Analysis of the surge of 09-May-2012

MANDRINI, C.H.; LUONI, M.L.; LÓPEZ FUENTES, M.C.; DÉMOULIN, P.; POISSON, M.; CRISTIANI, G.D.

Simposio; IAU Symposium 327, Fine structure and dynamics of the solar atmosphere; 2016

We study a chromospheric mass ejection or surge observed on 09-May-2012 in active region (AR)NOAA 11476. The event is associated with an M4.7 flare that starts at approximately 12:23 UT. Forthe analysis we use observations in multiple wavelenghts (EUV, X rays, H-alpha and magnetograms)from di↵erent instruments (SDO/AIA, SDO/HMI, Hinode/SXT, RHESSI and HASTA). The study ofthe magnetic configuration indicates the presence of a fastly rotating bipolar structure at the center ofthe AR. This evolution along some tens of hours before the event transfers a high amount of twist tothe magnetic structure in the coronal volume above the bipole. The observations suggest that the freemagnetic energy accumulated in this way is released through reconnection due to the interaction of thebipole with the preexisting coronal structure. As a consequence of this, a flare occurs and chromosphericmaterial is ejected along the reconnected loops in the form of a surge. Computing the magnetic topologyon the basis of a force-free model of the coronal field, we identify the location of the quasi-separatix layers(QSLs) where reconnection is prone to occur and obtain a detailed description of the connectivity of theloops involved in the process.