The emergence of weakly twisted magnetic fields in the sun

Journal Article · Wed Nov 20 04:00:00 EST 2013 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/778/1/42· OSTI ID:22342006

Archontis, V. ^[1]; Hood, A. W. ^[2]; Tsinganos, K. ^[3]

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1. Section of Astrophysics, Astronomy and Mechanics, Department of Physics, University of Athens, Panepistimiopolis 15784, Athens (Greece)
2. School of Mathematics and Statistics, St. Andrews University, St. Andrews KY169SS (United Kingdom)
3. National Observatory of Athens, Lofos Nymphon, Thissio 11810, Athens (Greece)

We have studied the emergence of a weakly twisted magnetic flux tube from the upper convection zone into the solar atmosphere. It is found that the rising magnetized plasma does not undergo the classical, single Ω-shaped loop emergence, but it becomes unstable in two places, forming two magnetic lobes that are anchored in small-scale bipolar structures at the photosphere, between the two main flux concentrations. The two magnetic lobes rise and expand into the corona, forming an overall undulating magnetic flux system. The dynamical interaction of the lobes results in the triggering of high-speed and hot jets and the formation of successive cool and hot loops that coexist in the emerging flux region. Although the initial emerging field is weakly twisted, a highly twisted magnetic flux rope is formed at the low atmosphere, due to shearing and reconnection. The new flux rope (hereafter post-emergence flux rope) does not erupt. It remains confined by the overlying field. Although there is no ejective eruption of the post-emergence rope, it is found that a considerable amount of axial and azimuthal flux is transferred into the solar atmosphere during the emergence of the magnetic field.

• OSTI ID: 22342006
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 778; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ABUNDANCE
CONCENTRATION RATIO
CONVECTION
ECOLOGICAL CONCENTRATION
ERUPTION
INTERACTIONS
MAGNETIC FIELDS
MAGNETIC FLUX
PHOTOSPHERE
PLASMA
RISE
SUN
VELOCITY