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Leamon et al. 2004
Leamon, R.J., Canfield, R.C., Jones, S.L., Lambkin, K., Lundberg, B.J. and Pevtsov, A.A. (2004). Helicity of magnetic clouds and their associated active regions. Journal of Geophysical Research 109. doi: 10.1029/2003JA010324. issn: 0148-0227.

In this work we relate the magnetic and topological parameters of twelve interplanetary magnetic clouds to associated solar active regions. We use a cylindrically symmetric constant-α force-free model to derive field line twist, total current, and total magnetic flux from in situ observations of magnetic clouds. We compare these properties with those of the associated solar active regions, which we infer from solar vector magnetograms. Our comparison of fluxes and currents reveals: (1) the total flux ratios ΦMCAR tend to be of order unity, (2) the total current ratios IMC/IAR are orders of magnitude smaller, and (3) there is a statistically significant proportionality between them. Our key findings in comparing total twists αL are that (1) the values of (αL)MC are typically an order of magnitude greater than those of (αL)AR and (2) there is no statistically significant sign or amplitude relationship between them. These findings compel us to believe that magnetic clouds associated with active region eruptions are formed by magnetic reconnection between these regions and their larger-scale surroundings, rather than simple eruption of preexisting structures in the corona or chromosphere.

BACKGROUND DATA FILES

Abstract

Keywords
Interplanetary Physics, Interplanetary magnetic fields, Solar Physics, Astrophysics, and Astronomy, Corona, Solar Physics, Astrophysics, and Astronomy, Magnetic fields, Solar Physics, Astrophysics, and Astronomy, Coronal mass ejections, magnetic clouds, active regions, electric currents, solar eruptions, magnetic helicity
Journal
Journal of Geophysical Research
http://www.agu.org/journals/jb/
Publisher
American Geophysical Union
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