Two-dimensional MHD models of solar magnetogranulation. Testing of the models and methods of Stokes diagnostics

Abstract

We carried out the Stokes diagnostics of new two-dimensional magnetohydrodynamic models with a continuous evolution of magnetogranulation in the course of two hours of the hydrodynamic (solar) time. Our results agree satisfactorily with the results of Stokes diagnostics of the solar small-scale flux tubes observed in quiet network elements and active plages. The straightforward methods often used in the Stokes diagnostics of solar small-scale magnetic elements were tested by means of the magnetohydrodynamic models. We conclude that the most reliable methods are the determination of magnetic field strength from the separation of the peaks in the Stokes V profiles of the infrared Fe I line 1564.8 nm and the determination of the magnetic inclination angle from the ratio tan^2 gamma approx (Q^2 + U^2)^{1/2}/V^2. The lower limits for such determinations are about 20 mT and 10 degree, respectively. We also conclude that the 2D MHD models of solar magnetogranulation are in accord with observations and may be successfully used to study magnetoconvection in the solar photosphere.