CMEs from emptied filament channels
Abstract
Using SDO, SOHO and STEREO data we analyze several CMEs originating from emptied filament channels. The CMEs occurred 2 to 4 days after the original filament plasma appeared to drain away leaving the channels empty. Observed on the limb, these CMEs appeared to be very faint and without one of the three well known components - the bright core. For one case, the CME of May 23, 2010, we traced changes in the photospheric magnetic flux inside and neighboring the filament channel from before to after the filament plasma had drained. We found that the emptying process was associated with relatively fast changes in the magnetic flux. The magnetic flux changes were due to localized photospheric cancellation, which we believe caused an increase in the magnetic flux trapped in the filament cavity, by the same process that creates filament channels in the first place. Using a PFSS model, we also traced changes in the magnetic field configuration overlying the filament channel from May 20 through May 25, 2010. We found that the connectivity of coronal loops overlying the arcade changed as a result of the emergence of a new active region, which resulted in a reduction of flux density in the overlying arcade and the subsequent complete eruption of the coronal arcade system with the filament cavity it encompassed. We interpret this sequence of events in terms of a continuous removal, via reconnection with the fields of the newly emerging active region, of the field lines in the arcade overlying the filament channel, which together with the increase of the fields inside the cavity rapidly lead to the complete destabilization of the configuration and the birth of the CME. We view this case as a classic example of the tether-cutting model of CME initiation.
- Publication:
-
Solar Heliospheric and INterplanetary Environment (SHINE 2011)
- Pub Date:
- July 2011
- Bibcode:
- 2011shin.confE..31P