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Photospheric Magnetic Evolution in the WHI Active RegionsSequences of line-of-sight (LOS) magnetograms recorded by the Michelson Doppler Imager are used to quantitatively characterize photospheric magnetic structure and evolution in three active regions that rotated across the Sun s disk during the Whole Heliosphere Interval (WHI), in an attempt to relate the photospheric magnetic properties of these active regions to flares and coronal mass ejections (CMEs). Several approaches are used in our analysis, on scales ranging from whole active regions, to magnetic features, to supergranular scales, and, finally, to individual pixels. We calculated several parameterizations of magnetic structure and evolution that have previously been associated with flare and CME activity, including total unsigned magnetic flux, magnetic flux near polarity-inversion lines, amount of canceled flux, the "proxy Poynting flux," and helicity flux. To catalog flare events, we used flare lists derived from both GOES and RHESSI observations. By most such measures, AR 10988 should have been the most flare- and CME-productive active region, and AR 10989 the least. Observations, however, were not consistent with this expectation: ARs 10988 and 10989 produced similar numbers of flares, and AR 10989 also produced a few CMEs. These results highlight present limitations of statistics-based flare and CME forecasting tools that rely upon line-of-sight photospheric magnetic data alone.
Document ID
20120012553
Acquisition Source
Goddard Space Flight Center
Document Type
Reprint (Version printed in journal)
Authors
Welsch, B. T.
(California Univ. Berkeley, CA, United States)
McTiernan, J. M.
(California Univ. Berkeley, CA, United States)
Christe, S.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Date Acquired
August 26, 2013
Publication Date
May 11, 2012
Publication Information
Publication: Solar Physics
Publisher: Springer-Verlag G.m.b.H. and Co. K.G.
Volume: 274
Issue: 2-Jan
Subject Category
Solar Physics
Report/Patent Number
GSFC.JA.01211.2012
Funding Number(s)
CONTRACT_GRANT: NNX08AI56G
CONTRACT_GRANT: NNX08AJ18G
CONTRACT_GRANT: NSF AGS-1024862
CONTRACT_GRANT: NSF ATM-0752597
CONTRACT_GRANT: NAS5-98033
Distribution Limits
Public
Copyright
Other

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