A model for the outer solar atmosphere devoid of activity

A model for the transition region between the solar chromosphere and corona is constructed using brightness temperatures for the center of the quiet Sun derived from observations on the RATAN-600 radio telescope. The model was refined using differential emission measures determined from all available short-wavelength line data. The transition region model is supplemented with data on the quiescent chromosphere and corona. This model, constructed using radio data over the solar disk, is suggested as a model for the outer solar atmosphere in the absence of any apparent activity. The problem of heat transfer from the corona downward is examined in order to elucidate the nature of the transition region. A solution of the stationary problem for various relations between the heat flux and total emission in lines at short wavelengths is obtained. The empirical model constructed is shown to correspond to an atmosphere with a narrow transition region formed by the heat flux from the corona downward, with radiation losses primarily determining the atmospheric structure.