Study of the Magnetic Properties of Sunspot Umbrae
Abstract
The paper presents the results of the study of sunspots, obtained by the authors and other researchers in recent years. The results regarding the atmosphere above sunspot umbrae, based on the observational data in the spectral lines of the upper chromosphere and lower corona, are discussed. It is shown that individual parameters of the profile of these lines differ in leading and trailing sunspots. A hypothesis about the relationship between the parameters of the profiles of these spectral lines and the parameters of the magnetic field in sunspot umbrae is stated and tested. A comparative analysis of the magnetic properties of the umbrae of leading and trailing sunspots in active regions (ARs) without explosive processes (EPs, id est, formation of coronal mass ejection with solar flare) is carried out. For the analysis, only pairs of magnetically coupled (connected by magnetic field lines) leading and trailing sunspots were selected. It is shown that the values of a number of magnetic field parameters in sunspot umbrae and the character of the relationship between them depend on the type of the sunspots. In particular, in the umbrae of leading and trailing sunspots of close areas, the maximum and average magnitudes of the magnetic induction are different. The dependences of the minimum angle of inclination of the field lines to the radial direction from the center of the Sun and the average inclination angle of the field lines on the umbra areas of leading and trailing sunspots are also different. For magnetically coupled leading and trailing sunspots, it is shown that the distances from the center of the umbra of each type of sunspots to the main polarity separation line of the photospheric field in ARs are different. The paper also discusses the time variation of various magnetic field parameters of the sunspot umbra separately for single and magnetically coupled sunspots, as well as sunspots of magnetically coupled ARs, which we defined as magnetic activity complexes (MACs). The evolution of the magnetic characteristics of sunspots, including sunspots in the MACs, during a radical rearrangement of the magnetic configuration is studied. The influence of EPs on the characteristics of the magnetic field in sunspots is revealed. One of the objectives of this work was to reveal the difference between the properties of sunspots in ARs without EPs and in ARs with various activities, e.g., with solar flares and the formation of coronal mass ejections.
- Publication:
-
Astronomy Reports
- Pub Date:
- February 2022
- DOI:
- 10.1134/S1063772922030064
- Bibcode:
- 2022ARep...66..116Z
- Keywords:
-
- Sun;
- solar activity;
- sunspots;
- explosive processes