TIME EVOLUTION OF CORONAL MAGNETIC HELICITY IN THE FLARING ACTIVE REGION NOAA 10930

Journal Article · Fri Sep 10 00:00:00 EDT 2010 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/720/2/1102· OSTI ID:21460069

Park, Sung-Hong; Jing, Ju; Haimin, Wang ^[1]; Chae, Jongchul ^[2]; Tan, Changyi ^[3]

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1. Space Weather Research Laboratory, New Jersey Institute of Technology, 323 Martin Luther King Boulevard, 101 Tiernan Hall, Newark, NJ 07102 (United States)
2. Astronomy Program and FPRD, Department of Physics and Astronomy, Seoul National University, Seoul 151-742 (Korea, Republic of)
3. IMSG Inc., Camp Springs, MD 20746 (United States)

To study the three-dimensional (3D) magnetic field topology and its long-term evolution associated with the X3.4 flare of 2006 December 13, we investigate the coronal relative magnetic helicity in the flaring active region (AR) NOAA 10930 during the time period of December 8-14. The coronal helicity is calculated based on the 3D nonlinear force-free magnetic fields reconstructed by the weighted optimization method of Wiegelmann, and is compared with the amount of helicity injected through the photospheric surface of the AR. The helicity injection is determined from the magnetic helicity flux density proposed by Pariat et al. using Solar and Heliospheric Observatory/Michelson Doppler Imager magnetograms. The major findings of this study are the following. (1) The time profile of the coronal helicity shows a good correlation with that of the helicity accumulation by injection through the surface. (2) The coronal helicity of the AR is estimated to be -4.3 x 10{sup 43} Mx{sup 2} just before the X3.4 flare. (3) This flare is preceded not only by a large increase of negative helicity, -3.2 x 10{sup 43} Mx{sup 2}, in the corona over {approx}1.5 days but also by noticeable injections of positive helicity through the photospheric surface around the flaring magnetic polarity inversion line during the time period of the channel structure development. We conjecture that the occurrence of the X3.4 flare is involved with the positive helicity injection into an existing system of negative helicity.

• OSTI ID: 21460069
• Journal Information: Astrophysical Journal, Vol. 720, Issue 2; Other Information: DOI: 10.1088/0004-637X/720/2/1102; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
FLARING
FLUX DENSITY
FORCE-FREE MAGNETIC FIELDS
NONLINEAR PROBLEMS
PHOTOSPHERE
SOLAR SYSTEM EVOLUTION
STAR EVOLUTION
SUN
THREE-DIMENSIONAL CALCULATIONS
TOPOLOGY
ATMOSPHERES
EVOLUTION
MAGNETIC FIELDS
MAIN SEQUENCE STARS
MATHEMATICS
SOLAR ATMOSPHERE
STARS
STELLAR ATMOSPHERES