Solar Physics

, 292:174 | Cite as

Structure of the Photospheric Magnetic Field During Sector Crossings of the Heliospheric Magnetic Field

  • Tibebu Getachew
  • Ilpo Virtanen
  • Kalevi Mursula


The photospheric magnetic field is the source of the coronal and heliospheric magnetic fields (HMF), but their mutual correspondence is non-trivial and depends on the phase of the solar cycle. The photospheric field during the HMF sector crossings observed at 1 AU has been found to contain enhanced field intensities and definite polarity ordering, forming regions called Hale boundaries. Here we separately study the structure of the photospheric field during the HMF sector crossings during Solar Cycles 21 – 24 for the four phases of each solar cycle. We use a refined version of Svalgaard’s list of major HMF sector crossings, mapped to the Sun using the solar wind speed observed at Earth, and the daily level-3 magnetograms of the photospheric field measured at the Wilcox Solar Observatory in 1976 – 2016. We find that the structure of the photospheric field corresponding to the HMF sector crossings and the existence and properties of the corresponding Hale bipolar regions varies significantly with solar cycle, solar cycle phase, and hemisphere. The Hale boundaries in more than half of the ascending, maximum, and declining phases are clear and statistically significant. The clearest Hale boundaries are found during the (+,−) HMF crossings in the northern hemisphere of odd Cycles 21 and 23, but less systematical during the (+,−) crossings in the southern hemisphere of even Cycles 22 and 24. No similar difference between odd and even cycles is found for the (−,+) crossings. This shows that the northern hemisphere has a more organized Hale pattern overall. The photospheric field distribution also depicts a larger area for the field of the northern hemisphere during the declining and minimum phases, in a good agreement with the bashful ballerina phenomenon.


Sun: photosphere Sun: magnetic fields Sun: activity Sun: heliosphere Sun: solar wind 



We acknowledge the financial support by the Academy of Finland to the ReSoLVE Centre of Excellence (project no. 272157). The Wilcox Solar Observatory data used in this study were obtained via the web site courtesy of J.T. Hoeksema. The OMNI data were obtained from the GSFC/SPDF OMNIWeb interface at . We thank L. Svalgaard for the HMF polarity data. We are also grateful to the National Geophysical Data Center and the WDC-SILSO, Royal Observatory of Belgium, Brussels, for the sunspot data.

Disclosure of Potential Conflicts of Interest

The authors declare that they have no conflicts of interest.


  1. Akasofu, S.-I.: 2014, Single spots, unipolar magnetic regions, and pairs of spots. Geophys. Res. Lett. 41, 3698.  DOI. ADS. ADSCrossRefGoogle Scholar
  2. Akasofu, S.-I.: 2015, Single spots, unipolar magnetic regions, and pairs of spots: 2. The development of sunspot pairs and the Hale boundary. Geophys. Res. Lett. 42, 2571.  DOI. ADS. ADSCrossRefGoogle Scholar
  3. Antonucci, E., Svalgaard, L.: 1974, Green corona and solar sector structure. Solar Phys. 36, 115.  DOI. ADS. ADSCrossRefGoogle Scholar
  4. Babcock, H.D.: 1959, The Sun’s polar magnetic field. Astrophys. J. 130, 364.  DOI. ADS. ADSCrossRefGoogle Scholar
  5. Balogh, A., Erdős, G.: 2013, The heliospheric magnetic field. Space Sci. Rev. 176, 177.  DOI. ADS. ADSCrossRefGoogle Scholar
  6. Benevolenskaya, E.E.: 2007, Polar magnetic field reversals on the Sun. Highlights Astron. 14, 273.  DOI. ADS. ADSzbMATHGoogle Scholar
  7. Cliver, E.W., Richardson, I.G., Ling, A.G.: 2013, Solar drivers of 11-yr and long-term cosmic ray modulation. Space Sci. Rev. 176, 3.  DOI. ADS. ADSCrossRefGoogle Scholar
  8. Crooker, N.U., Lazarus, A.J., Phillips, J.L., Steinberg, J.T., Szabo, A., Lepping, R.P., Smith, E.J.: 1997, Coronal streamer belt asymmetries and seasonal solar wind variations deduced from Wind and Ulysses data. J. Geophys. Res. 102, 4673.  DOI. ADS. ADSCrossRefGoogle Scholar
  9. Dittmer, P.H.: 1975, The relationship between solar flares and solar sector boundaries. Solar Phys. 41, 227.  DOI. ADS. ADSCrossRefGoogle Scholar
  10. Durrant, C.J., Wilson, P.R.: 2003, Observations and simulations of the polar field reversals in cycle 23. Solar Phys. 214, 23.  DOI. ADS. ADSCrossRefGoogle Scholar
  11. Erdős, G., Balogh, A.: 2010, North–South asymmetry of the location of the heliospheric current sheet revisited. J. Geophys. Res. 115, A01105.  DOI. ADS. ADSGoogle Scholar
  12. Hiltula, T., Mursula, K.: 2006, Long dance of the bashful ballerina. Geophys. Res. Lett. 33, L03105.  DOI. ADS. ADSCrossRefGoogle Scholar
  13. Hoeksema, J.T.: 2010, Evolution of the large-scale magnetic field over three solar cycles. In: Kosovichev, A.G., Andrei, A.H., Rozelot, J.-P. (eds.) IAU Symposium 264, 222.  DOI. ADS. Google Scholar
  14. Hoeksema, J.T., Wilcox, J.M., Scherrer, P.H.: 1983, The structure of the heliospheric current sheet – 1978 – 1982. J. Geophys. Res. 88, 9910.  DOI. ADS. ADSCrossRefGoogle Scholar
  15. Hudson, H.S., Svalgaard, L., Hannah, I.G.: 2014, Solar sector structure. Space Sci. Rev. 186, 17.  DOI. ADS. ADSCrossRefGoogle Scholar
  16. Koskela, J.S., Virtanen, I.I., Mursula, K.: 2017, Comparing coronal and heliospheric magnetic fields over several solar cycles. Astrophys. J. 835, 63.  DOI. ADS. ADSCrossRefGoogle Scholar
  17. Makarov, V.I., Fatianov, M.P., Sivaraman, K.R.: 1983, Poleward migration of the magnetic neutral line and the reversal of the polar fields on the Sun. I – Period 1945 – 1981. Solar Phys. 85, 215.  DOI. ADS. ADSCrossRefGoogle Scholar
  18. Maliniemi, V., Asikainen, T., Mursula, K.: 2014, Spatial distribution of northern hemisphere winter temperatures during different phases of the solar cycle. J. Geophys. Res. 119, 9752.  DOI. ADS. Google Scholar
  19. Mansurov, S.M.: 1970, New evidence of a relationship between magnetic fields in space and on Earth. Geomagn. Aeron. 9, 622. ADS. ADSGoogle Scholar
  20. McIntosh, S.W., Leamon, R.J., Gurman, J.B., Olive, J.-P., Cirtain, J.W., Hathaway, D.H., Burkepile, J., Miesch, M., Markel, R.S., Sitongia, L.: 2013, Hemispheric asymmetries of solar photospheric magnetism: radiative, particulate, and heliospheric impacts. Astrophys. J. 765, 146.  DOI. ADS. ADSCrossRefGoogle Scholar
  21. Mursula, K., Hiltula, T.: 2003, Bashful ballerina: southward shifted heliospheric current sheet. Geophys. Res. Lett. 30(22), 2135.  DOI. ADS. ADSCrossRefGoogle Scholar
  22. Mursula, K., Hiltula, T.: 2004, Systematically asymmetric heliospheric magnetic field: evidence for a quadrupole mode and non-axisymmetry with polarity flip-flops. Solar Phys. 224, 133.  DOI. ADS. ADSCrossRefGoogle Scholar
  23. Mursula, K., Hiltula, T., Zieger, B.: 2002, Latitudinal gradients of solar wind speed around the ecliptic: systematic displacement of the streamer belt. Geophys. Res. Lett. 29, 28.  DOI. ADS. CrossRefGoogle Scholar
  24. Mursula, K., Virtanen, I.: 2011, The last dance of the bashful ballerina? Astron. Astrophys. 525, L12.  DOI. ADS. ADSCrossRefGoogle Scholar
  25. Mursula, K., Zieger, B.: 2001, Long-term North–South asymmetry in solar wind speed inferred from geomagnetic activity: a new type of century-scale solar oscillation? Geophys. Res. Lett. 28, 95.  DOI. ADS. ADSCrossRefGoogle Scholar
  26. Norton, A.A., Charbonneau, P., Passos, D.: 2014, Hemispheric coupling: comparing dynamo simulations and observations. Space Sci. Rev. 186, 251.  DOI. ADS. ADSCrossRefGoogle Scholar
  27. Norton, A.A., Gallagher, J.C.: 2010, Solar-cycle characteristics examined in separate hemispheres: phase, gnevyshev gap, and length of minimum. Solar Phys. 261, 193.  DOI. ADS. ADSCrossRefGoogle Scholar
  28. Pishkalo, M.I.: 2006, Reconstruction of the heliospheric current sheet tilts using sunspot numbers. Solar Phys. 233, 277.  DOI. ADS. ADSCrossRefGoogle Scholar
  29. Rosenberg, R.L., Coleman, P.J. Jr.: 1969, Heliographic latitude dependence of the dominant polarity of the interplanetary magnetic field. J. Geophys. Res. 74, 5611.  DOI. ADS. ADSCrossRefGoogle Scholar
  30. Sanderson, T.R., Appourchaux, T., Hoeksema, J.T., Harvey, K.L.: 2003, Observations of the Sun’s magnetic field during the recent solar maximum. J. Geophys. Res. 108, 1035.  DOI. ADS. CrossRefGoogle Scholar
  31. Schulz, M.: 1973, Interplanetary sector structure and the helliomagnetic equator. Astrophys. Space Sci. 24, 371.  DOI. ADS. ADSCrossRefGoogle Scholar
  32. Simpson, J.A., Zhang, M., Bame, S.: 1996, A solar polar North-South asymmetry for cosmic-ray propagation in the heliosphere: the ULYSSES pole-to-pole rapid transit. Astrophys. J. Lett. 465, L69.  DOI. ADS. ADSCrossRefGoogle Scholar
  33. Smith, E.J., Balogh, A.: 2008, Decrease in heliospheric magnetic flux in this solar minimum: recent Ulysses magnetic field observations. Geophys. Res. Lett. 35, L22103.  DOI. ADS. ADSCrossRefGoogle Scholar
  34. Smith, E.J., Jokipii, J.R., Kóta, J., Lepping, R.P., Szabo, A.: 2000, Evidence of a North–South asymmetry in the heliosphere associated with a southward displacement of the heliospheric current sheet. Astrophys. J. 533, 1084.  DOI. ADS. ADSCrossRefGoogle Scholar
  35. Spörer, F.W.G., Maunder, E.W.: 1890, Prof. Spörer’s researches on Sun-spots. Mon. Not. Roy. Astron. Soc. 50, 251.  DOI. ADS. ADSGoogle Scholar
  36. Sun, X., Hoeksema, J.T., Liu, Y., Zhao, J.: 2015, On polar magnetic field reversal and surface flux transport during solar cycle 24. Astrophys. J. 798, 114.  DOI. ADS. ADSCrossRefGoogle Scholar
  37. Svalgaard, L.: 1968, Sector structure of the interplanetary magnetic field and daily variation of the geomagnetic field at high latitudes. Geophys. papers r-6, Danish Met. Inst., Copenhagen, Denmark. Google Scholar
  38. Svalgaard, L., Hannah, I.G., Hudson, H.S.: 2011, Flaring solar Hale sector boundaries. Astrophys. J. 733, 49.  DOI. ADS. ADSCrossRefGoogle Scholar
  39. Svalgaard, L., Kamide, Y.: 2013, Asymmetric solar polar field reversals. Astrophys. J. 763, 23.  DOI. ADS. ADSCrossRefGoogle Scholar
  40. Svalgaard, L., Wilcox, J.M.: 1976, The Hale solar sector boundary. Solar Phys. 49, 177.  DOI. ADS. ADSCrossRefGoogle Scholar
  41. Temmer, M., Rybák, J., Bendík, P., Veronig, A., Vogler, F., Otruba, W., Pötzi, W., Hanslmeier, A.: 2006, Hemispheric sunspot numbers \(\{R_{n}\}\) and \(\{R_{s}\}\) from 1945 – 2004: catalogue and N–S asymmetry analysis for solar cycles 18 – 23. Astron. Astrophys. 447, 735.  DOI. ADS. ADSCrossRefGoogle Scholar
  42. Virtanen, I.I., Mursula, K.: 2010, Asymmetry of solar polar fields and the southward shift of HCS observed by Ulysses. J. Geophys. Res. 115, A09110.  DOI. ADS. ADSCrossRefGoogle Scholar
  43. Virtanen, I.I., Mursula, K.: 2014, North–South asymmetric solar cycle evolution: signatures in the photosphere and consequences in the corona. Astrophys. J. 781, 99.  DOI. ADS. ADSCrossRefGoogle Scholar
  44. Vokhmyanin, M.V., Ponyavin, D.I.: 2013, Sector structure of the interplanetary magnetic field in the nineteenth century. Geophys. Res. Lett. 40, 3512.  DOI. ADS. ADSCrossRefGoogle Scholar
  45. Wang, Y.-M., Robbrecht, E.: 2011, Asymmetric sunspot activity and the southward displacement of the heliospheric current sheet. Astrophys. J. 736, 136.  DOI. ADS. ADSCrossRefGoogle Scholar
  46. Wang, Y.-M., Robbrecht, E., Sheeley, N.R. Jr.: 2009, On the weakening of the polar magnetic fields during solar cycle 23. Astrophys. J. 707, 1372.  DOI. ADS. ADSCrossRefGoogle Scholar
  47. Wilcox, J.M., Howard, R.: 1968, A large-scale pattern in the solar magnetic field. Solar Phys. 5, 564.  DOI. ADS. ADSCrossRefGoogle Scholar
  48. Wilcox, J.M., Ness, N.F.: 1965, Quasi-stationary corotating structure in the interplanetary medium. J. Geophys. Res. 70, 5793.  DOI. ADS. ADSCrossRefGoogle Scholar
  49. Zhao, X.P., Hoeksema, J.T., Scherrer, P.H.: 2005, Prediction and understanding of the North–South displacement of the heliospheric current sheet. J. Geophys. Res. 110, 10101.  DOI. ADS. CrossRefGoogle Scholar
  50. Zieger, B., Mursula, K.: 1998, Annual variation in near-Earth solar wind speed: evidence for persistent North–South asymmetry related to solar magnetic polarity. Geophys. Res. Lett. 25, 841.  DOI. ADS. ADSCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media B.V. 2017

Authors and Affiliations

  • Tibebu Getachew
    • 1
  • Ilpo Virtanen
    • 1
  • Kalevi Mursula
    • 1
  1. 1.ReSoLVE Centre of Excellence, Space Climate Research UnitUniversity of OuluOuluFinland

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