Effects of magnetic fibrils on solar oscillation frequencies - Mean field theory

Abstract

It is quite likely that the solar interior magnetic field retains the fibril structure observed at photospheric levels down to some significant depth in the convection zone. Furthermore, previous work has shown that the effect of magnetic fibrils on p-mode oscillation frequencies is enhanced by 1/f, the reciprocal of the fibril filling factor, over the effect of an equal amount of flux in diffuse form. Previous calculations have used multiple scattering methods which effectively preclude the inclusion of stratification or consideration of realistic geometries. In this paper an alternative simpler method of treating fibrils is developed on the basis of mean-field theory originally developed by Parker (1982).