THE MECHANISMS FOR THE ONSET AND EXPLOSIVE ERUPTION OF CORONAL MASS EJECTIONS AND ERUPTIVE FLARES

Journal Article · Tue Nov 20 04:00:00 EST 2012 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/760/1/81· OSTI ID:22086279

Karpen, J T; Antiochos, S K ^[1]; DeVore, C R ^[2]

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1. Code 674, NASA GSFC, Greenbelt, MD 20771 (United States)
2. Code 6042, NRL, Washington, DC 20375 (United States)

We have investigated the onset and acceleration of coronal mass ejections (CMEs) and eruptive flares. To isolate the eruption physics, our study uses the breakout model, which is insensitive to the energy buildup process leading to the eruption. We performed 2.5D simulations with adaptive mesh refinement that achieved the highest overall spatial resolution to date in a CME/eruptive flare simulation. The ultra-high resolution allows us to separate clearly the timing of the various phases of the eruption. Using new computational tools, we have determined the number and evolution of all X- and O-type nulls in the system, thereby tracking both the progress and the products of reconnection throughout the computational domain. Our results show definitively that CME onset is due to the start of fast reconnection at the breakout current sheet. Once this reconnection begins, eruption is inevitable; if this is the only reconnection in the system, however, the eruption will be slow. The explosive CME acceleration is triggered by fast reconnection at the flare current sheet. Our results indicate that the explosive eruption is caused by a resistive instability, not an ideal process. Moreover, both breakout and flare reconnections begin first as a form of weak tearing characterized by slowly evolving plasmoids, but eventually transition to a fast form with well-defined Alfvenic reconnection jets and rapid flux transfer. This transition to fast reconnection is required for both CME onset and explosive acceleration. We discuss the key implications of our results for CME/flare observations and for theories of magnetic reconnection.

• OSTI ID: 22086279
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 760; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ACCELERATION
ALFVEN WAVES
ASTROPHYSICS
COMPUTERIZED SIMULATION
ELECTRIC CURRENTS
MAGNETIC FIELDS
MAGNETIC RECONNECTION
MAGNETOHYDRODYNAMICS
MASS
PLASMA SIMULATION
PLASMOIDS
SOLAR CORONA
SOLAR FLARES
SPATIAL RESOLUTION
SUN