The most striking feature of the Sun's magnetic field is its cyclic behaviour. The number of sunspots, which are dark regions of strong magnetic field on the Sun's surface, varies with a period of about 11 years. Superposed on this cycle are secular changes that occur on timescales of centuries and events like the Maunder minimum in the second half of the seventeenth century, when there were very few sunspots1,2. A part of the Sun's magnetic field reaches out from the surface into interplanetary space, and it was recently discovered3 that the average strength of this interplanetary field has doubled in the past 100 years. There has hitherto been no clear explanation for this doubling. Here we present a model describing the long-term evolution of the Sun's large-scale magnetic field, which reproduces the doubling of the interplanetary field. The model indicates that there is a direct connection between the length of the sunspot cycle and the secular variations.
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Ribes, J. C. & Nesme-Ribes, E. The solar sunspot cycle in the Maunder minimum AD1645 to AD1715. Astron. Astrophys. 276, 549–563 (1993).
Beer, J., Blinov, A., Bonani, G., Hofmann, H. J. & Finkel, R. C. Use of 10Be in polar ice to trace the 11-year cycle of solar activity. Nature 347, 164–166 (1990).
Lockwood, M., Stamper, R. & Wild, M. N. A doubling of the Sun's coronal magnetic field during the past 100 years. Nature 399, 437– 439 (1999).
Harvey, K. L. & Zwaan, C. Properties and emergence of bipolar active regions. Sol. Phys. 148, 85– 118 (1993).
Sheeley, N. R. in The Solar Cycle (ed. Harvey, K. L.) 1–13 (Astronomical Society of the Pacific, ASP Conf. Series Vol. 27, San Francisco, 1992).
Wang, Y. M. & Sheeley, N. R. The rotation of photospheric magnetic fields: A random walk transport model. Astrophys. J. 430, 399–412 (1994).
Wang, Y.-M., Lean, J. & Sheeley, N. R. The long-term variation of the Sun's open magnetic flux. Geophys. Res. Lett. 27, 505– 508 (2000).
Wang, Y.-M., Sheeley, N. R. & Lean, J. Understanding the evolution of the Sun's open magnetic flux. Geophys. Res. Lett. 27, 621– 624 (2000).
Schrijver, C. J. et al. Large-scale coronal heating by the small-scale magnetic field of the Sun. Nature 394, 152– 154 (1998).
Howard, R. & Labonte, B. J. Surface magnetic fields during the solar activity cycle. Sol. Phys. 74, 131–145 (1981).
Harvey, K. L. in Solar Surface Magnetism (eds Rutten, R. J. & Schrijver, C. J.) 347–363 (Kluwer, Dordrecht, 1994).
Livingston, W. C., Harvey, J., Slaughter, C. & Trumbo, D. Solar magnetograph employing integrated diode arrays. Appl. Opt. 15, 40–52 ( 1976).
Schrijver, C. J. & Harvey, K. L. The photospheric magnetic flux budget. Sol. Phys. 150, 1– 18 (1994).
Chapman, G. A., Cookson, A. M. & Dobias, J. J. Solar variability and the relation of facular to sunspot areas during solar cycle 22. Astrophys. J. 482, 541–545 (1997).
Fligge, M., Solanki, S. K., Unruh, Y. C., Fröhlich, C. & Wehrli, C. A model of solar total and spectral irradiance variations. Astron. Astrophys. 355, 709–718 (1998).
Dicke, R. H. Solar luminosity and the sunspot cycle. Nature 280, 24–27 (1979).
Hoyng, P. Is the solar cycle timed by a clock? Sol. Phys. 169 , 253–264 (1996).
Wang, Y. M. & Sheeley, N. R. Solar implications of ULYSSES interplanetary field measurements. Astrophys. J. 447 , L143–L146 (1995).
Wilson, P. R., Altrock, R. C., Harvey, K. L., Martin, S. F. & Snodgrass, H. B. The extended solar activity cycle. Nature 333, 748– 750 (1988).
Harvey, K. L. in The Solar Cycle (ed. Harvey, K. L.) 335–367 (Astronomical Society of the Pacific, ASP Conf. Series Vol. 27, San Francisco, 1992).
Friis-Christensen, E. & Lassen, K. Length of the solar cycle: An indicator of solar activity closely associated with climate. Science 254, 698–700 ( 1991).
Svensmark, H. & Friis-Christensen, E. Variation of cosmic ray flux and global cloud coverage—a missing link in solar-climate relationships. J. Atmos. Terr. Phys. 59, 1225– 1232 (1997).
Svensmark, H. Influence of cosmic rays on Earth's climate. Phys. Rev. Lett. 81, 5027–5030 (1998).
Scherrer, P. H. et al. The Solar Oscillations Investigation—Michelson Doppler Imager. Sol. Phys. 162, 129– 188 (1995).
J. Beer and M. Lockwood provided the 10Be record and the record of the reconstructed interplanetary magnetic field, respectively. We are grateful to K. Schrijver for comments on this paper.
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Solanki, S., Schüssler, M. & Fligge, M. Evolution of the Sun's large-scale magnetic field since the Maunder minimum . Nature 408, 445–447 (2000). https://doi.org/10.1038/35044027
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