The paper provides statistical data on solar activity complexes (ACs) observed in solar cycle 21. From the synoptic charts for the 1976–1986 sunspot activity, we have detected the regions where the sunspot generation was observed at least through three Carrington Rotations (CRs). These regions were identified as AC cores. We have compiled an AC catalogue. ACs are shown to evolve quasi-periodically, in pulses that are 15–20 rotations long. We have analyzed the North-South asymmetry in the AC location. In cycle 21, 90 % of the proton flares that affected the natural environment are shown to have occurred in ACs. We note a tendency for AC activity to decrease, as well as the manifestation of the Gnevyshev—Ohl rule in AC properties, in solar cycles 21–24.
solar activity, activity complexes, flares, North-South asymmetry
1. Banin V.G. The May 1981 complex of activity and large flares. Issledovaniya po ge-omanetizmu, aeronomii i fizike Solntsa [Research on Geomagnetism, Aeronomy and Solar Physics]. 1983, iss. 65, pp. 129–150. (In Russian).
2. Banin V.G., Yazev S.A. Areas of long-lived activity on the descending branch of solar cycle 21. Kinematika i fizika nebesnykh tel [Kinematics and Physics of Celestial Bod-ies]. 1989, vol. 5, no. 4, pp. 62–68. (In Russian).
3. Banin V.G., Yazev S.A. ALAs in solar activity cycles. Konrerentsiya, posvyashchen-naya pamyati M.N. Gnevysheva i A.I. Olya “Sovremennye problem solnechnoi tsi-klichnosti” Proc. [The Conference in Memory of M.N. Gnevyshev and A.I. Ohl “Cur-rent Problems of Solar Cyclicity”]. Saint Petersburg. 1997, pp. 9–13. (In Russian).
4. Banin V.G., Borovik A.V., Trifonov V.D., Yazev S.A. On the Baikal Astrophysical Observatory astroclimate. Issledovaniya po geomanetizmu, aeronomii i fizike Solntsa [Research on Geomagnetism, Aeronomy and Solar Physics]. 1982, iss. 60, pp. 28–34. (In Russian).
5. Banin V.G., Borovik A.V., Yazev S.A. Complexes of activity in 1705–1709 Carring-ton rotations. Solnechnye dannye [Solar Data]. 1988, no. 5, pp. 82–88. (In Russian).
6. Borovik A.V., Golovko A.A., Polyakov V.I., Trifonov V.D., Yazev S.A. SOLAR ac-tivity research at the Baikal Astrophysical Observatory of ISTP SB RAS. Solar-Terrestrial Physics. 2019, vol. 5, iss. 3, pp. 18–28. DOI: 10.12737/stp-53201903.
7. Bray R.J, Loughhead R.E. Solnechnye pyatna [Sunspots]. Moscow, Mir, 1967. 383 p. (In Russian).
8. Bumba V., Howard R. Large-scale distribution of solar magnetic fields. Astrophys. J. 1965, vol. 141, no. 4, pp. 1502–1512. DOI: 10.1086/148238.
9. Bumba V., Kalman B., Klvana M., Suda J. Kinematics of the May 1981 flare com-plex’s magnetic field decrease (H.R. 17 644). Bull. Astron. Inst. Czechosl. 1986, vol. 37, pp. 219–226.
10. Castenmiller M.J.M., Zwaan C., Van der Zalm. Sunspot nests. Manifestation of se-quences in magnetic activity. Solar Phys. 1986, vol. 105, pp. 237–255.
11. Golovko A.A. Some peculiarities in structures of the activity complex that pro-duced power proton flares on May 13–16, 1981. Issledovaniya po geomanetizmu, aer-onomii i fizike Solntsa [Research on Geomagnetism, Aeronomy and Solar Physics]. 1983, iss. 65, pp. 121–129. (In Russian).
12. Golovko A.A. Structure and distribution of magnetic field and radio emission in the active region 7978 that produced power flares in July 1996. Trudy GAISh [Astronomi-cal and Astrophysical Transactions]. Moscow, 2001, vol. 71, pp. 177–183. (In Rus-sian).
13. Gaizauskas V., Harvey K.L., Harvey J.W., Zwaan C. Large-scale patterns formed by active solar regions during the ascending phase of cycle 21. Astrophys. J. 1983, vol. 265, pp. 1056–1065. DOI: 10.1086/160747.
14. Howard R., Svestka Z. Development of a complex of activity in the solar corona. So-lar Phys. 1977, vol. 54, pp. 65–105. DOI: 10.1007/BF00146426.
15. Ilonidis S., Zhao J., Kosovichev A. Detection of emerging sunspot regions in solar in-terior. Science. 2011, vol. 333, pp. 993–996. DOI: 10.1126/science.1206253.
16. Isaeva E.S., Tomozov V.T., Yazev S.A. Proton flares in solar activity complexes: pos-sible origins and consequences. Astron. Rep. 2018. Vol. 62, no. 3. PP. 243–250. DOI: 10.1134/ S1063772918030058.
17. Isaeva E.S., Tomozov V.M., Yasev S.A. X-Ray flares and activity complexes on the Sun in solar cycle 24. Astron. Rep. 2020, vol. 64, no. 1, pp. 58–65. DOI: 10.1134/S1063772920010035.
18. Ishkov V.N. Space weather and specific features of the development of current solar cycle. Geomagnetism and Aeronomy. 2018, vol. 58, no. 6, pp. 785-800. DOI: 10.1134/ S0016794018060056.
19. Ishkov V.N., Kotrc PP., Kulcar L. Complexes of active regions evolution, connections with solar flares and distributions in the 20 and 21 cycles of solar activity. Proc. the International Workshop “Solar Maximum Analysis”. Additional Iss. Irkutsk, USSR, 17–24 June 1985. Novosibirsk: Nauka, Siberian Division, 1988, pp. 119–123.
20. Kitchatinov L.L., Khlystova A.I. North-south asymmetry of solar dynamo in the current activity cycle. Astron. Lett. 2014, vol. 40, pp. 663–666. DOI: 10.1134/S1063773714100028.
21. Komarova E.S., Sidorov V.I., Yazev S.A. Peculiarities of solar flare development on 19 of October 2001. Solnechno-zemnaya fizika [Solar-Terrestrial Physics]. 2004, iss. 6, pp. 90–92. (In Russian).
22. Kosovichev A.G., Duvall JR T.L. Active region dynamics. Recent helioseismology re-sults dynamics. Solar dynamics and its effects on the heliosphere and Earth. Dordrecht, The Netherlands-Springer, 2006, pp. 1–12.
23. Mogilevsky E.I., Shilova N.S. Complexes of active regions on the Sun. I. Izvestiya Krymskoi Astrofizicheskoi Observatorii [Bull. of the Crimean Astrophysical Observa-tory]. 1998, vol. 94, pp. 60–71. (In Russian).
24. Obridko V.N. Solnechnye pyatna i kompleksy aktivnosti [Sunspots and complexes of activity]. Moscow, Nauka, 1985, 256 p. (In Russian).
25. Obridko V.N., Shelting B.D. Global complexes of activity. Astronomy Reports. 2013, vol. 57, iss. 10, pp. 786-796. DOI: 10.1134/S1063772913100041.
26. Obridko V.N., Nagovitsyn Yu.A. Solnechnaya aktivnost’, tsiklichnost’ i metody prognoza [Solar activity, Cyclicity and Forecast Techniques]. Saint Petersburg, VVM Publ., 2017, 466 p. (In Russian).
27. Ogir’ M.B. Development of sunspot groups in complexes of activity. Fizika solnechnykh pyaten [Physics of Sunspots] Moscow, Nauka, 1976, pp. 168–171. (In Russian).
28. Olemskoy S.V., Kitchatinov L.L. Grand minima and north-south asymmetry of solar activity. Astrophys. J. 2013. Vol. 777, iss. 1, article id. 71, pp. 71. DOI: 10.1088/0004-637X/777/1/71.
29. Penn M.J., Livingston W. Long-term evolution of sunspot magnetic fields. Proc. IAU Symposium “The Physics of Sun and Star Spots”. 2010, no. 273, pp. 126–133.
30. Ryabov M.I., Lukashuk S.A. Complexes of activity and their response to anomalous activity of northern and southern hemispheres on the Sun. Tsikly aktivnosti na Solntse i zvezdakh [Activity cycles on the Sun and stars]. Saint Petersburg, VVM Publ., 2009, pp. 121–134.
31. Sattarov I.S. On the development of complexes of activity on the Sun. Solnechnye dannye [Solar Data]. 1989, no. 5, pp. 93–100. (In Russian).
32. Sattarov I.S., Saidalieva M.A. The last complex of activity of the cycle 21. Issle-dovaniya solnechnoi aktivnosti [Research into Solar Activity]. Eds. Yuldashbaeva T.S. and Korobova Z.B. Tashkent, FAN AN Uzbek SSR Publ., 1991, pp. 16–25. (In Russian).
33. Sattarov I.S., Sherdanov Ch.T., Ladenkov O.V. X-ray structure of complexes of activity on the Sun. Trudy GAISh [Astronomical and Astrophysical Transactions]. Moscow, 2001, vol. 71, pp. 219–222. (In Russian).
34. Vitinsky Yu.I. On some peculiarities of solar activity centers. Izvestiya Glavnoi as-tronomicheskoi observatorii v Pulkovo [Bull. of the Central Astronomical Observatory at Pulkovo]. Leningrad, CAO Publ., 1965, vol. 24, iss. 2, no. 178, pp. 49–59. (In Rus-sian).
35. Vitinsky Yu.I., Kopecky M., Kuklin G.V. Statistika pyatnoobrazovatelnoi deyatelnosti Solntsa [Statistics of sunspot-forming activity of the Sun]. Moscow, Nau-ka, 1986, 296 p. (In Russian).
36. Wang Y.M., Sheeley N.R. Average properties of bipolar magnetic regions during sun-spot cycle 21. Solar Phys. 1989, vol. 124, pp. 81–100. DOI: 10.1007/BF00146521.
37. Yazev S.A. Complexes of activity on the Sun in 1980–2008. Comments to the cata-logue of data. Izvestiya Irkutskogo gosudarstvennogo universiteta. Seriya Nauki o Zemle [Bull. of the Irkutsk State University. Ser. Earth Sciences] 2010a, vol. 3, no. 2, pp. 217–225. (In Russian).
38. Yazev S.A. Complexes of activity on the Sun during solar cycle 23. Solnechno-zemnaya fizika [Solar-Terrestrial Physics]. 2010b, iss. 16, pp. 94–101. (In Russian).
39. Yazev S.A. Complexes of activity on the Sun in 24 cycle of solar activity. Astronomy Reports. 2015, vol. 92, no. 3, pp. 260–269. DOI: 10.7868/S000462991503007X. (In Russian).
40. Yazev S.A., Korotkikh A.V., Tarlyuk I.G. Complexes of activity on the Sun in Schwabe—Wolf cycles. Solnechno-zemnaya fizika [Solar-Terrestrial Physics]. 2011, iss. 19, pp. 3–8. (In Russian).
41. URL: https://umbra.nascom.nasa.gov/SEP (accessed July 5, 2021).