Cyclic variations in the areas of coronal holes and sunspots in 2010–2021
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Abstract
The paper investigates a cyclic relation between coronal holes (CHs) and solar activity (SA) indices. Based on observational data obtained with the SDO/AIA instrument in the Fe XII 19.3 nm line between May 13, 2010 and May 13, 2021, the properties of polar and nonpolar coronal holes are studied. The features of each group are considered in detail, and the relationship of CH areas with the phase of the solar cycle is established. During the period under study, a north-south (N-S) asymmetry of the hemispheres was detected both in the SA indices and in the localization of the maximum areas of polar and nonpolar CHs. The determining role of polar CHs of the southern hemisphere and nonpolar CHs of the northern hemisphere was revealed throughout the cycle, which manifested itself in the SA dynamics of the hemispheres and the solar disk as a whole.
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References
Andreeva A.O., Malashchuk V.M., 2020. Geomagnetism and Aeronomy, vol. 60, no. 8, pp. 1093–1100.
Andreeva O.A., Abramenko V.I. and Malaschuk V.M., 2020. Astrophysics, vol. 63, no. 1, pp. 114–124, doi:10.1007/s10511-020-09619-2.
Akhtemov Z.S., Tsap Y.T., Haneychuk V.I., 2020. Astrophysics, vol. 63, pp. 399–407.
Barra V., Delouille V., Kretzschmar M., Hochedez J.-F., 2009. Astron. Astrophys., vol. 505, pp. 361–371.
Bilenko I.A., Tavastsherna K.S., 2016. Solar Phys., vol. 291, pp. 2329–2352.
Bohlin J.D., Sheeley N.R., Jr., 1978. Solar Phys., vol. 56, pp. 125–151.
Bravo S., Otaola J.A., 1989. Solar Phys., vol. 122, pp. 335–443.
Bravo S., Stewart G.A., 1994. Solar Phys., vol. 154, pp. 377–384.
Bravo S., Stewart G.A., 1997. Solar Phys., vol. 173, no. 1, pp. 193–198.
Hess Webber S.A., Karna N., Pesnell W.D., Kirk M.S., 2014. Solar Phys., vol. 289, no. 11, pp. 4047–4067.
Hoyng P., 1993. Astron. Astrophys., vol. 272, pp. 321–339.
Hurlburt N., Cheung M., Schrijver C., et al., 2012. Solar Phys., vol. 275, pp. 67–78.
Ikhsanov R., Ivanov V., 1999. Solar Phys., vol. 188, pp. 245–258.
Sheeley N.R., Jr. & Harvey J.W., 1981. Solar Phys., vol. 70, pp. 237–249.
Verbeeck C., Delouille V., Mampaey B., De Visscher R., 2014. Astron. Astrophys., vol. 561, id A29.