Variations of the Position of Perturbation Layer of Solar Frequency Shifts

Abstract

The variation of solar p-mode oscillation frequency with the solar magnetic activity is called the frequency shift, which is considered to be caused by a perturbation in a thin layer near the solar surface. A method for predicting the frequency shift by the magnetic activity index and the solar model had been developed previously. In this method, the frequency shift depends on the intensity of magnetic activity and the position of the perturbing source. The intensity of magnetic activity is considered to be proportional to the magnetic activity index. And the position of the perturbing source was assumed to be fixed previously. This paper has studied the variation of the position of perturbing source. By using the observed p-mode oscillation frequency and Ca II index of the Sun, it is found that the position of perturbing source may be varied with the solar magnetic activity. In the solar maximum year, the position of perturbing source is deeper, but it is shallower in the solar minimum year.