Abstract
Coronal magnetic fields calculated by the methods developed in Paper I (Altschuler and Newkirk, 1969) and the empirical description of the solar corona of November 1966 derived in Paper II (Newkirket al., 1970) are combined in order to investigate what connection exists between the magnetic fields and the density structure of the corona.
To facilitate the comparison of magnetic fields with gross coronal features, magnetic configurations are divided into three classifications - diverging fields (DF), low magnetic arcades (LMA), and high magnetic arcades (HMA). It is found that DF's occur above active plages and correlate primarily with low enhancements in the corona. Magnetic arcades (MA) appear to correlate with coronal streamers, implying that streamers form above the neutral line between extended regions in the photosphere of opposite magnetic polarity.
Comparison of the density structure of the corona - as evidenced by rays, arches, and plumes - with the shape of the calculated magnetic field lines shows very satisfactory agreement. This agreement indicates that the potential magnetic field model is reasonably valid in the lower corona (r < 2.5R) and that the density structure of the lower corona correlates with magnetic tubes containing varying amounts of coronal plasma.
Density enhancements in the lower corona are investigated with the conclusion that the presence of high intensity magnetic fields in the photosphere implies elevated density in the corona. The geometry of the field determines the morphological form taken by the density enhancement.
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The National Center for Atmospheric Research is sponsored by the National Science Foundation.
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Newkirk, G., Altschuler, M.D. Magnetic fields and the solar corona. Sol Phys 13, 131–152 (1970). https://doi.org/10.1007/BF00963948
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DOI: https://doi.org/10.1007/BF00963948