The intrinsic relation between envelope solitons and plasma instabilities

A general form of the one-dimensional nonlinear Schrödinger equation is derived; the coefficients depend mainly on the linear dispersion relation, as does the nonlinear term. Envelope solitons may only exist together with some plasma instabilities. An example of solar radio bursts is selected as evidence for envelope solitons in the electromagnetic waveband.

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The Theory of Solar Radio Bursts: Can it be understood by the Non-Expert?

Publications of the Astronomical Society of Australia ◽

10.1017/s1323358000016180 ◽

1981 ◽

Vol 4 (2) ◽

pp. 139-144 ◽

Cited By ~ 1

Author(s):

D. B. Melrose

Keyword(s):

Observational Data ◽

Solar Radio ◽

Solar Physics ◽

Plasma Instabilities ◽

The Sun ◽

Radio Bursts ◽

Wave Interactions ◽

Solar Radio Bursts ◽

Dynamic Spectra ◽

Time Structures

The theory of solar radio bursts remains a mystery to most astronomers and astrophysicists. The reasons for this are not hard to identify. First, the solar radioastronomical data are unfamiliar. (The observational data on solar radio bursts is being reviewed separately at this meeting (McLean 1981).) The important features of this data involve frequency-time structures in dynamic spectra, and such features are absent in data on galactic and extra galactic objects. Even for pulsars the data are obtained at discrete frequencies, and the frequency-time structures are not of major importance. Second, the theory itself involves plasma physical concepts which are unfamiliar to most physicists and astronomers. These concepts include those of plasma instabilities, microturbulence, and of particle-wave and wave-wave interactions. Third, one must also admit that there is a prejudice amongst many astronomers against solar physics: the Sun is regarded as interesting only to the extent that it can teach us about other astronomical objects. I shall return to this third point later.

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Can Spontaneously Emitted Langmuir Waves Account for Type III Solar Radio Bursts?

Publications of the Astronomical Society of Australia ◽

10.1017/s1323358000014582 ◽

1976 ◽

Vol 3 (1) ◽

pp. 43-45 ◽

Cited By ~ 1

Author(s):

D. B. Melrose

Keyword(s):

Solar Radio ◽

The Other ◽

Radio Bursts ◽

Solar Radio Bursts ◽

Langmuir Waves ◽

Type Iii ◽

Other Hand ◽

The One ◽

Stream Instability

One of the major problems in the theory of type III solar radio bursts concerns the development of the two-stream instability. On the one hand, Sturrock (1964) argued that one expects the instability to develop rapidly, and if it does it should prevent the stream from propagating through the corona, contrary to observation. On the other hand, one appears to require that the instability develop partially, in the sense that there is some significant amplified emission of Langmuir waves, in order to account for the observed emission.

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Type II Solar Radio Bursts over Solar Cycle 21

International Astronomical Union Colloquium ◽

10.1017/s025292110002546x ◽

1994 ◽

Vol 144 ◽

pp. 283-284

Author(s):

G. Maris ◽

E. Tifrea

Keyword(s):

Solar Radio ◽

Interplanetary Space ◽

Impulsive Phase ◽

Radio Bursts ◽

Type Ii ◽

Solar Radio Bursts ◽

Strong Energy ◽

Mass Ejection ◽

Geophysical Effect ◽

Radio Event

The type II solar radio bursts produced by a shock wave passing through the solar corona are one of the most frequently studied solar activity phenomena. The scientific interest in this type of phenomenon is due to the fact that the presence of this radio event in a solar flare is an almost certain indicator of a future geophysical effect. The origin of the shock waves which produce these bursts is not at all simple; besides the shocks which are generated as a result of a strong energy release during the impulsive phase of a flare, there are also the shocks generated by a coronal mass ejection or the shocks which appear in the interplanetary space due to the supplementary acceleration of the solar particles.

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