Magnetic helicity transport in corona and filament eruptions
Magnetic helicity transport in corona and filament eruptions
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DOI：
10.1023/b:sola.0000013035.62270.e4
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发表时间：
2003-12
期刊：
影响因子：
2.8
通讯作者：
P. Romano;L. Contarino;F. Zuccarello
中科院分区：
文献类型：
--
作者：
P. Romano;L. Contarino;F. Zuccarello
利用迈克尔逊多普勒成像仪（MDI）拍摄的28小时时间序列的视线磁图，我们确定了活动区NOAA 8375中暗条足点处的磁通量变化和磁螺旋度传输率。由于两个足点的剪切运动，暗条的特征是螺旋度正变化，并在观测期间显示出几次部分喷发。特别是，我们考虑了太阳地球物理数据的Hα每日报告中记录的4个事件。我们发现了一个很强的时间相关性之间的灯丝爆发和螺旋度运输从光球磁结构在灯丝的脚点到日冕：在至少一个脚点，所有的事件之前有一个明显的增加，其次是一个小的减少新兴的磁通量和磁螺旋度的变化，由于剪切运动。我们比较了这两种机制的螺旋度传输，并发现，主要的作用，驱动暗条不稳定性的出现，新的磁通量从对流区。
Using a 28-hour time series of line-of-sight magnetograms taken by the Michelson Doppler Imager (MDI), we determined the magnetic flux variations and the rate of magnetic helicity transport at the footpoints of a filament in active region NOAA 8375. The filament was characterized by a positive helicity change due to shearing motions in both footpoints and showed several partial eruptions during the observing time. In particular, we considered 4 events registered in the Hα daily reports ofSolar Geophysical Data. We found a strong temporal correlation between filament eruptions and helicity transport from the photospheric magnetic structures at the filament footpoints into the corona: in at least one footpoint, all of the events were preceded by an evident increase and followed by a small decrease of the emerging magnetic flux and of the magnetic helicity change due to shearing motions. We compared these two mechanisms of helicity transport and found that the predominant role to drive filament instability is played by emergence of new magnetic flux from the convection zone.