An inhomogeneous model of the chromosphere and lower corona for the interpretation of data on the radio emission of the quiet sun in the millimeter wavelength range

A method is proposed for calculating the spectrum and distribution of radio brightness over the disk of the quiet sun for an inhomogeneous model of the chromosphere and lower corona, including spicules. A number of inhomogeneous models of the solar atmosphere are considered which allow one to explain the observed variation in the spectral index of solar radio emission in the millimeter range at wavelengths of 5--9 mm. A spectral dependence closest to the observed one is obtained for two models, one of which has an inversion of the electron concentration in the interspicule medium at heights of 2000--2500 km above the photosphere. Distributions of radio brightness over the solar disk at wavelengths of 1, 2, 3, 4, 6, and 8 mm are obtained for this model. The results of the calculations are in qualitative agreement with a number of observational data at wavelengths of 1--4 mm. The comparison with experiment permits the conclusion that the temperature in the spicules must be 5000/sup 0/K or even lower at their bases and about 6000/sup 0/K at the heights where the emission at wavelengths of more than 4 mm is generated.