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The Dynamics of Solar Coronal Magnetic Fields
Published online by Cambridge University Press: 19 July 2016
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The solar corona is a hot (106K) highly ionized plasma structured by its magnetic field into open regions where the solar wind escapes and closed regions where relatively dense plasma is trapped in near static equilibrium. Observed in Thomson-scattered light at times of solar eclipse or by artificial occultation using a coronagraph, these closed regions show up conspicuously as helmet-shaped bright structures. The large scale corona evolves in time in response to the solar dynamo that continually injects new magnetic flux into the corona with the eventual reversal of the global magnetic polarity at the end of each half cycle of eleven years. It was discovered in the 1970s using spaceborne coronagraphs that in addition to its long-term evolution, the corona also undergoes dynamical reconfiguration with ejection of mass of the order of 1015g into interplanetary space (MacQueen 1980). These time dependent phenomena take place once every few days at solar activity minimum and as often three times a day at solar activity maximum. Since the 1970s, coronal mass ejections have been studied at the High Altitude Observatory by the use of the coronagraph on the NASA Solar Maximum Mission Satellite and groundbased instruments at Hawaii. This brief review presents three points of interest in the coronal mass ejection as a hydromagnetic process, emphasizing the unique opportunity offered by the corona to study hydromagnetic phenomena by direct observation (Hundhausen 1987, Kahler 1987, Low 1986).
- Type
- 1. A Survey of Magnetic Phenomena near the Solar Photosphere, in the Corona, and in Stellar Winds
- Information
- Copyright
- Copyright © Kluwer 1990
References
Harrison, R. A.
1986, Solar coronal mass ejections and flares,
Astron. Astrophys.
162, 283.Google Scholar
Hu, Y. Q., Zhu, Z. W., Hundhausen, A. J., Holzer, T. E., and Low, B. C.
1989, Slow shocks in an open magnetic field near the sun,
Scientia Sinica
, in press.Google Scholar
Hundhausen, A. J.
1987, The origin and propagation of coronal mass ejections, in
Proc. of Sixth International Solar Wind Conference
, edited by Pizzo, V., Holzer, T. and Sime, D.
(NCAR Publ. TN-306).Google Scholar
Hundhausen, A. J., Holzer, T. E., and Low, B. C.
1987, Do slow shocks precede some coronal mass ejections,
J. Geophys. Res.
92, 11173.Google Scholar
Low, B. C.
1984, Self-similar magnetohydrodynamics IV. The physics of coronal mass ejections,
Ap. J.
281, 392.Google Scholar
Low, B. C.
1986, Coronal mass ejections, in
Highlights of Astronomy
, edited by Swing, J. P. (Reidel).Google Scholar
MacQueen, R. M.
1980, Coronal transients: a summary,
Phil. Trans. R. Soc. (Lon.)
A297, 605.Google Scholar
Sime, D. G.
1989, Coronal mass ejection rates and the evolution of the large scale K-coronal density distribution,
J. Geophys. Res.
94, 151.CrossRefGoogle Scholar
Sime, D. G., and Hundhausen, A. J.
1987, The coronal mass ejections of July 6 1980: A candidate for interpretation as a coronal shock wave,
J. Geophys. Res.
92, 1049.Google Scholar
Steinolfson, R. S., and Hundhausen, A. J.
1989a, Waves in low-beta plasmas: slow shocks,
J. Geophys. Res.
94, 1222.Google Scholar
Steinolfson, R. S., and Hundhausen, A. J.
1989b, MHD intermediate shocks in coronal mass ejections,
J. Geophys. Res.
, in press.CrossRefGoogle Scholar
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