000004543 001__ 4543
000004543 005__ 20200114142207.0
000004543 037__ $$aPOSTER-2020-0008
000004543 100__ $$aImmanuel Christopher Jebaraj, Immanuel Christopher
000004543 245__ $$aOrigin of the two shock waves associated with the September 27/28, 2012 event
000004543 260__ $$c2019
000004543 269__ $$c2019-04-07
000004543 520__ $$aCoronal  mass  ejections  and  flares  are  solar  eruptive  phenomena  responsible  for  space  weather  activities  nearEarth. They can accelerate particles, and generate shock waves which are a threat to our technologies at Earth andin space. Therefore, predicting shock arrival at Earth has been an important goal for space weather. Space basedradio observations provide the unique opportunity to track shock waves in the inner heliosphere.We present the study of CME/flare event on September 27/28, 2012. The GOES C3.1 flare that originated fromNOAA AR 1577 was associated with a full-halo CME (first seen in SOHO/LASCO C2 field of view at 23:47)and white light shock wave observed by all three spacecraft STEREO A, STEREO B, and SOHO. The associatedradio event shows a group of type III bursts and two somewhat unusual type II bursts with significantly differentstarting  frequencies.  To  understand  the  origin  of  the  two  shock  waves  we  performed  multi-wavelength  study,and perform radio triangulation to get their source position in the 3D space. For the radio triangulation study,we  used  goniopolarimetric  measurements  from  STEREO/WAVES  and  WIND/WAVES  instruments.  We  alsodid  data-driven  modelling  of  the  CME  propagation  using  EUHFORIA  cone  model  (EUropean  HeliosphericFORecasting Information Asset) and validate the results by comparison with in-situ data.Results  of  this  study  indicate  that,  although  temporal  association  between  the  shock  and  the  CME  is  good,the  low  frequency  type  II  burst  occurs  significantly  higher  in  the  solar  corona  than  the  associated  CME  andhas therefore unclear origin. To understand the origin of the low frequency type II burst we studied precedingevent  at  10:20  UT  (STEREO  A/COR2)  on  September  27,  2012.  The  radio  triangulation  study  shows  that  thetype  II  source  positions  are  in  the  southern  solar  hemisphere  and  thus  may  be  associated  to  the  type  II  emis-sions in the radio event succeeding it. We therefore discuss different possibilities for the origin of two type II bursts.
000004543 594__ $$aNO
000004543 700__ $$aMagdalenic, Jasmina
000004543 700__ $$aScolini, Camilla
000004543 700__ $$aRodriguez, Luciano
000004543 700__ $$aPoedts, Stefaan
000004543 700__ $$aKilpua, Emilia
000004543 700__ $$aKrupar, Vratislav
000004543 700__ $$aPomoell, Jens
000004543 700__ $$aTemmer, Manuela (7)
000004543 773__ $$tEGU 2019, Vienna
000004543 8560_ $$fimmanuel.jebaraj@observatoire.be
000004543 980__ $$aCPOSTER