Understanding the magnetic topology and reconfiguration of the early stages of solar eruptions by investigating coronal dimmings
Abstract
Coronal dimmings are temporary regions of strongly reduced coronal emission in extreme-ultraviolet (EUV) and soft X-rays that form in the wake of coronal mass ejections (CMEs). In general, their formation is interpreted as density depletion due to the expansion and evacuation of plasma during the early CME evolution. Recently, strong statistical relationships between decisive dimming parameters and CME and flare quantities were derived (Dissauer et al. 2018b, 2019). Using a newly developed detection algorithm, so far not resolved fine structure within the dimming region could be identified for the first time (Dissauer et al. 2018a). Both aspects verify the importance of coronal dimmings in the early diagnostics of solar eruptions. In order to exploit this potential further, we analyze the X2.1 flare/CME event on September 6, 2011 by combining EUV observations of coronal dimmings in SDO/AIA with non-force-free magnetic field modeling. The pre- and post-eruptive magnetic field configurations at the observed coronal dimming locations are investigated, with respect to the coronal dimming fine structure and its intensity distribution. The dynamics of the dimming evolution is studied in the form of timing maps, which code when each pixel of the dimming region is detected for the first time. These timing maps are used to investigate the initiation of the eruption and to identify which flux systems are involved. Coronal dimming locations are also compared with squashing factor Q maps, indicating locations in favor of magnetic reconnection, in order to check whether preferential locations for the formation of coronal dimmings exist prior to the eruption.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMSH32A..04D
- Keywords:
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- 7509 Corona;
- SOLAR PHYSICS;
- ASTROPHYSICS;
- AND ASTRONOMY;
- 7513 Coronal mass ejections;
- SOLAR PHYSICS;
- ASTROPHYSICS;
- AND ASTRONOMY;
- 7524 Magnetic fields;
- SOLAR PHYSICS;
- ASTROPHYSICS;
- AND ASTRONOMY;
- 7959 Models;
- SPACE WEATHER