Irkutsk, Russian Federation
Irkutsk, Russian Federation
Irkutsk, Russian Federation
The spatial-temporal picture of appearance of active regions and the relationship of their appearance with the structure and development of a large-scale magnetic field were studied during the transition from solar cycle 24 to 25. During this period, solar activity is low, and therefore the dynamics of a large-scale magnetic field in the appearance of new active regions is most noticeable. We have used SDO/HMI data on the longitudinal magnetic field to determine the time and heliographic coordinates of the origin of an active region, as well as daily WSO maps (Wilcox Solar Observatory) to compare with the structure of the large-scale magnetic field. We have obtained the following results. During the transition from one cycle to another, new active regions appeared in half of the cases in the polarity inversion line of the large-scale magnetic field, and almost exclusively at the Hale boundaries in the corresponding hemispheres and solar cycles. In other cases, the places of appearance were unipolar regions of the large-scale magnetic field without a clear advantage in the location of the field regions according to the Hale law. The formation of active regions is preceded or accompanied by changes in the structure of the large-scale magnetic field. At the same time, in the fine structure of the magnetic field in the photosphere we can observe an increase in the magnetic field network on a spatial scale of the size of supergranules and larger, as well as the appearance of small regions of a new magnetic field of both polarities. The appearing active regions were concentrated in two narrow longitudinal zones that covered both hemispheres of the Sun. The new cycle began in the same longitudinal zones, where the activity of the old cycle decayed.
magnetic field, active regions
1. Bai T., Hoeksema J.T., Scherrer P.H. Hot spots and active longitudes: organization of solar activity as a probe of the interior. Proc. the 4th SOHO Workshop on Helioseismology. ESA SP. 1995, vol. 376, p. 113.
2. Bappu M.K.V., Grigorjev V.M., Stepanov V.E. On the development of magnetic fields in the active regions. Solar Phys. 1968, vol. 4, pp. 409-421. DOI:https://doi.org/10.1007/BF00147906.
3. Benevolenskaya E.E., Hoeksema J.T., Kosovichev A.G., Scherrer P.H. The interaction of new and old magnetic fluxes at the beginning of solar cycle 23. Astrophys. J. 1999, vol. 517, pp. L163-L166. DOI:https://doi.org/10.1086/312046.
4. Bumba V., Howard R. A study of the development of active regions on the Sun. Astrophys. J. 1965, vol. 141, pp. 1492-1501. DOI:https://doi.org/10.1086/148237.
5. Duvall T.L.Jr., Wilcox J.M., Svalgaard L., Scherrer P.H., McIntosh P.S. Comparison of Hα synoptic charts with the large-scale solar magnetic field as observed at Stanford. Solar Phys. 1977, vol. 55, pp. 63-68. DOI:https://doi.org/10.1007/BF00150874.
6. Grigor’ev V.M., Ermakova L.V. Magnetic field variations before the birth of an active region. Bull. Solnechnye Dannye. 1976, no. 4, pp. 83-92. (In Russian).
7. Grigoryev V.M., Peshcherov V.S. On the development of a background magnetic field in the formation of a new active region. Astr. Tsirkulyar. 1986, no. 1427, pr. 4-6. (In Russian).
8. Grigor’ev V.M., Ermakova L.V., Khlystova A.I. Dynamics of magnetic tubes during the formation of a large sunspot. Astronomy Reports. 2012, vol. 56, no. 11, pp. 878-886. DOI:https://doi.org/10.1134/S1063772912110030.
9. Hathaway D.H., Upton L., Colegrove O. Giant convection cells found on the Sun. Science. 2013, vol. 342, pp. 1217-1219. DOI: 10.11.26/science.1244682.
10. Hotta H., Rempel M., Yokohama T. High-resolution calculation of the solar global convection with the reduced speed of sound technique. II. Near surface shear layer with the rotation. Astrophys. J. 2015, vol. 798, rr. 51-66. DOI:https://doi.org/10.1088/0004-637X/798/1/51.
11. Matsumoto R., Tajima T., Chou W., Okubo A., Shibata K. Formation of kinked alignment of solar active regions. Astrophys. J. 1998, vol. 493, pp. L43-L46. DOI:https://doi.org/10.1086/311116.
12. McIntosh P.S. The birth and evolution of sunspots. Observations. Proc. the Conference “The Physics of Sunspots”. Sunspot, NM, July 14-17, 1981. (A83-18101 06-92). 1981, pp. 7-54.
13. McIntosh P.S. Wilson P.R. A new model for flux emergence and the evolution of sunspots and the large-scale fields. Solar Phys. 1985, vol. 97, pp. 59-79. DOI:https://doi.org/10.1007/BF00152979.
14. Miesch M.S., Brun A.S., DeRosa M.L., Toomre J. Structure and evolution of giant cells in global models of solar convection. Astrophys. J. 2008, vol. 673, pp. 557-575. DOI:https://doi.org/10.1086/523838.
15. Ograpishvili N.B. Large-scale structure of background fields and active region. Solar Phys. 1988, vol. 115, pp. 33-41. DOI:https://doi.org/10.1007/BF00146228.
16. Ruzmaikin A.A. Clustering of emerging magnetic flux. Solar Phys. 1998, vol. 181, pp. 1-12. DOI:https://doi.org/10.1023/A:1016563632058.
17. Scherrer P.H., Schou J., Bush R.I., Kosovichev A.G., Bogart R.S., Hoeksema J.T., Liu Y., Duvall Jr. T.L., Zhao J., Title A.M., Schrijver C.J., Tarbell T.D., Tomczyk S. The Helioseismic and Magnetic Imager (HMI) investigation for the Solar Dynamics Observatory (SDO). Solar Phys. 2012, vol. 275, pp. 207-227. DOI:https://doi.org/10.1007/s11207-011-9834-2.
18. Stepanyan N.N. Background magnetic fields and solar activity. Izvestiya Krymskoi Astrofizicheskoi Observatorii. 1985, vol. 71, pp. 62-68. (In Russian).
19. Vitinsky Yu.I., Kopetsky M., Kuklin G.V. Statistics of the spot-forming activity of the sun. Moscow, Nauka Publ., 1986, 296 p. (In Russian).
20. URL: http://wso.stanford.edu (accessed May 15, 2022
