TESTS OF DYNAMICAL FLUX EMERGENCE AS A MECHANISM FOR CORONAL MASS EJECTION INITIATION
- College of Science, George Mason University, 4400 University Drive, Fairfax, VA 22030 (United States)
- U.S. Naval Research Lab 4555 Overlook Avenue, SW Washington, DC 20375 (United States)
Current coronal mass ejection (CME) models set their lower boundary to be in the lower corona. They do not calculate accurately the transfer of free magnetic energy from the convection zone to the magnetically dominated corona because they model the effects of flux emergence using kinematic boundary conditions or simply assume the appearance of flux at these heights. We test the importance of including dynamical flux emergence in CME modeling by simulating, in 2.5D, the emergence of sub-surface flux tubes into different coronal magnetic field configurations. We investigate how much free magnetic energy, in the form of shear magnetic field, is transported from the convection zone to the corona, and whether dynamical flux emergence can drive CMEs. We find that multiple coronal flux ropes can be formed during flux emergence, and although they carry some shear field into the corona, the majority of shear field is confined to the lower atmosphere. Less than 10% of the magnetic energy in the corona is in the shear field, and this, combined with the fact that the coronal flux ropes bring up significant dense material, means that they do not erupt. Our results have significant implications for all CME models which rely on the transfer of free magnetic energy from the lower atmosphere into the corona but which do not explicitly model this transfer. Such studies of flux emergence and CMEs are timely, as we have new capabilities to observe this with Hinode and the Solar Dynamics Observatory, and therefore to test the models against observations.
- OSTI ID:
- 21471312
- Journal Information:
- Astrophysical Journal, Vol. 722, Issue 1; Other Information: DOI: 10.1088/0004-637X/722/1/550; ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
Similar Records
THE INTERNAL STRUCTURE OF CORONAL MASS EJECTIONS: ARE ALL REGULAR MAGNETIC CLOUDS FLUX ROPES?
A STUDY OF THE BUILD-UP, INITIATION, AND ACCELERATION OF 2008 APRIL 26 CORONAL MASS EJECTION OBSERVED BY STEREO