We discuss the physics of the f mode and the helioseismic diagnostics of the subsurface layers, based on the f-mode properties. The distribution of energy of each of the 18 modes considered is shown to be exponential within the statistical error. The independence of the modes is studied by analysing the statistical properties of the sum of their normalized energies. No correlation is detected within the statistical error. Both of these results support the hypothesis of stochastic excitation of the p-modes by turbulent motions in the outer layers of the convection zone.
GOLF is an improved disk-integrated sunlight resonant scattering spectrophotometer.
Unfortunately, due to malfunction on the rotating mechanism, only a series of 26 continuous days are available. Here, a detailed analysis is presented including the value of the averaged magnetic field as well as a power spectrum covering a frequency range up to 12 mHz. This period coincides with the change of solar magnetic structure. Regular behavior is well visible at the beginning of the measurements during five solar rotations, especially for radial modes. Later on it passed through two big pulses and then transformed into the small stochastic perturbations when the solar activity is down.