UHF radar-backscatter enhancements from the topside ionosphere

Technical Report · Thu May 03 04:00:00 EDT 1990

OSTI ID:6389257

Groves, K M; Lee, M C; Foster, J C

Intense (about 20 dB) enhancements of the incoherent radar backscatter spectrum from the topside ionosphere have been observed with the Millstone Hill UHF radar; enhancements occurring at the local ion acoustic frequency causing large asymmetries in the measured ion line may be produced by current-driven instabilities. In addition to current-driven processes, we propose the generation of intense ion acoustic turbulence by the nonlinear interaction of Langmuir waves in the ionosphere. Qualitatively, an enhanced Langmuir wave spectrum is produced by the action of suprathermal electrons associated with field-aligned currents. Energy from the enhanced Langmuir waves can then be coupled into ion acoustic models through nonlinear processes. The resulting amplification of the ion modes can be detected by incoherent scatter radars. Analytical and numerical calculations describing the above processes quantitatively will be presented. This newly observed phenomenon is associated with intriguing ionospheric plasma processes. The induced plasma modes have large radar cross-sections give rise to strong backscatter radar echoes. Hence, in the past, they were probably misidentified to be satellite radar returns. From the point of view of space surveillance, it is desirable to identify potential geophysical processes leading to false satellite signals.

• Research Organization: Massachusetts Inst. of Tech., Cambridge, MA (United States). Plasma Fusion Center
• OSTI ID: 6389257
• Report Number(s): AD-P-006293/5/XAB
• Country of Publication: United States
• Language: English

Related Subjects

661320* -- Auroral
Ionospheric
& Magnetospheric Phenomena-- (1992-)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AMPLIFICATION
ANALYTICAL SOLUTION
BACKSCATTERING
CROSS SECTIONS
CURRENTS
EARTH ATMOSPHERE
ELECTRIC CURRENTS
ELECTRONS
ELEMENTARY PARTICLES
FERMIONS
INCOHERENT SCATTERING
INSTABILITY
ION ACOUSTIC WAVES
ION WAVES
IONOSPHERE
LEPTONS
MEASURING INSTRUMENTS
NUMERICAL SOLUTION
PLANETARY IONOSPHERES
PLASMA INSTABILITY
PLASMA WAVES
RADAR
RANGE FINDERS
REFLECTION
SCATTERING
SURVEILLANCE