High-power high-frequency-induced Langmuir turbulence in the smooth ionosphere at Arecibo. II. Low duty cycle, altitude-resolved, observations

Journal Article · Thu Mar 01 04:00:00 EST 2001 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.1345704· OSTI ID:40205990

Cheung, P Y; Sulzer, M P; DuBois, D F; Russell, D A

This is the second of two papers comprising a theoretical and observational study of new, altitude-resolved, observations at Arecibo of Langmuir turbulence induced in the ionosphere by a new, more powerful, high frequency heater operated at very low duty cycles. Altitude resolution of 150 m in incoherent scatter radar spectra is made possible by the coded-long-pulse method. Here we present the first observation at Arecibo of the well-developed parametric decay instability and the Langmuir decay instability cascade features in the Thomson scatter radar power spectrum, of the plasma line, at the unmodified matching altitudes under near-cold start conditions. The dependence of the plasma line spectra on altitude, pump power, and density scale length have been studied. The temporal growth and saturation of the spectra during heating and the decay of the spectra in the afterglow of heating has also been studied in detail. Comparisons are made here with the theoretical predictions of the companion paper I [DuBois , Phys. Plasmas 8, 791 (2001)]. From these comparisons and a comparison with recent observations at both Arecibo and Tromso, we conclude that all the predictions of modern Langmuir turbulence theory for the radar spectral signatures of the turbulence in a smooth ionosphere have now been verified.

• Sponsoring Organization: (US)
• OSTI ID: 40205990
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 3 Vol. 8; ISSN 1070-664X
• Publisher: The American Physical Society
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AFTERGLOW
ALTITUDE
DECAY
DECAY INSTABILITY
HEATERS
HEATING
IONOSPHERE
RADAR
RESOLUTION
SATURATION
SPECTRA
TURBULENCE