Jebaraj, Immanuel Christopher

Seminar presented at Royal Observatory of Belgium on 2018-09-13

Abstract: During solar eruptive events such as Flares and CMEs (Coronal Mass Ejections) plasma is heated, waves are generated and particles accelerated. CMEs and associated shocks are the main drivers of geomagnetic storms, and therefore the subject of numerous studies. We present a study of the CME/flare event observed on the September 27, 2012. The GOES C3.1 flare and associated CME originated from the NOAA AR 1577, which had a beta-gamma configuration of its photospheric magnetic field in the moment of eruption. The full-Halo CME which drives a white light shock was observed by all three spacecraft STEREO A, STEREO B, and SOHO/LASCO. It was first seen in the SOHO/LASCO C2 field of view at 23:47 UT. The associated radio event consisted of type II (signature of the shock) and type III (signature of fast electron beams propagating along open field lines) radio bursts. In this multi-wavelength study, we determined the physical characteristics of the CME and the CME-driven shock wave, in order to understand their association. To obtain the propagation path of the shock in 3D, we perform radio triangulation using the goniopolarimetric measurements from STEREO/WAVES and WIND/WAVES instruments. We perform data-driven modelling of the CME propagation using EUHFORIA flux rope model (EUropean Heliospheric FORecasting Information Asset) and validate the results by comparing with in-situ data. We demonstrate the need for 3D reconstructions in the studies of coronal shocks and associated CMEs. The preliminary results of this study indicate that, although temporal association between the shock and the CME is good, the type II burst occurs significantly higher in the corona than the associated CME.

Keyword(s): Radio triangulation ; CME ; Shock wave
Funding: 3FULLCOST/3FULLCOST/3FULLCOST