Solar Variability

doi:10.1017/9781108290135.019

18 - Solar Variability

Causes, Current Understanding, Prospects for the Future

from Part V - Magnetic Fields beyond the Earth and beyond Today

Published online by Cambridge University Press: 25 October 2019

Edited by

Andrew Yau and

Mioara Mandea: Affiliation:
Centre National d'études Spatiales, France
Monika Korte: Affiliation:
GeoforschungsZentrum, Helmholtz-Zentrum, Potsdam
Andrew Yau: Affiliation:
University of Calgary
Eduard Petrovsky: Affiliation:
Academy of Sciences of the Czech Republic, Prague

Book contents

Get access

Summary

Solar variability is the origin of space weather. Variations in the rate and kind of energetic output from the Sun cause the variability in the Earth’s space environment, generally termed space weather. The physics of the causes and phenomenology of the evolving solar energetic output has become a major topic of observational and theoretical research. The major components of solar variability are reviewed, together with what are understood to be outstanding questions. Understanding the origin of solar wind streams and their dependence on solar conditions contributes to the predictability of interplanetary processes that affect the Earth’s space environment and are primary drivers of space weather phenomena. The phenomenology of space weather effects resulting from variable solar and interplanetary conditions is well documented, with increasing details uncovered, but the causal processes are less so, as evidenced by the limits of predictability of space weather drivers. Future emphasis must be on improving models, both by the details and resolution that can be achieved and a clearer quantitative understanding of causal relationships, against a background of the essentially stochastic nature of all solar and interplanetary phenomena.

Keywords

Solar variability solar wind space weather Earth’s space environment

Information

Type: Chapter
Information: Geomagnetism, Aeronomy and Space Weather
A Journey from the Earth's Core to the Sun
, pp. 286 - 311

DOI: https://doi.org/10.1017/9781108290135.019 [Opens in a new window]

Publisher: Cambridge University Press

Print publication year: 2019

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Book purchase

Temporarily unavailable

References

Abbo, L., Ofman, L., Antiochos, S. K., Hansteen, V. H., Harra, L., Ko, Y.-K., Lapenta, G., Li, B., Riley, P., Strachan, L., von Steiger, R. & Wang, Y.-M. Slow solar wind: Observations and modeling, Space Sci. Rev., 201, 55–108 (2016). doi: 10.1007/s11214-016-0264-1CrossRef Google Scholar

Altschuler, M. D. & Newkirk, G. Jr. Magnetic fields and the structure of the solar corona I: Methods of calculating coronal fields, Sol. Phys., 9, 131–49 (1969).Google Scholar

Aulanier, G., Török, T., Démoulin, P. & DeLuca, E. E. Formation of torus-unstable flux ropes and electric currents in erupting sigmoids, Astrophys. J., 708, 314–33 (2010). doi: 10.1088/0004-637X/708/1/314Google Scholar

Babcock, H. D. The Sun’s polar magnetic field, Astrophys. J., 130, 364–5 (1959). doi: 10.1086/146726Google Scholar

Babcock, H. W. The topology of the Sun’s magnetic field and the 22-year cycle, Astrophys. J., 133, 572–87 (1961).Google Scholar

Balogh, A. & Erdõs, G. The heliospheric magnetic field, Space Sci. Rev., 176, 177–215 (2013). doi: 10.1007/s11214-011-9835-3CrossRef Google Scholar

Balogh, A. & Smith, E. J. The heliospheric magnetic field at solar maximum: Ulysses observations, Space Sci. Rev., 97, 147–60 (2001). doi: 10.1023/A:101185490CrossRef Google Scholar

Balogh, A. & Thompson, M. J. Introduction to solar magnetism: The early years, Space Sci. Rev., 144, 1–14 (2009). doi: 10.1007/s11214-009-9493-xGoogle Scholar

Balogh, A., Hudson, H. S., Petrovay, K. & von Steiger, R. Introduction to the solar activity cycle: Overview of causes and consequences, Space Sci. Rev., 186, 1–15 (2014). doi: 10.1007/s11214-014–0125CrossRef Google Scholar

Barnes, G., Leka, K. D., Schrijver, C. J., Colak, T., Qahwaji, R., Ashamari, O. W., Yuan, Y., Zhang, J., McAteer, R. T. J., Bloomfield, D. S., Higgins, P. A., Gallagher, P. T., Falconer, D. A., Georgoulis, M. K., Wheatland, M. S., Balch, C., Dunn, T. & Wagner, E. L. A comparison of flare forecasting methods. I. Results from the ‘All-Clear’ workshop, Astrophys. J., 829(2), Article 89 (2016). doi: 10.3847/0004-637X/829/2/89Google Scholar

Behannon, K. W. Heliocentric distance dependence of the interplanetary magnetic field, Rev. Geophys. Space Phys., 16, 125–45 (1978). doi: 10.1029/RG016i001p00125CrossRef Google Scholar

Berger, M. A. Introduction to magnetic helicity, Plasma Phys. Control. Fusion, 41, B167–75 (1999). doi: 10.1088/0741-3335/41/12B/312Google Scholar

Berger, M. Magnetic helicity conservation, Highlights Astron., 13, 85–8 (2005). doi: 10.1017/S1539299600015148Google Scholar

Blackman, E. G. Magnetic helicity and large scale magnetic fields: A primer, Space Sci. Rev., 188, 59–91 (2015). doi: 10.1007/s11214-014-0038-6Google Scholar

Brueckner, G. E., Howard, R. A., Koomen, M. J., et al. The Large Angle Spectroscopic Coronagraph (LASCO), Sol. Phys., 162, 357–402 (1995). doi: 10.1007/BF00733434Google Scholar

Brun, A. S., Miesch, M. S. & Toomre, J., Global-scale turbulent convection and magnetic dynamo action in the solar envelope, Astrophys. J., 614, 1073–98 (2004). doi: 10.1086/423835Google Scholar

Brun, A. S., Browning, M. K., Dikpati, M., Hotta, H. & Strugarek, A. Recent advances on solar global magnetism and variability, Space Sci. Rev., 196, 101–36 (2015). doi: 10.1007/s11214-013-0028-0CrossRef Google Scholar

Cameron, R. H. & Schüssler, M. The crucial role of surface magnetic fields for the solar dynamo, Science, 347, 1333–5 (2015). doi: 10.1126/science.1261470Google Scholar

Cameron, R. H. & Schüssler, M. An update of Leighton’s solar dynamo model, Astron. Astrophys., 599, Article A52 (2017). doi: 10.1051/0004-6361/201629746Google Scholar

Cameron, R. H., Dasi-Espuig, M., Jiang, J., Işik, E., Schmidt, D. & Schüssler, M. Limits to solar cycle predictability: Cross-equatorial flux plumes, Astron. Astrophys., 557, Article A141 (2013). doi: 10.1051/0004-6361/201321981Google Scholar

Cameron, R. H., Jiang, J., Schüssler, M. & Gizon, L. Physical causes of solar cycle amplitude variability, J. Geophys. Res., 119, 680–88 (2014). doi: 10.1002/2013JA019498CrossRef Google Scholar

Charbonneau, P. Where is the solar dynamo? J. Phys. Conf. Ser., 440, Article 012014 (2013). doi: 10.1088/1742-6596/440/1/012014Google Scholar

Charbonneau, P. Solar dynamo theory, Ann. Rev. Astron. Astrophys., 52, 251–90 (2014). doi: 10.1146/annurev-astro-081913-040012Google Scholar

Chen, F., Rempel, M. & Fan, Y., Emergence of magnetic flux generated in a solar convective dynamo. I: Formation of sunspots and active regions, and origin of their asymmetries, Astrophys. J., 846, Article 149 (2017). doi: 10.3847/1538-4357/aa85a0Google Scholar

Chen, Y., Liu, L. & Wan, W., Does the F_10.7 index correctly describe solar EUV flux during the deep solar minimum of 2007–2009? J. Geophys. Res., 116, Article A04304 (2011). doi: 10.1029/2010JA016301Google Scholar

Cheung, M. C. M., van Driel-Gesztelyi, L., Martínez Pillet, V. & Thompson, M. J., The life cycle of active region magnetic fields, Space Sci. Rev., 210, 317–49 (2017). doi: 10.1007/s11214-016-0259-yGoogle Scholar

Clette, F., Svalgaard, L., Vaquero, J. M. & Cliver, E. W. Revisiting the sunspot number: A 400-year perspective on the solar cycle, Space Sci. Rev., 186(1–4), 35–103 (2014). doi: 10.1007/s11214-014-0074-2Google Scholar

Choudhuri, A. R. Starspots, stellar cycles and stellar flares: Lessons from solar dynamo models, Sci. Chin. Phys. Mech. Astron., 60, Article 1:019601 (2017). doi: 10.1007/s11433-016-0413-7Google Scholar

Cranmer, S. R. Coronal holes and the high speed solar wind, Space Sci. Rev., 101, 229–94 (2002). doi: 10.1023/A:1020840004535Google Scholar

Cranmer, S. R., Coronal holes, Living Rev. Sol. Phys., 6, Article 3 (2009). doi: 10.12942/lrsp-2009-3Google Scholar

Cranmer, S. R., Gibson, S. E. & Riley, P. Origins of the ambient solar wind: Implications for space weather, Space Sci. Rev., 212, 1345–84 (2017). doi: 10.1007/s11214-017-0416-yGoogle Scholar

Dasi-Espuig, M., Solanki, S. K., Krivova, N. A., Cameron, R. & Peñuela, T. Sunspot group tilt angles and the strength of the solar cycle, Astron. Astrophys., 518, Article A7 (2010). doi: 10.1051/0004-6361/201014301Google Scholar

Demoulin, P. & Berger, M. A. Magnetic energy and helicity fluxes at the photospheric level, Sol. Phys., 215, 203–15 (2003). doi: 10.1023/A:1025679813955Google Scholar

de Toma, G., Chapman, G. A., Cookson, A. M. & Preminger, D. Temporal stability of sunspot umbral intensities: 1986–2012, Astrophys. J. Lett., 771, Article L22 (2013). doi: 10.1088/2041-8205/771/2/L22CrossRef Google Scholar

Deubner, F.-L. & Gough, D. Helioseismology: Oscillations as a diagnostic of the solar interior, Annu. Rev. Astron. Astrophys., 22, 593–619 (1984). doi: 10.1146/annurev.aa.22.090184.0031Google Scholar

Dikpati, M. & Gilman, P. A. Flux-transport solar dynamos, Space Sci. Rev., 144, 67–75 (2009). doi: 10.1007/s11214-008-9484-3Google Scholar

Dudok de Wit, T., Bruinsma, S. & Shibasaki, K. Synoptic radio observations as proxies for upper atmosphere modelling, J. Space Weather Space Clim., 4, Article A06 (2015). doi: 10.1051/swsc/2014003Google Scholar

Dudok de Wit, T., Kopp, G., Fröhlich, C. & Schöll, M. Methodology to create a new Total Solar Irradiance record: Making a composite out of multiple data records, Geophys. Res. Lett., 44, 1196–1203 (2017). doi: 10.1002/2016GL071866Google Scholar

Ebert, R. W., McComas, D. J., Elliott, H. A., Forsyth, R. J. & Gosling, J. T. Bulk properties of the slow and fast solar wind and interplanetary coronal mass ejections measured by Ulysses: Three polar orbits of observations, J. Geophys. Res., 114, Article A01109 (2009). doi: 10.1029/2008JA013631CrossRef Google Scholar

Eddy, J. A. The Maunder minimum, Science, 192(4245), 1189–1202 (1976).CrossRef Google Scholar PubMed

Edmondson, J. K. On the role of interchange reconnection in the generation of the slow solar wind, Space Sci. Rev., 172, 209–25 (2012). doi: 10.1007/s11214-011-9767-yGoogle Scholar

Erdõs, G. & Balogh, A. Magnetic flux density measured in fast and slow solar wind streams, Astrophys J., 753, Article 130 (2012). doi: 10.1088/0004-637X/753/2/130.Google Scholar

Erdõs, G. & Balogh, A. Magnetic flux density in the heliosphere through several solar cycles, Astrophys. J., 781(1), Article 50 (2014). doi: 10.1088/0004-637X/781/1/50CrossRef Google Scholar

Fletcher, S. T., Broomhall, A.-M., Salabert, D., Basu, S., Chaplin, W. J., Elsworth, Y., Garcia, R. A. & New, R. A seismic signature of a second dynamo? Astophys. J. Lett., 718, L19–22 (2010). doi: 10.1088/2041-8205/718/1/L19Google Scholar

Fox, N. J., Velli, M. C., Bale, S. D., Decker, R., Driesman, A., Howard, R. A., Kasper, J. C., Kinnison, J., Kusterer, M., Lario, D., Lockwood, M. K., McComas, D. J., Raouafi, N. E. & Szabo, A. The Solar Probe Plus mission: Humanity’s first visit to our star, Space Sci. Rev., 204, 7–48 (2016). doi: 10.1007/s11214-015-0211-6Google Scholar

Fröhlich, C. Solar irradiance variability since 1978: Revision of the PMOD composite during Solar Cycle 21, Space Sci. Rev., 125, 53–65 (2006). doi: 10.1007/s11214-006-9046-5.Google Scholar

Fröhlich, C. Total solar irradiance: What have we learned from the last three cycles and the recent minimum? Space Sci. Rev., 176, 237–52 (2013). doi: 10.1007/s11214-011-9780-1.Google Scholar

Geiss, J., Gloeckler, G. & von Steiger, R. Origin of the solar wind from composition data, Space Sci. Rev., 72, 49–60 (1995). doi: 10.1007/BF00768753Google Scholar

Girazian, Z. & Withers, P. An empirical model of the extreme ultraviolet solar spectrum as a function of the F_10.7 index, J. Geophys. Res., 120, 6779–94 (2015). doi: 10.1002/2015JA021436.Google Scholar

Gloeckler, G., Geiss, J., Balsiger, H., Bedini, P., Cain, J. C., Fischer, J., Fisk, L. A., Galvin, A. B., Gliem, F., Hamilton, D. C., Hollweg, J. V., Ipavich, F. M., Joos, R., Livi, S., Lundgren, R. A., Mall, U., McKenzie, J. F., Ogilvie, K. W., Ottens, F., Rieck, W., Tums, E. O., von Steiger, R., Weiss, W. & Wilken, B. The solar wind ion composition spectrometer, Astron. Astrophys. Suppl. Ser., 92, 267 (1992).Google Scholar

Gopalswamy, N., Xie, H., Akiyama, S., Mäkelä, P., Yashiro, S. & Michalek, G. The peculiar behavior of halo coronal mass ejections in Solar Cycle 24, Astrophys. J. Lett., 804(1), Article L23 (2015). doi: 10.1088/2041-8205/804/1/L23Google Scholar

Gosling, J. T. Corotating and transient solar wind flows in three dimensions, Annu. Rev. Astron. Astrophys., 34, 35–73 (1996). doi: 10.1146/annurev.astro.34.1.35Google Scholar

Green, L. M., Török, T., Vršnak, B., Manchester, B. IV & Veronig, A. The origin, early evolution and predictability of solar eruptions, Space Sci. Rev., 214, Article 46 (2018). doi: 10.1007/s11214-017-0462-5Google Scholar

Haigh, J. D. The Sun and the Earth’s climate, Living Rev. Sol. Phys., 4, Article 2 (2007). doi: 10.12942/lrsp-2007-2Google Scholar

Hale, G. E., Ellerman, F., Nicholson, S. B. & Joy, A. H. The magnetic polarity of sunspots, Astrophys. J., 49, 153–78 (1919).Google Scholar

Hanasoge, S., Miesch, M. S., Roth, M., Schou, J., Schüssler, M. & Thompson, M. J. Solar dynamics, rotation, convection and overshoot, Space Sci. Rev., 196, 79–99 (2015). doi: 10.1007/s11214-015–0144–0Google Scholar

Hathaway, D. H. Solar cycle forecasting, Space Sci. Rev., 144, 401–12 (2009).Google Scholar

Hathaway, D. H. The solar cycle, Living Rev. Sol. Phys., 12, Article 4 (2015). doi: 10.1007/lrsp-2015-4Google Scholar

Hathaway, D. H. & Upton, L. The solar meridional circulation and sunspot cycle variability, J. Geophys. Res., 119, 3316–24 (2014). doi: 10.1002/2013JA019432Google Scholar

Hathaway, D. H. & Wilson, R. M. Geomagnetic activity indicates large amplitude for sunspot cycle 24, Geophys. Res. Lett., 33, L18101 (2006). doi: 10.1029/2006GL027053CrossRef Google Scholar

Hathaway, D. H., Wilson, R. M. & Reichmann, E. J. A synthesis of solar cycle predictions, J. Geophys. Res., 104, 22375–88 (1999). doi: 10.1029/1999JA900313Google Scholar

Hathaway, D. H., Wilson, R. M. & Reichmann, E. J. Group sunspot numbers: Sunspot cycle characteristics, Sol. Phys., 211, 357–70 (2002). doi: 10.1023/A:1022425402664CrossRef Google Scholar

Hess, P. & Colaninno, R. C. Comparing automatic CME detections in multiple LASCO and SECCHI catalogs, Astrophys. J., 836, Article 134 (2017). doi: 10.3847/1538-4357/aa5b85Google Scholar

Hoeksema, J. T., Wilcox, J. M. & Scherrer, P. H. Structure of the heliospheric current sheet in the early portion of Sunspot Cycle 21, J. Geophys. Res., 87, 10331–8 (1982). doi: 10.1029/JA087iA12p10331Google Scholar

Jiang, J. Solar-cycle precursors and predictions, in Solar and Astrophysical Dynamos and Magnetic Activity, ed. Kosovichev, A. G., de Gouveia Dal Pino, E. M. & Yan, Y., pp. 49–60, Proceedings IAU Symposium 294 (2013). doi: 10.1017/S1743921313002196Google Scholar

Jiang, J., Chatterjee, P. & Choudhuri, A. R. Solar activity forecast with a dynamo model, Mon. Not. R. Astron. Soc., 381, 1527–42 (2007). doi: 10.1111/j.1365-2966.2007.12267.xCrossRef Google Scholar

Jiang, J., Cameron, R. H., Schmitt, D. & Işık, E. Modelling solar cycles 15 to 21 using a flux transport dynamo, Astron. Astrophys., 553, Article A128 (2013). doi: 10.1051/0004-6361/201321145Google Scholar

Jiang, J., Hathaway, D. H., Cameron, R. H., Solanki, S. K., Gizon, L. & Upton, L. Magnetic flux transport at the solar surface, Space Sci. Rev., 186, 491–523 (2014). doi: 10.1007/s11214-014-0083-1Google Scholar

Kepko, L., Viall, N. M., Antiochos, S. K., Lepri, S. T., Kasper, J. C. & Weberg, M. Implications of L1 observations for slow solar wind formation by solar reconnection, Geophys. Res. Lett., 43, 4089–97 (2017). doi: 10.1002/2016GL068607Google Scholar

Kilpua, E. K. J., Madjarska, M. S., Karna, N., Wiegelmann, T., Farrugia, C., Yu, W. & Andreeova, K. Sources of the slow solar wind during the Solar Cycle 23/24 minimum, Sol. Phys., 291, 2441–56 (2016). doi: 10.1007/s11207-016-0979-xGoogle Scholar

Kilpua, E. K. J., Balogh, A., von Steiger, R. & Liu, Y. D. Geoeffective properties of solar transients and stream interaction regions, Space Sci. Rev., 212, 1271–1314 (2017). doi: 10.1007/s11214-017-0411-3Google Scholar

Kopp, G. Magnitudes and timescales of total solar irradiance variability, J. Space Weather Space Clim., 6, Article A30 (2016). doi: 10.1051/swsc/2016025Google Scholar

Korhonen, H. Properties of stellar activity cycles, Proc. IAU, 11(A29A), 354–9 (2016). doi: 10.1017/S1743921316003276Google Scholar

Krivova, N. A., Solanki, S. K. & Floyd, L. Reconstruction of solar UV irradiance in cycle 23, Astron. Astrophys., 452, 631–9 (2006). doi: 10.1051/0004-6361:20064809Google Scholar

Lean, J. L., Wang, Y.-M. & Sheeley, N. R. Jr. The effect of increasing solar activity on the Sun’s total and open magnetic flux during multiple cycles: Implications for solar forcing of climate, Geophys. Res. Lett., 29(24), Article 2224 (2002). doi: 10.1029/2002GL015880Google Scholar

Leighton, R. B. A magneto-kinematic model of the solar cycle, Astrophys. J., 156, 1–26 (1969). doi: 10.1086/149943Google Scholar

Lemerle, A. & Charbonneau, P. A coupled 2 × 2D Babcock-Leighton solar dynamo model. II. Reference dynamo solutions, Astrophys. J., 834(2), Article 133 (2017). doi: 10.3847/1538-4357/834/2/133Google Scholar

Li, K. J., Wang, J. X., Xiong, S. Y., Liang, H. F., Yun, H. S. & Gu, X. M. Regularity of the north-south asymmetry of solar activity, Astron. Astrophys., 383, 648–52 (2002). doi: 10.1051/0004-6361:20011799Google Scholar

Linker, J. A., Mikic, Z., Biesecker, D. A., Forsyth, R. J., Gibson, S. E., Lazarus, A. J., Lecinski, V., Riley, P., Szabo, A. & Thompson, B. J. Magnetohydrodynamic modeling of the solar corona during Whole Sun Month, J. Geophys. Res., 104, 9809–30 (1999). doi: 10.1029/1998JA900159Google Scholar

Linker, J. A., Caplan, R. M., Downs, C., Riley, P., Mikic, Z., Lionello, R. Henney, C. J., Arge, C. N., Liu, Y., Derosa, M. L., Yeates, A. & Owens, M. J. The open flux problem, Astrophys. J., 848(1), Article 70 (2017). doi: 10.3847/1538-4357/aa8a70Google Scholar

Livingston, W., Penn, M. J. & Svalgaard, L. Decreasing sunspot magnetic fields explain unique 10.7 cm radio flux, Astrophys. J. Lett., 757, Article L8 (2012). doi: 10.1088/2041-8205/757/1/L8Google Scholar

Lockwood, M., Owens, M., Hawkins, E., Jones, G. S. & Usoskin, I. Frost fairs, sunspots and the Little Ice Age, Astron. Geophys., 83(2), 17–23 (2017). doi: 10.1093/astrogeo/atx057Google Scholar

Lugaz, N., Temmer, M., Wang, Y. & Farrugia, C. J. The interaction of successive coronal mass ejections: A review, Sol. Phys., 292(4), Article 64 (2017). doi: 10.1007/s11207-017-1091-6Google Scholar

Luhmann, J. G., Lee, C. O., Li, Y., Arge, C. N., Galvin, A. B., Simunac, K., Russell, C. T., Howard, R. A. & Petrie, G. Solar wind sources in the late declining phase of Cycle 23: Effects of the weak solar polar field on high speed streams, Sol. Phys., 256, 285–305 (2009). doi: 10.1007/s11207-009-9354-5Google Scholar

Manchester, W., IV, Kilpua, E. K. J., Liu, Y. D., Lugaz, N., Riley, P., Török, T. & Vršnak, B. The physical processes of CME/ICME evolution, Space Sci. Rev., 212, 1159–1219 (2017). doi: 10.1007/s11214-017-0394-0Google Scholar

Martin, S. F. Conditions for the formation and maintenance of filaments, Sol. Phys., 182, 107–37 (1998). doi: 10.1023/A:100502681Google Scholar

Maunder, E. W. Note on the distribution of sunspots in heliographic latitude, 1874 to 1902, Mon. Nat. R. Astron. Soc., 64, 747–61 (1904).Google Scholar

McComas, D. J., Elliott, H. A., Schwadron, N. A., Gosling, G. T., Skoug, R. M. & Goldstein, B. E. The three-dimensional solar wind around solar maximum, Geophys. Res. Lett., 30(10), 1517–20 (2003). doi: 10.1029/2003GL017136Google Scholar

McComas, D. J., Velli, M., Lewis, W. S., Acton, L. W., Balat-Pichelin, M., Bothmer, V., Dirling, R. B., Feldman, W. C., Gloeckler, G., Habbal, S. R., Hassler, D. M., Mann, I., Matthaeus, W. H., McNutt, R. L., Mewaldt, R. A., Murphy, N., Ofman, L., Sittler, E. C., Smith, C. W. & Zurbuchen, T. H. Understanding coronal heating and solar wind acceleration: Case for in situ near-Sun measurements, Rev. Geophys., 45(1), Article RG1004 (2007). doi: 10.1029/2006RG000195Google Scholar

Melrose, D. B. Current-driven flare and CME models, J. Geophys. Res., 122, 7963–78 (2017). doi: 10.1002/2017JA024035CrossRef Google Scholar

Miralles, M. P., Cranmer, S. R. & Kohl, J. L. Low-latitude coronal holes during solar maximum, Adv. Space Res., 33, 696–700 (2004). doi: 10.1016/S0273-1177(03)00239-4Google Scholar

Mordvinov, A. V., Pevtsov, A. A., Bertello, L. & Petrie, G. J. D. The reversal of the Sun’s magnetic field in Cycle 24, Sol. Terr. Phys., 2(1), 3–18 (2016). doi: 10.12737/19856Google Scholar

Muñoz-Jaramillo, A., Balmaceda, L. A. & DeLuca, E. E. Using the dipolar and quadrupolar moments to improve solar-cycle predictions based on the polar magnetic fields, Phys. Rev. Lett., 111, Article 041106 (2013). doi: 10.1103/PhysRevLett.111.041106Google Scholar

Muraközy, J. & Ludmány, A. North-south differences of solar cycles, Centr. Eur. Astrophys. Bull., 34, 99–107 (2010).Google Scholar

Murray, S. A., Bingham, S., Sharpe, M. & Jackson, D. R. Flare forecasting at the Met Office Space Weather Operations Centre, Space Weather, 15, 577–88 (2017). doi: 10.1002/2016SW001579Google Scholar

Nagovitsyn, Y. A. & Pevtsov, A. A. On the presence of two populations of sunspots, Astrophys. J., 833, Article 94 (2016). doi: 10.3847/1538-4357/833/1/94Google Scholar

Nagovitsyn, Y. A., Pevtsov, A. A. & Osipova, A. A. Long-term variations in sunspot magnetic field–area relation, Astron. Nachr., 338, 26–34 (2017). doi: 10.1002/asna.201613035Google Scholar

Neugebauer, M. & Snyder, C. W. Solar plasma experiment, Science, 138, 1095–7 (1962).Google Scholar

Norton, A. A., Charbonneau, P. & Passos, D. Hemispheric coupling: Comparing dynamo simulations and observations, Space Sci. Rev., 186, 251–83 (2014). doi: 10.1007/s11214-014-0100-4Google Scholar

Odstrčil, D. Modeling 3-D solar wind structure, Adv. Space Res., 32, 497–506 (2003). doi: 10.1016/S0273-1177(03)00332-6Google Scholar

Owens, M. J. & Forsyth, R. J. The heliospheric magnetic field, Living Rev. Sol. Phys., 10(5), 1–52 (2013). doi: 10.12942/lrsp-2013-5Google Scholar

Owens, M. J., Lockwood, M. & Barnard, L. A. Coronal mass ejections are not coherent magnetohydrodynamic structures, Sci. Rep., 7, Article 4152 (2017). doi: 10.1038/s41598-017-04546-3Google Scholar

Owens, M. J. & Riley, P. Probabilistic solar wind forecasting using large ensembles of near-Sun conditions with a simple one-dimensional ‘upwind’ scheme, Space Weather, 15, 1461–74 (2017). doi: 10.1002/2017SW001679Google Scholar

Pariat, E., Leake, J. E., Valori, G., Linton, M. G., Zuccarello, F. P. & Dalmasse, K. Relative magnetic helicity as a diagnostic of solar eruptivity, Astron. Astrophys., 601, Article A125 (2017). doi: 10.1051/0004-6361/201630043Google Scholar

Park, S.-H., Kusano, K., Cho, K.-S., Chae, J., Bong, S.-C., Kumar, P., Park, S.-Y. Kim, Y.-H. & Park, Y.-D. Study of magnetic helicity injection in the active region NOAA 9236 producing multiple flare-associated coronal mass ejection events, Astrophys. J., 778(1), Article 13 (2013). doi: 10.1088/0004-637X/778/1/13Google Scholar

Parker, E. N. Dynamics of the interplanetary gas and magnetic fields, Astrophys. J., 128, 664–76 (1958).Google Scholar

Parker, E. N. Extension of the solar corona into interplanetary space, J. Geophys. Res., 64, 1675–81 (1959).Google Scholar

Pesnell, W. D. Solar cycle predictions, Sol. Phys., 281, 507–32 (2012). doi: 10.1007/s11207-012-9997-5Google Scholar

Pesnell, W. D. Predicting Solar Cycle 24 using a geomagnetic precursor pair, Sol. Phys., 289, 2317–31 (2014). doi: 10.1007/s11207-013-0470-xCrossRef Google Scholar

Pesnell, W. D. Predictions of solar cycle 24: How are we doing? Space Weather, 14, 10–21 (2016). doi: 10.1002/2015SW001304Google Scholar

Petrie, G. J. D. Evolution of active and polar photospheric magnetic fields during the rise of cycle 24 compared to previous cycles, Sol. Phys., 281, 577–98 (2012). doi: 10.1007/s11207-012-0117-3Google Scholar

Petrie, G. J. D. Solar magnetic activity cycles, coronal potential field models and eruption rates, Astrophys. J., 768, Article 12 (2013). doi: 10.1088/0004-637X/768/2/162Google Scholar

Petrie, G. J. D. On the enhanced coronal mass ejection detection rate since the Solar Cycle 23 polar field reversal, Astrophys. J., 812(1), Article 74 (2015). doi: 10.1088/0004-637X/812/1/74Google Scholar

Petrie, G. High-resolution vector magnetograms of the Sun’s poles from Hinode: Flux distributions and global coronal modelling, Sol. Phys., 292, Article 13 (2017). doi: 10.1007/s11207-016-1034-7Google Scholar

Petrie, G. J. D., Canou, A. & Amari, T. Nonlinear force-free and potential-field models of active-region and global coronal fields during the Whole Heliosphere Interval, Sol. Phys., 274, 163–94 (2011). doi: 10.1007/s11207-010-9687-0Google Scholar

Petrie, G. J. D., Petrovay, K. & Schatten, K. Solar polar fields and the 22-year activity cycle: Observations and models, Space Sci. Rev., 186, 325–57 (2014). doi: 10.1007/s11214-014-0064-4Google Scholar

Petrovay, K. Solar cycle prediction, Living Rev. Sol. Phys., 7, Article 6 (2010). doi: 10.12942/lrsp-2010-6#Google Scholar

Pipin, V. V. & Kosovichev, A. G. Dependence of stellar magnetic activity cycles on rotational period in a nonlinear solar-type dynamo, Astophys. J., 823(2), Article 133 (2016). doi: 10.3847/0004-637X/823/2/133Google Scholar

Priest, E. R., Longcope, D. W. & Janvier, M. Evolution of magnetic helicity during eruptive flares and coronal mass ejections, Sol. Phys., 291, 2017–36 (2016). doi: 10.1007/s11207-016-0962-6Google Scholar

Rezaei, R., Beck, C., Lagg, A., Borrero, J. M., Schmidt, W. & Collados, M. Variation in sunspot properties between 1999 and 2014, Astron. Astrophys., 578, Article A43 (2015). doi: 10.1051/0004-6361/201425557Google Scholar

Richardson, I. G. Solar wind stream interaction regions throughout the heliosphere, Liv. Rev. Sol. Phys., 15(1), Article 1 (2018). doi: 10.1007/s41116-017-0011-zGoogle Scholar

Richardson, J. D., Belcher, J. W., Lazarus, A. J. & Paularena, K. I. Statistical prpperties of the solar wind, AIP Conf. Proc., 382, 483–6 (1996). doi: 10.1063/1.51433Google Scholar

Riley, P., Linker, J. A., Mikic, Z., Lionello, R., Ledvina, S. A. & Luhmann, J. G. A comparison between global solar magnetohydrodynamic and potential field source surface model results, Astrophys. J., 653, 1510–16 (2006). doi: 10.1086/508565Google Scholar

Sadykov, V. M. & Kosovichev, A. G. Relationships between characteristics of the line-of-sight magnetic field and solar flare forecasts, Astrophys. J., 849, Article 148 (2017). doi: 10.3847/1538-4357/aa9119Google Scholar

Schatten, K. Fair space weather for solar cycle 24, Geophys. Res. Lett., 32, Article L21106 (2005). doi: 10.1029/2005GL024363Google Scholar

Schatten, K. H., Wilcox, J. M. & Ness, N. F. A model of the interplanetary and coronal magnetic fields, Sol. Phys., 6, 442–55 (1969).Google Scholar

Schmieder, B., Archontis, V. & Pariat, E. Magnetic flux emergence along the solar cycle, Space Sci. Rev., 186, 227–50 (2014). doi: 10.1007/s11214-014-0088-9Google Scholar

Schmieder, B., Aulanier, G. & Vršnak, B. Flare-CME models: An observational perspective (invited review), Sol. Phys., 290, 3457–86 (2015). doi: 10.1007/s11207-015-0712-1Google Scholar

Schonfeld, S. J., White, S. M., Henney, C. J., Arge, C. N. & McAteer, R. T. J. Coronal sources of the F10.7 radio flux, Astrophys. J., 808, Article 29 (2015). doi: 10.1088/0004-637X/808/1/29Google Scholar

Schrijver, C. J. The nonpotentiality of coronae of solar active regions, the dynamics of the surface magnetic field, and the potential for large flares, Astrophys. J., 820, Article 103 (2016). doi: 10.3847/0004-637X/820/2/103Google Scholar

Schrijver, C. J. & DeRosa, M. L. Photospheric and heliospheric magnetic fields, Sol. Phys., 212, 165–200 (2003). doi: 10.1023/A:1022908504100Google Scholar

Schrijver, C. J., De Rosa, M. L., Title, A. M. & Metcalf, T. R. The nonpotentiality of active-region coronae and the dynamics of the photospheric magnetic field, Astrophys. J., 628, 501–13 (2005). doi: 10.1086/430733Google Scholar

Schulz, M. Non-spherical source-surface model of the heliosphere: A scalar formulation, Ann. Geophys., 15, 1379–87 (1997). doi: 10.1007/s00585-997-1379-1Google Scholar

Severnyi, A. B. Nonstationary processes in solar flares as a manifestation of the pinch effect, Sov. Astron., 2, 310–25 (1958).Google Scholar

Sharykin, I. N., Sadykov, V. M., Kosovichev, A. G., Vargas-Dominguez, S. & Zimovets, I. V. Flare energy release in the lower solar atmosphere near the magnetic field Polarity Inversion Line, Astrophys. J., 840, Article 84 (2017). doi: 10.3847/1538-4357/aa6dfdGoogle Scholar

Sheeley, N. R., Walters, J. H., Wang, Y.-M. & Howard, R. A. Continuous tracking of coronal outflows: Two kinds of coronal mass ejections, J. Geophys. Res., 104(A11), 24739–68 (1999). doi: 10.1029/1999JA900308Google Scholar

Sheeley, N. R. Jr & Wang, Y.-M. The recent rejuvenation of the Sun’s large-scale magnetic field: A clue for understanding past and future sunspot cycles, Astrophys. J., 809(2), Article 113 (2015). doi: 10.1088/0004-637X/809/2/113Google Scholar

Simoniello, R., Tripathy, S. C., Jain, K. & Hill, F. A new challenge to solar dynamo models from helioseismic observations: The latitudinal dependence of the progression of the solar cycle, Astrophys. J., 828, Article 41 (2016). doi: 10.3847/0004-637X/828/1/41Google Scholar

Smith, E. J. The heliospheric current sheet, J. Geophys. Res., 106, 15819–31 (2001). doi: 10.1029/2000JA000120Google Scholar

Smith, E. J. & Balogh, A. Ulysses observations of the radial magnetic field, Geophys. Res. Lett., 22, 3317–20 (1995). doi: 10.1029/95GL02826Google Scholar

Solanki, S. K. Sunspots: An overview, Astron. Astrophys. Rev., 11(2–3), 153–286 (2003). doi: 10.1007/s00159-003-0018-4Google Scholar

Solanki, S. K., Krivova, N. A. & Haigh, J. D. Solar irradiance variability and climate, Annu. Rev. Astron. Astrophys., 51, 311–51 (2013). doi: 10.1146/annurev-astro-082812-141007Google Scholar

Stakhiv, M., Landi, E., Lepri, S. T., Oran, R. & Zurbuchen, T. H. On the origin of mid-latitude fast wind: Challenging the two-state solar wind paradigm, Astrophys. J., 801, Article 100 (2015). doi: 10.1088/0004-637X/801/2/100Google Scholar

Stejko, A. M., Guerrero, G. G. & Kosovichev, A. G. 3D global modelling of the solar dynamo, eprint arXiv:1701.08450 (2017).Google Scholar

Strassmeier, K. G. Starspots, Astron. Astrophys. Rev., 17, 251–308 (2009). doi: 10.1007/s00159-009-0020-6Google Scholar

Sun, X., Hoeksema, J. T., Liu, Y. & Zhao, J. On polar magnetic field reversal and surface flux transport during Solar Cycle 24, Astrophys. J., 798, Article 114 (2015). doi: 10.1088/0004-637X/798/2/114Google Scholar

Svalgaard, L., Cliver, E. W. & Kamide, Y. Sunspot cycle 24: Smallest cycle in 100 years? Geophys. Res. Lett., 32, Article L01104 (2004). doi: 10.1029/2004GL021664Google Scholar

Tapping, K. F. The 10.7 cm solar radio flux (F_10.7), Space Weather, 11, 394–406 (2013). doi: 10.1002/swe.20064Google Scholar

Tapping, K. F. & Morgan, C. Changing relationships between sunspot number, total sunspot area and F10.7 in Cycles 23 and 24, Sol. Phys., 292, Article 73 (2017). doi: 10.1007/s11207-017-1111-6Google Scholar

Temmer, M., Rybák, J., Bendík, P., Veronig, A., Vogler, F., Otruba, W., Pötzi, W. & Hanslmeier, A. 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, 735–43 (2006). doi: 10.1051/0004-6361:20054060Google Scholar

Temmer, M., Thalmann, J. K., Dissauer, K., Veronig, A. M., Tschernitz, J., Hinterreiter, J. & Rodriguez, L. On flare-CME characteristics from Sun to Earth combining remote-sensing image data with in situ measurements supported by modelling, Sol. Phys., 292, Article 93 (2017a). doi: 10.1007/s11207-017-1112-5Google Scholar

Temmer, M., Reiss, M. A., Nikolic, L., Hofmeister, S. J. & Veronig, A. M. Preconditioning of interplanetary space due to transient CME disturbances, Astrophys. J., 835, Article 141 (2017b). doi: 10.3847/1538-4357/835/2/141Google Scholar

Török, T., Downs, C., Linker, J. A., Lionello, R., Titov, V. S., Mikić, Z., Riley, P., Caplan, R. M. & Wijaya, J. Sun-to-earth MHD simulation of the 2000 July 14 ‘Bastille Day’ eruption, Astrophys. J., 856, Article 75 (2018). doi: 10.3847/1538-4357/aab36dGoogle Scholar

Usoskin, I. G. A history of solar activity over millennia, Living Rev. Sol. Phys., 14, Article 3 (2017). doi: 10.1007/s41116-017-0006-9Google Scholar

van Driel-Gesztelyi, L. & Green, L. M. Evolution of active regions, Living Rev. Sol. Phys., 12, Article 1 (2015). doi: 10.1007/lrsp-2015-1Google Scholar

Wang, Y. M. The Sun’s large-scale magnetic field and its long-term evolution, Sol. Phys., 224, 21–35 (2004). doi: 10.1007/s11207-005-4982-xGoogle Scholar

Wang, Y.-M. Coronal holes and open magnetic flux, Space Sci. Rev., 144, 383–99 (2009). doi: 10.1007/s11214-008-9434-0Google Scholar

Wang, Y.-M. Solar cycle variation of the Sun’s low-order magnetic multipoles: Heliospheric consequences, Space Sci. Rev., 186, 387–407 (2014). doi: 10.1007/s11214-014-0051-9Google Scholar

Wang, Y.-M. & Colaninno, R. Is Solar Cycle 24 producing more coronal mass ejections than Cycle 23? Astrophys. J. Lett., 784, Article L27 (2014). doi: 10.1088/2041-8205/784/2/L27Google Scholar

Wang, Y.-M. & Muglach, K. On the formation of filament channels, Astrophys. J., 666, 1284–95 (2007). doi: 10.1086/520623Google Scholar

Wang, Y.-M. & Sheeley, N. R. Jr. Solar wind speed and coronal flux-tube expansion, Astrophys. J., 355, 726–32 (1990). doi: 10.1086/168805CrossRef Google Scholar

Wang, Y.-M. & Sheeley, N. R. Jr. Magnetic flux transport and the sun’s dipole moment – New twists to the Babcock-Leighton model, Astrophys. J., 375, 761–70 (1991). doi: 10.1086/170240Google Scholar

Wang, Y.-M. & Sheeley, N. R. Jr. On potential field models of the solar corona, Astrophys. J., 392, 310–19 (1992). doi: 10.1086/171430Google Scholar

Wang, Y.-M. & Sheeley, N. R. Jr., Global evolution of interplanetary sector structure, coronal holes, and solar wind streams during 1976–1993: Stackplot displays based on solar magnetic observations, J. Geophys. Res., 99(A4), 6597–608 (1994). doi: 10.1029/93JA02105Google Scholar

Wang, Y.-M., Sheeley, N. R. Jr & Lean, J. Understanding the evolution of the Sun’s open magnetic flux, Geophys. Res. Lett., 27, 505–8 (2000). doi: 10.1029/1999GL010744Google Scholar

Wang, Y.-M., Sheeley, N. R. Jr & Andrews, M. D. Polarity reversal of the solar magnetic field during cycle 23, J. Geophys. Res., 107(A12), Article 1465 (2002). doi: 10.1029/2002JA009463Google Scholar

Wang, Y. M. & Sheeley, N. R. Jr. Sources of the solar wind at Ulysses during 1990–2006, Astrophys. J., 653, 708–18 (2006). doi: 10.1086/508929Google Scholar

Wang, Y.-M. & Sheeley, N. R. Jr. Understanding the geomagnetic precursor of the solar cycle, Astrophys. J., 694, L11–15 (2009). doi: 10.1088/0004-637X/694/1/L11Google Scholar

Wang, Y.-M., Robrecht, E. & Sheeley, N. R. Jr. On the weakening of the polar magnetic fields during solar cycle 23, Astrophys. J., 707, 1372–86 (2009). doi: 10.1088/0004-637X/707/2/1372Google Scholar

Weiss, N. O. & Tobias, S. M. Physical causes of solar activity, Space Sci. Rev., 94, 99–112 (2000). doi: 10.1023/A:1026790416627Google Scholar

Weiss, N. O. & Thompson, M. J. The solar dynamo, Space Sci. Rev., 144, 53–66 (2009).Google Scholar

Wiegelmann, T., Petrie, G. J. D. & Riley, P. Coronal magnetic field models, Space Sci. Rev., 210, 249–74 (2017). doi: 10.1007/s11214-015-0178-3Google Scholar

Wimmer-Schweingruber, R. F. & Hassler, D. M. Tracing heliospheric structures to their solar origin, AIP Conf. Proc., 1720, Article 100002 (2016). doi: 10.1063/1.4943857Google Scholar

Wimmer-Schweingruber, R. F., von Steiger, R. & Paerli, R. Solar wind stream interfaces in corotating interaction regions: New SWICS/Ulysses results, J. Geophys. Res., 104, 9933–46 (1999). doi: 10.1029/1999JA900038Google Scholar

Wood, B. E., Wu, C. C., Lepping, R. P., Nieves-Chinchilla, T., Howard, R. A., Linton, M. G. & Socker, D. G. A STEREO survey of magnetic cloud coronal mass ejections observed at Earth in 2008–2012, Astrophys. J. Suppl. Ser., 229(2), Article 29 (2017). doi: 10.3847/1538-4365/229/2/29Google Scholar

Wyper, P. E., Antiochos, S. & DeVore, C. R. A universal model for solar eruptions, Nature, 544, 452–9 (2017). doi: 10.1038/nature22050Google Scholar

Xie, H., Mäkelä, P., St. Cyr, O. C. & Gopalswamy, N. Comparison of the coronal mass ejection shock acceleration of three widespread SEP events during solar cycle 24, J. Geophys. Res., 122, 7021–41 (2017). doi: 10.1002/2017JA024218Google Scholar

Yeo, K. L., Krivova, N. A. & Solanki, S. K. Solar cycle variation in solar irradiance, Space Sci. Rev., 186, 137–67 (2014). doi: 10.1007/s11214-014-0061-7Google Scholar

Yeo, K. L., Krivova, N. A. & Solanki, S. K. EMPIRE: A robust empirical reconstruction of solar irradiance variability, J. Geophys. Res., 122, 3888–3914 (2017a). doi: 10.1002/2016JA023733Google Scholar

Yeo, K. L., Solanki, S. K., Norris, C. M., Beeck, B., Unruh, Y. C. & Krivova, N. A. Solar irradiance variability is caused by the magnetic activity on the solar surface, Phys. Rev. Lett., 119(9), Article 091102 (2017b). doi: 10.1103/PhysRevLett.119.091102Google Scholar

Yurchyshyn, V., Yashiro, S., Abramenko, V., Wang, H. & Gopalswamy, N. Statistical distributions of speeds of coronal mass ejections, Astrophys. J., 619, 599–603 (2005). doi: 10.1086/426129Google Scholar

Zacharias, P. An independent review of existing total solar irradiance records, Surv. Geophys., 35, 897–912 (2014). doi: 10.1007/s10712-014-9294-yGoogle Scholar

Zerbo, J.-L. & Richardson, J. D. The solar wind during current and past solar minima and maxima, J. Geophys. Res., 120, 10250–56 (2015). doi: 10.1002/2015JA021407.Google Scholar

Zhang, J., Woch, J., Solanki, S. K., von Steiger, R. & Forsyth, R. Interplanetary and solar surface properties of coronal holes observed during solar maximum, J. Geophys. Res., 108, Article 1144 (2003). doi: 10.1029/2002JA009538Google Scholar

Zhao, L., Landi, E., Lepri, S. T., Kocher, M., Zurbuchen, T. H., Fisk, L. A. & Raines, J. M. An anomalous composition in slow solar wind as a signature of magnetic reconnection in its source region, Astrophys. J. Suppl. Ser., 228(1), Article 4 (2017). doi: 10.3847/1538-4365/228/1/4Google Scholar

Zheng, Y., Macneice, P., Odstrcil, D., Mays, M. L., Rastaetter, L., Pulkkinen, A., Taktakishvili, A., Hesse, M., Kuznetsova, M., Lee, H. & Chulaki, A. Forecasting propagation and evolution of CMEs in an operational setting: What has been learned, Space Weather, 11, 557–74 (2013). doi: 10.1002/swe.20096Google Scholar

Accessibility standard: Unknown

Why this information is here

This section outlines the accessibility features of this content - including support for screen readers, full keyboard navigation and high-contrast display options. This may not be relevant for you.

Accessibility Information

Accessibility compliance for the HTML of this chapter is currently unknown and may be updated in the future.