Hostname: page-component-cd9895bd7-lnqnp Total loading time: 0 Render date: 2024-12-26T04:12:38.488Z Has data issue: false hasContentIssue false

Theoretical Interpretation of Magnetic Activity

Published online by Cambridge University Press:  12 April 2016

Eugene N. Parker*
Affiliation:
Enrico Fermi Instituteand Departments of Physics and Astronomy, University of Chicago, Chicago, Illinois 60637, USA

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Magnetic fields generated and driven by thermal convection are the primary cause of solar activity. There are many facets of the activity, such as plages, flares, sunspots, coronal heating, and the variation of solar luminosity or irradiance whose nature and cause are understood only partially or not at all, although detailed superficial observational descriptions are available. It is suggested that the inferred 105 gauss azimuthal field bundles may be a direct result of the emergence of Ω-loops to form bipolar magnetic regions on the surface in association with an increase in solar irradiance.

Type
Solar and Stellar Oscillations, Irradiance Variations, and their Interpretation
Copyright
Copyright © Kluwer 1994

References

Dennis, B.R. 1985 Solar hard X-ray bursts. Solar Phys. 100, 465490.Google Scholar
D’silva, S. & Choudhuri, A.R. 1993 A theoretical model for tilts of bipolar magnetic regions. Astron. Astrophys. 272, 621633.Google Scholar
Eddy, J.A. 1976 The Maunder Minimum. Science 192, 11891202.CrossRefGoogle ScholarPubMed
Eddy, J.A. 1977 Historical evidence for the existence of the solar cycle. In Solar Output and its Variation (ed. White, O.R.), pp. 5177. Colorado Association University Press.Google Scholar
Fan, Y., Fisher, G.H. & Deluca, E.E. 1993 The origin of morphological asymmetries in bipolar active regions. Astrophys. J. 405, 390401.Google Scholar
Fan, Y., Fisher, G.H. & McClymont, A.N. 1994 Astrophys. J., submitted.Google Scholar
Fisher, G.H., McClymont, A.N. & Chou, D.Y. 1991 The strerching of magnetic flux tubes in the convective overshoot region. Astrophys. J. 374, 766772.Google Scholar
Foukal, P. & Lean, J. 1986 The influence of faculae on total solar irradiance and luminosity. Astrophys. J. 302, 826835.CrossRefGoogle Scholar
Frus-Christenson, E. & Lassen, K. 1991 Length of the solar cycle: An indicator of solar activity closely associated with climate. Science 254, 698700.CrossRefGoogle Scholar
Gaizauskas, V., Harvey, K.L., Harvey, J.W. & Zwaan, C. 1983 Large-scale patterns formed by solar active regions during the ascending phase of cycle 21, Astrophys. J 265, 10561065.Google Scholar
Hoyt, D.V., Kyle, H.L., Hickey, J.R. & Maschnoff, R.H. 1992 The Nimbus 7 total irradiance: A new algorithm for its deviation. J. Geophys. Res. 97, 5163.Google Scholar
Moreno-Insertis, F., Schüssler, M., & Feriz-Mas, A. 1984 Private communication.Google Scholar
Moreno-Insertis, F., Schüssler, M. & Feriz-Mas, A. 1993 Astron. Astrophys., submitted.Google Scholar
Parker, E.N. 1955 The formation of sunspots from the solar toroidal field. Astrophys. J. 121, 491507.Google Scholar
Parker, E.N. 1984 Stellar fibril systems: I. Reduced energy state. Astrophys. J. 283, 343348.Google Scholar
Parker, E.N. 1993 A solar dynamo surface wave at the interface between convection and nonuniform rotation. Astrophys. J. 408, 707719.Google Scholar
Radick, R.R., Lockwood, G.W. & Baliunas, S.L. 1990 Solar activity and brightness variations: A glimpse at the Sun’s history. Science 24, 3944.Google Scholar
Solanki, S.K. 1993 Small-scale solar magnetic fields: An overview. Space Sci. Rev. 63, 1186.CrossRefGoogle Scholar
Spruit, H.C. 1974 A model of the solar convective zone. Solar Phys. 34, 277290.CrossRefGoogle Scholar
Spruit, H.C. & Van Ballegoouen, A.A. 1982 Stability of toroidal flux tubes in stars. Astron. Astrophys. 113, 350.Google Scholar
Wigley, T.M.L. & Kelly, P.M. 1990 Holocene climatic change, 14C wiggles and variations in solar irradiance. Phil. Trans. Roy. Soc. London A330, pp. 547560.Google Scholar
Zhang, Q., Soon, W.H., Baliunas, S.L., Lockwood, G.W., Skiff, B.A. & Radick, R.R. 1993 Possible method for determining brightness variations of the Sun in past centuries from solar type stars Astrophys. J. Letters, submitted.Google Scholar
Zwaan, C. 1985 The emergence of magnetic flux. Solar Phys. 100, 397414.Google Scholar