Evidence of Plasma Resonance Instability from Observations of Solar Decimetric Fine Structures

Abstract

The solar radio emissions in the decimetric frequency range (above 1000 MHz) are very rich in temporal and/or spectral fine structures. The Brazilian Solar Spectroscope (BSS) at INPE started operating in 1998. Since then, various types of fine structures, in the frequency range of (1000-2500) MHz, with high time and frequency resolutions have been recorded. The observed bursts include dot-like emissions and chains of dots, lace bursts exhibiting intensity variations as a function of frequency and zebra pattern emissions. It is suggested that they can be generated by a plasma resonance intestability mechanism. This model can explain many features of the observed fine structures.