Solar Faculae: Microturbulence as an Indicator of Inclined Magnetic Fields

Abstract

The observations of the solar facula in the Ba II λ 455.403 A line are used to construct a 3D model of the facula area by solving the inverse nonequilibrium radiative transfer problem and to investigate the fine structure of the field of unresolved velocities (microturbulence). New turbulent structures are formed in the layers of the upper photosphere. They are localized mainly between upward and downward flows with the formation of ring-shaped structures of increased turbulence around these flows. The mechanism of magnetic anisotropy of microturbulent velocity is proposed (small-scale eddy-type plasma motions mainly occur in the planes perpendicular to the magnetic field), which explains the height dependence of the field of unresolved velocities. Anisotropy of microturbulence begins to manifest itself in the lower photospheric layers outside the upward and downward flows, while it manifests itself in the higher layers inside these flows. The increase of microturbulence in the layers of the upper photosphere and the lower chromosphere in the areas between matter flows indicates the presence of inclined magnetic fields, which, along with the blurring of its spatial structure, indicates the existence of a magnetic canopy region. Microturbulence can be used as an additional tool for diagnostics of inclined magnetic fields.