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Quiet sun magnetic fields vs. polar faculae – local vs. global dynamo?
Author(s) -
Okunev O. V.,
Domínguez Cerdeña I.,
Puschmann K. G.,
Kneer F.,
Sánchez Almeida J.
Publication year - 2005
Publication title -
astronomische nachrichten
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.394
H-Index - 63
eISSN - 1521-3994
pISSN - 0004-6337
DOI - 10.1002/asna.200410377
Subject(s) - physics , dynamo , polar , astrophysics , magnetic field , gauss , quiet , solar wind , magnetic flux , solar dynamo , flux (metallurgy) , astronomy , geophysics , dynamo theory , materials science , quantum mechanics , metallurgy
Quiet Sun magnetic fields in the internetwork are almost ubiquitous. Simultaneous observations in infra‐red and visible lines and high spatial resolution ( < 0.5″) data in visible lines show that their field strengths range from below few hundred Gauss to kilo‐Gauss. Most of the flux is contained in small‐scale, strong‐field features located mainly in intergranular lanes. The average unsigned flux density exceeds 20 Gauss. The new detections are confirmed by recent quiet Sun observations in the G band. The generation of the strong fields in the internetwork, which may be due to a local dynamo, poses a challenging problem. – Polar faculae (PFe) are small‐scale magnetic features at the polar caps of the Sun. They take part in the solar cycle and are thus likely to be rooted deeply in the solar interior. They are the result of the global dynamo at the solar poles. PFe also possess kilo‐Gauss magnetic fields which have the same polarity as the global magnetic field. The rôle of quiet Sun magnetic field structures and of PFe for the dynamics of the corona and for the solar wind are addressed. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)