Interplanetary Magnetic Field Variations on the Long Time Scales

Abstract

Recurrent sunspot groups are observed during two or more solar rotations and are an important phenomenon in the active regions' evolution study. In this work, we obtained the radial profiles of the vertical component of the magnetic field strength according to the SDO spacecraft data. To obtain the profiles, averaging between the magnetic field strength isolines gradually moving away from the spot's magnetic center to the umbra-penumbra boundary was used. When considering profiles for one sunspot at different moments of its evolution (meaning different crossings of the central meridian), there is a change in the profile of the magnetic field strength. This effect can be explained by the sunspot evolution, which can be used in modeling of the sunspots, including their emerging, development, and dissipation.