Centre-to-limb variation of solar granulation in the infrared

To investigate the physical nature of solar convective zone, we employ the observed frequency shifts of solar oscillations to study the influence of magnetic perturbation inside the Sun on the low-l solar p-mode oscillations. We describe the various possibility of frequency shifts for a time-dependent source of MHD turbulence. For the magnetic perturbation contribution, we obtain the frequency shifts of modes with different degree as a function of the spectrum of fluctuating magnetic field. The frequency shift is found to increase with the strength of magnetic fields in solar interior, and its temporal behavior closely follows the phase of the synthetic solar activity cycle. Our analysis indicates that the magnetic activities cause shifts of up to 0.3 (mu)Hz. It is obviously shown that mode frequency, which is sensitive to the effect of magnetic fields, can be used as a diagnostic tool for the presence of turbulent magnetic fields in the convection zone.