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Probing the Magnetic Causes of CMEs: Free Magnetic Energy More Important Than Either Size Or TwistTo probe the magnetic causes of CMEs, we have examined three types of magnetic measures: size, twist and total nonpotentiality (or total free magnetic energy) of an active region. Total nonpotentiality is roughly the product of size times twist. For predominately bipolar active regions, we have found that total nonpotentiality measures have the strongest correlation with future CME productivity (approx. 75% prediction success rate), while size and twist measures each have a weaker correlation with future CME productivity (approx. 65% prediction success rate) (Falconer, Moore, & Gary, ApJ, 644, 2006). For multipolar active regions, we find that the CME-prediction success rates for total nonpotentiality and size are about the same as for bipolar active regions. We also find that the size measure correlation with CME productivity is nearly all due to the contribution of size to total nonpotentiality. We have a total nonpotentiality measure that can be obtained from a line-of-sight magnetogram of the active region and that is as strongly correlated with CME productivity as are any of our total-nonpotentiality measures from deprojected vector magnetograms. We plan to further expand our sample by using MDI magnetograms of each active region in our sample to determine its total nonpotentiality and size on each day that the active region was within 30 deg. of disk center. The resulting increase in sample size will improve our statistics and allow us to investigate whether the nonpotentiality threshold for CME production is nearly the same or significantly different for multipolar regions than for bipolar regions. In addition, we will investigate the time rates of change of size and total nonpotentiality as additional causes of CME productivity.
Document ID
20070013789
Acquisition Source
Marshall Space Flight Center
Document Type
Conference Paper
Authors
Falconer, D. A.
(NASA Marshall Space Flight Center Huntsville, AL, United States)
Moore, R. L.
(NASA Marshall Space Flight Center Huntsville, AL, United States)
Gary, G. A.
(NASA Marshall Space Flight Center Huntsville, AL, United States)
Date Acquired
August 23, 2013
Publication Date
December 16, 2006
Subject Category
Solar Physics
Meeting Information
Meeting: 2006 Fall American Geophysical Union Meeting
Location: San Francisco, CA
Country: United States
Start Date: December 11, 2006
End Date: December 16, 2006
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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