Modified 3D Model of a Facular KNOT

The paper presents a modified version of a previously published 3D model of the solar facular knot (Solov'ev and Kirichek, 2019), which successfully describes the main structural features of the solar facular formations. As in the main model, we use the solution (Schatzman, 1965) in the potential approximation as the basis of the magnetic structure of the facular element. The magnetic profile of the facula, as before, has the shape of a fountain, in which thin streams of plasma rise in the center of the node and flow on its periphery along magnetic field lines. This configuration is very similar to the observed patterns (Lites et al., 2004; Jafarzadeh et al., 2017; Pietarila et al., 2009). In the new modified facula model, we use a different method to introduce force corrections into the potential distribution of the magnetic field, which causes the appearance of additional terms in the formulas for pressure and density. In the new version of the model, a change in only geometric parameters leads to a sharp change in the temperature profiles of the facular knot: instead of a dark central dip in the center of the assembly, a bright, hot formation can occur. An observational example of such a large-scale transformation is found in the Solar Dynamics Observatory data.