δ-SUNSPOT FORMATION IN SIMULATION OF ACTIVE-REGION-SCALE FLUX EMERGENCE
Journal Article
·
· Astrophysical Journal
- High Altitude Observatory, National Center for Atmospheric Research, 3090 Center Green Drive, Boulder, CO 80301 (United States)
δ-sunspots, with highly complex magnetic structures, are very productive in energetic eruptive events, such as X-class flares and homologous eruptions. We here study the formation of such complex magnetic structures by numerical simulations of magnetic flux emergence from the convection zone into the corona in an active-region-scale domain. In our simulation, two pairs of bipolar sunspots form on the surface, originating from two buoyant segments of a single subsurface twisted flux rope, following the approach of Toriumi et al. Expansion and rotation of the emerging fields in the two bipoles drive the two opposite polarities into each other with apparent rotating motion, producing a compact δ-sunspot with a sharp polarity inversion line. The formation of the δ-sunspot in such a realistic-scale domain produces emerging patterns similar to those formed in observations, e.g., the inverted polarity against Hale's law, the curvilinear motion of the spot, and strong transverse field with highly sheared magnetic and velocity fields at the polarity inversion line (PIL). Strong current builds up at the PIL, giving rise to reconnection, which produces a complex coronal magnetic connectivity with non-potential fields in the δ-spot overlaid by more relaxed fields connecting the two polarities at the two ends.
- OSTI ID:
- 22522321
- Journal Information:
- Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 806; ISSN ASJOAB; ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
Similar Records
SUNSPOT ROTATION AS A DRIVER OF MAJOR SOLAR ERUPTIONS IN THE NOAA ACTIVE REGION 12158
RAPID SUNSPOT ROTATION ASSOCIATED WITH THE X2.2 FLARE ON 2011 FEBRUARY 15
A solar eruption driven by rapid sunspot rotation
Journal Article
·
Tue Sep 20 00:00:00 EDT 2016
· Astrophysical Journal
·
OSTI ID:22667420
RAPID SUNSPOT ROTATION ASSOCIATED WITH THE X2.2 FLARE ON 2011 FEBRUARY 15
Journal Article
·
Sat Dec 31 23:00:00 EST 2011
· Astrophysical Journal
·
OSTI ID:22004332
A solar eruption driven by rapid sunspot rotation
Journal Article
·
Tue Apr 01 00:00:00 EDT 2014
· Astrophysical Journal
·
OSTI ID:22357233