Dynamics of near-polar magnetic field of the Sun at the maximum of solar cycle 24
|1Pishkalo, MI, 1Leiko, UM |
1Astronomical Observatory of Taras Shevchenko National University of Kyiv, Kyiv, Ukraine
|Kinemat. fiz. nebesnyh tel (Online) 2016, 32(2):37-47|
|Start Page: Solar Physics|
Data on the magnitude and the sign of the near-polar magnetic field of the Sun near maximum of solar cycle 24 were analyzed. Polar field observations from the Wilcox Solar Observatory and synoptic magnetic maps from the project SOLIS and the Helioseismic and Magnetic Imager (HMI) were used. We investigated dynamics of total magnetic field at near-polar zones of different size on latitude in north and south hemispheres. We found the epochs of the polar magnetic field reversals. There were triple polar magnetic field reversal in the northern hemisphere and single reversal in the southern hemisphere. The magnetic field reversal in northern he¬mi¬sphere was finished an year earlier than in the southern one. The results were also compared with data on polar magnetic field reversals in previous solar cycles.
|Keywords: magnetic field, solar cycle, the Sun|
1.M. I. Pishkalo, V. P. Babii, and V. G. Ivanchuk, “North-south asymmetry of solar activity and Sun’s global magnetic field reversals during 21, 22 and 23 cycles of activity,” Visn. Kyiv. Univ. Astronomy. 41–42, 98–103 (2005).
2.H. D. Babcock, “The Sun’s polar magnetic field,” Astrophys. J. 130, 364–366 (1959).
3.H. W. Babcock, “The topology of the Sun’s magnetic field and the 22-year cycle,” Astrophys. J. 133, 572–587 (1961).
4.C. J. Durrant and P. R. Wilson, “Observations and simulations of the polar field reversals in cycle 23,” Sol. Phys. 214, 23–39 (2003).
5.N. Karna, S. A. Hess Webber, and W. D. Pesnell, “Using polar coronal hole area measurements to determine the solar polar magnetic field reversal in solar cycle 24,” Sol. Phys. 289, 3381–3390 (2014).
6.R. B. Leighton, “A magneto-kinematic model of the solar cycle,” Astrophys. J. 156, 1–26 (1969).
7.V. I. Makarov and K. R. Sivaraman, “On epochs of polarity reversals of the polar magnetic field of the Sun during 1870–1982,” Bull. Astron. Soc. India 14, 163–167 (1986).
8.V. I. Makarov and K. R. Sivaraman, “Evolution of latitude zonal structure of the large-scale magnetic field in solar cycles,” Sol. Phys. 119, 35–44 (1989).
9.A. V. Mordvinov and S. A. Yazev, “Reversals of the Sun’s polar magnetic fields in relation to activity complexes and coronal holes,” Sol. Phys. 289, 1971–1981 (2014).
10.M. Ossendrijver, “The solar dynamo,” Astron. Astrophys. Rev. 11, 287–367 (2003).
11.G. J. D. Petrie, “Evolution of active and polar photospheric magnetic fields during the rise of cycle 24 compared to previous cycles,” Sol. Phys. 281, 577–598 (2012).
12.G. J. D. Petrie, K. Petrovay, and K. Schatten, “Solar polar fields and the 22-year activity cycle: observations and models,” Space Sci. Rev. 186 (1–4), 325–357 (2014).
13.D. Shiota, S. Tsuneta, M. Shimojo, et al., “Polar field reversal observations with Hinode,” Astrophys. J. 753, 157 (2012).
14.H. B. Snodgrass, J. M. Kress, and P. R. Wilson, “Observations of the polar magnetic fields during the polarity reversals of cycle 22,” Sol. Phys. 191, 1–19 (2000).
15.X. Sun, J. T. Hoeksema, Y. Liu, and J. Zhao, “On polar magnetic field reversal and surface flux transport during solar cycle 24,” Astrophys. J. 798, 114 (2015).
16.L. Svalgaard, T. L. Duvall, and P. H. Scherrer, “The strength of the Sun’s polar fields,” Sol. Phys. 58, 225–239 (1978).
17.L. Svalgaard and Y. Kamide, “Asymmetric solar polar field reversals,” Astrophys. J. 763, 23 (2013).
18.L. Upton and D. H. Hathaway, “Predicting the Sun’s polar magnetic fields with a surface flux transport model,” Astrophys. J. 780, 5 (2014).
19.Y.-M. Wang, A. G. Nash, and N. R. Sheeley, “Magnetic flux transport on the sun,” Science 245, 712–718 (1989).
20.D. F. Webb, J. M. Davis, P. S. McIntosh, “Observations of the reappearance of polar coronal holes and the reversal of the polar magnetic field,” Sol. Phys. 92, 109–132 (1984).