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Title: EVIDENCE FOR SOLAR TETHER-CUTTING MAGNETIC RECONNECTION FROM CORONAL FIELD EXTRAPOLATIONS

Abstract

Magnetic reconnection is one of the primary mechanisms for triggering solar eruptive events, but direct observation of this rapid process has been a challenge. In this Letter, using a nonlinear force-free field (NLFFF) extrapolation technique, we present a visualization of field line connectivity changes resulting from tether-cutting reconnection over about 30 minutes during the 2011 February 13 M6.6 flare in NOAA AR 11158. Evidence for the tether-cutting reconnection was first collected through multiwavelength observations and then by analysis of the field lines traced from positions of four conspicuous flare 1700 Å footpoints observed at the event onset. Right before the flare, the four footpoints are located very close to the regions of local maxima of the magnetic twist index. In particular, the field lines from the inner two footpoints form two strongly twisted flux bundles (up to ∼1.2 turns), which shear past each other and reach out close to the outer two footpoints, respectively. Immediately after the flare, the twist index of regions around the footpoints diminishes greatly and the above field lines become low-lying and less twisted (≲0.6 turns), overarched by loops linking the two flare ribbons formed later. About 10% of the flux (∼3 × 10{sup 19} Mx)more » from the inner footpoints undergoes a footpoint exchange. This portion of flux originates from the edge regions of the inner footpoints that are brightened first. These rapid changes of magnetic field connectivity inferred from the NLFFF extrapolation are consistent with the tether-cutting magnetic reconnection model.« less

Authors:
; ; ;  [1];  [2]
  1. Space Weather Research Laboratory, Center for Solar-Terrestrial Research, New Jersey Institute of Technology, University Heights, Newark, NJ 07102-1982 (United States)
  2. Max-Planck-Institut für Sonnensystemforschung, Max-Planck-Strasse 2, D-37191 Katlenburg-Lindau (Germany)
Publication Date:
OSTI Identifier:
22364106
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal Letters
Additional Journal Information:
Journal Volume: 778; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 2041-8205
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ASTROPHYSICS; EXTRAPOLATION; INDEXES; MAGNETIC FIELDS; MAGNETIC RECONNECTION; NONLINEAR PROBLEMS; SHEAR; SOLAR FLARES; SUN

Citation Formats

Liu, Chang, Deng, Na, Lee, Jeongwoo, Wang, Haimin, Wiegelmann, Thomas, and Moore, Ronald L., E-mail: chang.liu@njit.edu. EVIDENCE FOR SOLAR TETHER-CUTTING MAGNETIC RECONNECTION FROM CORONAL FIELD EXTRAPOLATIONS. United States: N. p., 2013. Web. doi:10.1088/2041-8205/778/2/L36.
Liu, Chang, Deng, Na, Lee, Jeongwoo, Wang, Haimin, Wiegelmann, Thomas, & Moore, Ronald L., E-mail: chang.liu@njit.edu. EVIDENCE FOR SOLAR TETHER-CUTTING MAGNETIC RECONNECTION FROM CORONAL FIELD EXTRAPOLATIONS. United States. https://doi.org/10.1088/2041-8205/778/2/L36
Liu, Chang, Deng, Na, Lee, Jeongwoo, Wang, Haimin, Wiegelmann, Thomas, and Moore, Ronald L., E-mail: chang.liu@njit.edu. 2013. "EVIDENCE FOR SOLAR TETHER-CUTTING MAGNETIC RECONNECTION FROM CORONAL FIELD EXTRAPOLATIONS". United States. https://doi.org/10.1088/2041-8205/778/2/L36.
@article{osti_22364106,
title = {EVIDENCE FOR SOLAR TETHER-CUTTING MAGNETIC RECONNECTION FROM CORONAL FIELD EXTRAPOLATIONS},
author = {Liu, Chang and Deng, Na and Lee, Jeongwoo and Wang, Haimin and Wiegelmann, Thomas and Moore, Ronald L., E-mail: chang.liu@njit.edu},
abstractNote = {Magnetic reconnection is one of the primary mechanisms for triggering solar eruptive events, but direct observation of this rapid process has been a challenge. In this Letter, using a nonlinear force-free field (NLFFF) extrapolation technique, we present a visualization of field line connectivity changes resulting from tether-cutting reconnection over about 30 minutes during the 2011 February 13 M6.6 flare in NOAA AR 11158. Evidence for the tether-cutting reconnection was first collected through multiwavelength observations and then by analysis of the field lines traced from positions of four conspicuous flare 1700 Å footpoints observed at the event onset. Right before the flare, the four footpoints are located very close to the regions of local maxima of the magnetic twist index. In particular, the field lines from the inner two footpoints form two strongly twisted flux bundles (up to ∼1.2 turns), which shear past each other and reach out close to the outer two footpoints, respectively. Immediately after the flare, the twist index of regions around the footpoints diminishes greatly and the above field lines become low-lying and less twisted (≲0.6 turns), overarched by loops linking the two flare ribbons formed later. About 10% of the flux (∼3 × 10{sup 19} Mx) from the inner footpoints undergoes a footpoint exchange. This portion of flux originates from the edge regions of the inner footpoints that are brightened first. These rapid changes of magnetic field connectivity inferred from the NLFFF extrapolation are consistent with the tether-cutting magnetic reconnection model.},
doi = {10.1088/2041-8205/778/2/L36},
url = {https://www.osti.gov/biblio/22364106}, journal = {Astrophysical Journal Letters},
issn = {2041-8205},
number = 2,
volume = 778,
place = {United States},
year = {Sun Dec 01 00:00:00 EST 2013},
month = {Sun Dec 01 00:00:00 EST 2013}
}