Flares, coronal mass ejections, and magnetic clouds from a mixed helicity active region

MANDRINI, C. H.; CHANDRA, R.; PARIAT, E.; SCHMIEDER, B.; DÉMOULIN, P.; TOROK, T.; UDDIN, W.

Berlín

Simposio; SCOSTEP Symposium 2010 - STP12; 2010

Scientific Committee on Solar-Terrestrial Physics

On 18 and 20 November 2003, active region (AR) 10501 produced a series of M flares all of them associated with coronal mass ejections (CMEs), some of which were identified as the source of subsequent magnetic clouds at 1 AU. The particularity of this AR is that while observational tracers of the magnetic helicity sign indicate that the large scale field in the region had negative magnetic helicity, the MC associated to the most intense flare/CME on November 18 showed the opposite sign. Furthermore, the filaments observed on November 20 present morphological characteristics that correspond to a negative magnetic helicity sign, the rotation of the polarities of an emerging bipole indicate negative magnetic helicity sign injection; however, the flare ribbons observed after two homologous events can be connected either by field lines computed using a positive or a negative helicity sign magnetic field. We combine Halpha, EUV, hard X-rays, and magetic field data analysis with magnetic field modeling, topology, and magnetic helicity injection computations to understand the origin of the helicity sign discrepancies and the initiation scenario of the ejective events.