILITY
IONOSPHERE
LENGTH
LEPTONS
MEASURING INSTRUMENTS
PARAMETRIC INSTABILITIES
PARTICLES
PHYSICAL PROPERTIES
PLANETARY IONOSPHERES
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
RADAR
RANGE FINDERS
THERMAL CONDUCTIVITY
THERMODYNAMIC PROPERTIES
WAVE PROPAGATION