Dacie, S;
Torok, T;
Demoulin, P;
Linton, MG;
Downs, C;
van Driel-Gesztelyi, L;
Long, DM;
(2018)
Sequential Eruptions Triggered by Flux Emergence: Observations and Modeling.
The Astrophysical Journal
, 862
(2)
, Article 117. 10.3847/1538-4357/aacce3.
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Abstract
We describe and analyze observations by the Solar Dynamics Observatory of the emergence of a small, bipolar active region within an area of unipolar magnetic flux that was surrounded by a circular, quiescent filament. Within only 8 hours from the start of the emergence, a partial splitting of the filament and two consecutive coronal mass ejections took place. We argue that all three dynamic events occurred as a result of particular magnetic-reconnection episodes between the emerging bipole and the pre-existing coronal magnetic field. To substantiate our interpretation, we consider 3D magnetohydrodynamic simulations that model the emergence of magnetic flux in the vicinity of a large-scale coronal flux rope. The simulations qualitatively reproduce most of the reconnection episodes suggested by the observations, as well as the filament splitting, the first eruption, and the formation of sheared/twisted fields that may have played a role in the second eruption. Our results suggest that the position of emerging flux with respect to the background magnetic configuration is a crucial factor for the resulting evolution, while previous results suggest that parameters such as the orientation or the amount of emerging flux are important as well. This poses a challenge for predicting the onset of eruptions that are triggered by flux emergence, and calls for a detailed survey of the relevant parameter space by means of numerical simulations.
| Type: | Article |
|---|---|
| Title: | Sequential Eruptions Triggered by Flux Emergence: Observations and Modeling |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.3847/1538-4357/aacce3 |
| Publisher version: | https://doi.org/10.3847/1538-4357/aacce3 |
| Language: | English |
| Additional information: | Original content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence (http://creativecommons.org/licenses/by/3.0). Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. |
| Keywords: | Sun: corona, Sun: coronal mass ejections (CMEs), Sun: magnetic fields |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Space and Climate Physics |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10055340 |
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