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Flare research with the NASA/MSFC vector magnetograph - Observed characteristics of sheared magnetic fields that produce flaresThe present MSFC Vector Magnetograph has sufficient spatial resolution (2.7 arcsec pixels) and sensitivity to the transverse field (the noise level is about 100 gauss) to map the transverse field in active regions accurately enough to reveal key aspects of the sheared magnetic fields commonly found at flare sites. From the measured shear angle along the polarity inversion line in sites that flared and in other shear sites that didn't flare, evidence is found that a sufficient condition for a flare to occur in 1000 gauss fields in and near sunspots is that both: (1) the maximum shear angle exceed 85 degrees; and (2) the extent of strong shear (shear angle of greater than 80 degrees) exceed 10,000 km.
Document ID
19880050677
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Moore, R. L. (NASA Marshall Space Flight Center Huntsville, AL, United States)
Hagyard, M. J. (NASA Marshall Space Flight Center Huntsville, AL, United States)
Davis, J. M. (NASA Marshall Space Flight Center Huntsville, AL, United States)
Date Acquired
August 13, 2013
Publication Date
January 1, 1987
Publication Information
Publication: Solar Physics
Volume: 113
Issue: 1-2,
ISSN: 0038-0938
Subject Category
SOLAR PHYSICS
Distribution Limits
Public
Copyright
Other