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The nature of the sunspot phenomenon. III - Energy consumption and energy transport. IV - The intrinsic instability of the magnetic configurationThe basic relation is described between conversion of thermal energy into convective fluid motion and convective transport of thermal energy, and the equilibrium configuration of a sunspot's magnetic field is shown to be unstable to the hydromagnetic exchange instability. It is determined that heat transport necessarily accompanies convective driving of fluid motion and that the formation of cool sunspots requires convection extending coherently over several scale heights, a distance of at least 500 km. Several theoretical possibilities for sunspot stabilization are reviewed, and it is suggested that a suitable redistribution of cooling in the umbra may be the stabilization mechanism. It is believed that if cooling extends to a great depth in an elongated portion of a sunspot, the magnetic pressure on the boundary will be reduced, tending to reduce the elongation.
Document ID
19750045065
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Parker, E. N.
(Chicago, University Chicago, Ill., United States)
Date Acquired
August 8, 2013
Publication Date
February 1, 1975
Publication Information
Publication: Solar Physics
Volume: 40
Subject Category
Solar Physics
Accession Number
75A29137
Funding Number(s)
CONTRACT_GRANT: NGL-14-001-001
Distribution Limits
Public
Copyright
Other

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