Stability and equilibrium of emerged magnetic flux

摘要: We analyse stability and equilibrium of a unipolar large-scale magnetic field pervading plane horizontal subphotospheric layer with the possible implications for sunspots in mind. Eddy diffusivity is applied to account effects small-scale convective turbulence. Diffusivity quenching by results secondary instability. A linear analysis performed define marginal boundary parametric space unstable mode structure. The nonlinear dynamics modes are followed numerically. original state uniform vertical transformed via instability into dynamical highly intermittant distribution field. Magnetic flux concentrated relatively small area surrounded an almost field-free region. role fluid motion hydromagnetic emphasized. Although relevance process sunspot formation rather questionable, resulting structures similar mature spots their thermal properties. Also, simulated flow structure agrees helioseismic tomography results.