Mode coupling of the two‐plasmon decay instability to ion‐acoustic waves and the effect on (3/2)‐harmonic emission

1992 ◽  
Vol 4 (9) ◽  
pp. 2934-2941 ◽  
Author(s):  
Jochen Meyer
Keyword(s):  
Acoustic Waves ◽  
Mode Coupling ◽  
Ion Acoustic Waves ◽  
Decay Instability ◽  
Harmonic Emission ◽  
Ion Acoustic

First Observation of Ion Acoustic Waves Produced by the Langmuir Decay Instability

2000 ◽  
Vol 84 (13) ◽  
pp. 2869-2872 ◽  
Author(s):  
S. Depierreux ◽  
J. Fuchs ◽  
C. Labaune ◽  
A. Michard ◽  
H. A. Baldis ◽  
...  
Keyword(s):  
Acoustic Waves ◽  
Ion Acoustic Waves ◽  
Decay Instability ◽  
Ion Acoustic ◽  
Langmuir Decay

scholarly journals High time resolution PFISR and optical observations of naturally enhanced ion acoustic lines

2009 ◽  
Vol 27 (4) ◽  
pp. 1457-1467 ◽  
Author(s):  
R. G. Michell ◽  
K. A. Lynch ◽  
C. J. Heinselman ◽  
H. C. Stenbaek-Nielsen
Keyword(s):  
High Resolution ◽  
Time Resolution ◽  
Acoustic Waves ◽  
Fast Moving ◽  
High Time ◽  
High Time Resolution ◽  
Ion Acoustic Waves ◽  
Raw Data ◽  
Ion Acoustic ◽  
Auroral Imaging

Abstract. Observations of naturally enhanced ion acoustic lines (NEIALs) taken with the Poker Flat Incoherent Scatter Radar (PFISR) using a mode with very high time resolution are presented. The auroral event took place over Poker Flat, Alaska on 8 February 2007 at 09:35 UT (~22:00 MLT), and the radar data are complemented by common-volume high-resolution auroral imaging. The NEIALs occurred during only one of the standard 15-s integration periods. The raw data of this time show very intermittent NEIALs which occur only during a few very short time intervals (≤1 s) within the 15-s period. The time sampling of the raw data, ~19 ms on average, allows study of the time development of the NEIALs, though there are indications that even finer time resolution would be of interest. The analysis is based on the assumption that the NEIAL returns are the result of Bragg scattering from ion-acoustic waves that have been enhanced significantly above thermal levels. The spectra of the raw data indicate that although the up- and down-shifted shoulders can both become enhanced at the same time, (within 19 ms), they are most often enhanced individually. The overall power in the up-and down-shifted shoulders is approximately equal throughout the event, with the exception of one time, when very large up-shifted power was observed with no corresponding down-shifted power. This indicates that during the 480 μs pulse, the strongly enhanced ion-acoustic waves were only traveling downward and not upward. The exact time that the NEIALs occurred was when the radar beam was on the boundary of a fast-moving (~10 km/s), bright auroral structure, as seen in the high resolution auroral imaging of the magnetic zenith. When viewed with high time resolution, the occurrence of NEIALs is associated with rapid changes in auroral luminosity within the radar field of view due to fast-moving auroral fine structures.

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