On the Envelope Soliton – Like Fine Structure in Solar Radio Emission
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文摘
Several quasi-periodic, milliseconds fine structures in the metric wave bandoccurring during the evolution of solar type IV bursts have been observed byYunnan Radio Telescope, Trieste Radio Telescope and IZMIRAN dynamicspectrometer. The envelope of these quasi-period modulational fine structureshave a soliton pattern, so it is called an envelope soliton-like finestructure. A modulational instability model of electromagnetic wave has beenadopted here. It is found that the longitudinal modulational instability canoccur only in the solar coronal region of low magnetic field and hightemperature, as well as high density plasma, which will give rise to theenvelope soliton-like fine structures in the solar metric and decimetricradio emission. The propagation effects of envelope soliton-like finestructure from corona to the observer on the Earth have been brieflyconsidered.