Effect of Explosive Processes on the Sun on the Inclination Angles of Magnetic Field Lines in Sunspot Umbrae

In this paper, we study the effect of explosive processes (EPs) on the Sun on the magnetic properties of sunspot umbrae in active regions (ARs). Explosive processes include the formation of coronal mass ejections (CMEs) and/or flares. As a characteristic of the field in sunspot umbrae, we chose here the inclination angles of the field lines to the radial direction from the center of the Sun α min (the minimal angle within sunspot umbra) and 〈α〉 (the average angle within sunspot umbra). It is shown that EPs in such ARs can significantly affect both the nature of the change with time in α min and 〈α〉 in sunspot umbra and the nature of their oscillations. Most significantly, the behavior of the angles α min and 〈α〉 in the sunspot shadow after the onset of flare changes during the event are associated with the emergence of the fastest considered CME and with a powerful solar flare. Our preliminary analysis showed that the strongest and sharpest changes in α min and 〈α〉 occur in sunspot umbra with the smallest sizes and/or in sunspots that are closest to the site of EP occurrence. Presumably, the reason for the change in the behavior of the inclination angles of the field lines after the flare onset is the effect of the horizontal Lorentz force on the magnetic tubes emerging from the spot shadows. The electric currents participating in the formation of such a force arise during the transformation of the magnetic field in the solar atmosphere during the formation of a CME and/or the occurrence of a flash. A preliminary analysis included the oscillation features of α min and 〈α〉 in the AR with observed various EPs and, separately, for comparison, in an AR with a sunspot group in the absence of such processes. The α min and 〈α〉 values were found with vector measurements of the photospheric field with the SDO/HMI instrument.