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Two Types of Magnetic Flux Cancellation in the Solar Eruption of 2007 May 20We study a solar eruption of 2007 May 20, in an effort to understand the cause of the eruption's onset. The event produced a GOES class B6.7 flare peaking at 05:56 UT, while ejecting a surge/filament and producing a coronal mass ejection (CME). We examine several data sets, including H-alpha images from the Solar Optical Telescope (SOT) on Hinode, EUV images from TRACE, and line-of-sight magnetograms from SOHO/MDI. Flux cancelation occurs among two different sets of flux elements inside of the erupting active region: First, for several days prior to eruption, opposite-polarity sunspot groups inside the region move toward each other, leading to the cancelation of approximately 10^{21} Mx of flux over three days. Second, within hours prior to the eruption, positive-polarity moving magnetic features (MMFs) flowing out of the positive-flux spots at approximately 1 kilometer per second repeatedly cancel with field inside a patch of negative-polarity flux located north of the sunspots. The filament erupts as a surge whose base is rooted in the location where the MMF cancelation occurs, while during the eruption that filament flows out along the polarity inversion line between the converging spot groups. We conclude that a plausible scenario is that the converging spot fields brought the magnetic region to the brink of instability, and the MMF cancelation pushed the system "over the edge." triggering the eruption.
Document ID
20100036845
Acquisition Source
Marshall Space Flight Center
Document Type
Presentation
Authors
Sterlin, Alphonse C.
(NASA Marshall Space Flight Center Huntsville, AL, United States)
Moore, Ronald L.
(NASA Marshall Space Flight Center Huntsville, AL, United States)
Mason, Helen
(Cambridge Univ. United Kingdom)
Date Acquired
August 25, 2013
Publication Date
July 18, 2010
Subject Category
Solar Physics
Report/Patent Number
M10-0775
M10-0864
Meeting Information
Meeting: 38th Committee on Space Research COSPAR Scientific
Location: Bremen
Country: Germany
Start Date: July 18, 2010
End Date: July 25, 2010
Distribution Limits
Public
Copyright
Public Use Permitted.
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