Please use this identifier to cite or link to this item: http://hdl.handle.net/2248/2686
Title: Dynamics of the Solar Magnetic Network. II. Heating the Magnetized Chromosphere
Authors: Hasan, S. S
van Ballegooijen, A. A
Keywords: MHD—Sun;chromosphere—Sun;magnetic fields—Sun;oscillations
Issue Date: 20-Jun-2008
Publisher: The American Astronomical Society
Citation: The Astrophysical Journal, Vol. 680, No. 2, pp. 1542 – 1552
Abstract: We consider recent observations of the chromospheric network and argue that the bright network grains observed in the Ca ii H and K lines are heated by an as-yet-unidentified quasi-steady process. We propose that the heating is caused by dissipation of short-period magnetoacoustic waves in magnetic flux tubes (periods less than 100 s). Magnetohydrodynamic (MHD) models of such waves are presented. We consider wave generation in the network due to two separate processes: (1) transverse motions at the base of the flux tube and (2) the absorption of acoustic waves generated in the ambient medium. We find that the former mechanism leads to efficient heating of the chromosphere by slow magnetoacoustic waves propagating along magnetic field lines. This heating is produced by shock waves with a horizontal size of a few hundred kilometers. In contrast, acoustic waves excited in the ambient medium are converted into transverse fast modes that travel rapidly through the flux tube and do not form shocks, unless the acoustic sources are located within 100 km from the tube axis. We conclude that the magnetic network may be heated by magnetoacoustic waves that are generated in or near the flux tubes.
URI: http://hdl.handle.net/2248/2686
ISSN: 0004-637X
???metadata.dc.relation.uri???: http://arxiv.org/abs/0802.3509
http://www.journals.uchicago.edu/doi/abs/10.1086/587773
Appears in Collections:IIAP Publications

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