scholarly journals Phase coupling in Langmuir wave packets: Evidence of four wave interactions in solar type III radio bursts

2012 ◽  
Vol 39 (5) ◽  
pp. n/a-n/a ◽  
Author(s):  
G. Thejappa ◽  
R. J. MacDowall ◽  
M. Bergamo
Keyword(s):  
Wave Packets ◽  
Langmuir Wave ◽  
Radio Bursts ◽  
Phase Coupling ◽  
Wave Interactions ◽  
Type Iii ◽  
Solar Type

Ulysses Observations of Nonlinear Wave-wave Interactions in the Source Regions of Type III Solar Radio Bursts

2000 ◽  
Vol 179 ◽  
pp. 447-450
Author(s):  
G. Thejappa ◽  
R. J. MacDowall
Keyword(s):  
Acoustic Waves ◽  
Modulational Instability ◽  
Langmuir Wave ◽  
Wave Interactions ◽  
Burst Source ◽  
Langmuir Waves ◽  
Type Iii ◽  
Source Regions ◽  
Ion Acoustic ◽  
Solar Type

AbstractThe Ulysses Unified Radio and Plasma Wave Experiment (URAP) has observed Langmuir, ion-acoustic and associated solar type III radio emissions in the interplanetary medium. Bursts of 50–300 Hz (in the spacecraft frame) electric field signals, corresponding to long-wavelength ion-acoustic waves are often observed coincident in time with the most intense Langmuir wave spikes, providing evidence for the electrostatic decay instability. Langmuir waves often occur as envelope solitons, suggesting that strong turbulence processes, such as modulational instability and soliton formation, often coexist with weak turbulence processes, such as electrostatic decay, in a few type III burst source regions.

Evidence for nonlinear wave-wave interactions in solar type III radio bursts

1986 ◽  
Vol 308 ◽  
pp. 954 ◽  
Author(s):  
R. P. Lin ◽  
W. K. Levedahl ◽  
W. Lotko ◽  
D. A. Gurnett ◽  
F. L. Scarf
Keyword(s):  
Nonlinear Wave ◽  
Radio Bursts ◽  
Wave Interactions ◽  
Type Iii ◽  
Solar Type

scholarly journals Evidence for four- and three-wave interactions in solar type III radio emissions

2013 ◽  
Vol 31 (8) ◽  
pp. 1417-1428 ◽  
Author(s):  
G. Thejappa ◽  
R. J. MacDowall ◽  
M. Bergamo
Keyword(s):  
Wave Packet ◽  
Second Harmonic ◽  
Wave Packets ◽  
Spectral Peak ◽  
Wave Number ◽  
Radio Bursts ◽  
Langmuir Waves ◽  
Type Iii ◽  
Primary Peak ◽  
Solar Type

Abstract. The high time resolution observations obtained by the STEREO/WAVES experiment show that in the source regions of solar type III radio bursts, Langmuir waves often occur as intense localized wave packets with short durations of only few ms. One of these wave packets shows that it is a three-dimensional field structure with WLneTe ~ 10−3, where WL is the peak energy density, and ne and Te are the electron density and temperature, respectively. For this wave packet, the conditions of the oscillating two-stream instability (OTSI) and supersonic collapse are satisfied within the error range of determination of main parameters. The density cavity, observed during this wave packet indicates that its depth, width and temporal coincidence are consistent with those of a caviton, generated by the ponderomotive force of the collapsing wave packet. The spectrum of each of the parallel and perpendicular components of the wave packet contains a primary peak at fpe, two secondary peaks at fpe ± fS and a low-frequency enhancement below fS, which, as indicated by the frequency and wave number resonance conditions, and the fast Fourier transform (FFT)-based tricoherence spectral peak at (fpe, fpe, fpe + fS, fpe − fS), are coupled to each other by the OTSI type of four-wave interaction (fpe is the local electron plasma frequency and fS is the frequency of ion sound waves). In addition to the primary peak at fpe, each of these spectra also contains a peak at 2fpe, which as indicated by the frequency and wave number resonance conditions, and the wavelet-based bicoherence spectral peak at (fpe, fpe), appears to correspond to the second harmonic electromagnetic waves generated as a result of coalescence of oppositely propagating sidebands excited by the OTSI. Thus, these observations for the first time provide combined evidence that (1) the OTSI and related strong turbulence processes play a significant role in the stabilization of the electron beam, (2) the coalescence of the oppositely propagating up- and down-shifted daughter Langmuir waves excited by the OTSI probably is the emission mechanism of the second harmonic radiation, and (3) the Langmuir collapse follows the route of OTSI in some of the type III radio bursts.

Phase coupling in Langmuir wave packets: Possible evidence of three-wave interactions in the upstream solar wind

1996 ◽  
Vol 23 (1) ◽  
pp. 109-112 ◽  
Author(s):  
S. D. Bale ◽  
D. Burgess ◽  
P. J. Kellogg ◽  
K. Goetz ◽  
R. L. Howard ◽  
...  
Keyword(s):  
Solar Wind ◽  
Wave Packets ◽  
Langmuir Wave ◽  
Phase Coupling ◽  
Wave Interactions ◽  
Upstream Solar Wind

WindSpacecraft Observations of Solar Impulsive Electron Events Associated with Solar Type III Radio Bursts

1998 ◽  
Vol 503 (1) ◽  
pp. 435-445 ◽  
Author(s):  
R. E. Ergun ◽  
D. Larson ◽  
R. P. Lin ◽  
J. P. McFadden ◽  
C. W. Carlson ◽  
...  
Keyword(s):  
Radio Bursts ◽  
Type Iii ◽  
Solar Type
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