Forecasting a CME by Spectroscopic Precursor?
Abstract
Multi-temperature plasma flows resulting from the interaction between a mature active region (AR) inside an equatorial coronal hole (CH) are investigated. Outflow velocities observed by Hinode EIS ranged from a few to 13 km s−1 for three days at the AR's eastern and western edges. However, on the fourth day, velocities intensified up to 20 km s−1 at the AR's western footpoint about six hours prior to a CME. 3D MHD numerical simulations of the observed magnetic configuration of the AR-CH complex showed that the expansion of the mature AR's loops drives persistent outflows along the neighboring CH field (Murray et al. in Solar Phys.261, 253, 2010). Based on these simulations, intensification of outflows observed pre-eruption on the AR's western side where same-polarity AR and CH field interface, is interpreted to be the result of the expansion of a sigmoidal AR, in particular, a flux rope containing a filament that provides stronger compression of the neighboring CH field on this side of the AR. Intensification of outflows in the AR is proposed as a new type of CME precursor.
- Publication:
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Solar Physics
- Pub Date:
- February 2012
- DOI:
- 10.1007/s11207-011-9893-4
- Bibcode:
- 2012SoPh..276..219B
- Keywords:
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- Active regions;
- Magnetic fields;
- Coronal mass ejections