Gopasyuk O. Magnetic field structure in active regions and plasma motions in sunspot umbrae on the Sun

The method of investigations of magnetic field in active regions on the bases measured longitudinal fields in the chromosphere and the photosphere simultaneously was elaborated. It was established that the magnetic field in the chromosphere is the force - free magnetic field. This magnetic field is a superposition of the potential field and the field generated by currents in the chromosphere. The vertical and azimuthal electric currents in the chromospheric magnetic features above sunspots and the vertical electric currents in the photosphere above simple sunspot umbrae were calculated. Vertical gradients of the magnetic fields are determined on the bases of three components of magnetic fields in the active regions. It is found that vertical gradients of the magnetic fields in the sunspot are decreasing with increasing of the observed field twisting in the photosphere. The method of the reconstruction of all three components of both the magnetic and velocity field vectors from them sight-of-line compon ents was elaborated. The properties of the plasma motions in the photosphere, chromosphere and temperature minimum region above the simple sunspot umbrae in the magnetic fields were established.