Type III solar radio bursts

• We extended the metric type III theory to decimetric frequencies and to both downgoing and upgoing type III bursts, showing that fundamental-harmonic structure should be common only in the metric frequency range, as observed [Robinson and Benz, 2000]. The predicted dynamic spectra appear consistent with available data.
• We reviewed our earlier SGT theory of metric type III solar radio bursts [Cairns et al., 2000b; Robinson and Cairns, 2001]. This detailed theory for type III bursts predicts dynamic spectra with the observed timescales, frequency ranges, and spectral densities. It can also explain the fundamental-harmonic structure and the exponential decay of the radiation at a given frequency. No quantitative or even semi-quantitative competitor exists for the theory, which appears consistent with the available observational data and can, moreover, be used to constrain the properties of density irregularities and the electron beam as a function of heliocentric distance.

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