Nonlinear Force-free Field Modeling of a Solar Active Region around the Time of a Major Flare and Coronal Mass Ejection

By C. Schrijver, M. DeRosa, T. Metcalf, G. Barnes, B. Lites, T. Tarbell, J. McTiernan, G. Valori, T. Wiegelmann, M. Wheatland and 7 more. 2007

269 citations recorded by the source corpus.

Solar flares and coronal mass ejections are associated with rapid changes in field connectivity and are powered by the partial dissipation of electrical currents in the solar atmosphere. A critical unanswered question is whether the currents involved are induced by the motion of preexisting atmospheric magnetic flux subject to surface plasma flows or whether these currents are associated with the emergence of flux from within the solar convective zone. We address this problem by applying state-of-the-art nonlinear force-free field (NLFFF) modeling to the highest resolution and quality vector-magnetographic data observed by the recently launched Hinode satellite on NOAA AR 10930 around the time of a powerful X3.4 flare. We compute 14 NLFFF models with four different codes and a variety of boundary conditions. We find that the model fields differ markedly in geometry, energy content, and force-freeness. We discuss the relative merits of these models in a general critique of present abilities to model the coronal magnetic field based on surface vector field measurements. For our application in particular, we find a fair agreement of the best-fit model field with the observed coronal configuration, and argue (1) that strong electrical currents emerge together with magnetic flux preceding the flare, (2) that these currents are carried in an ensemble of thin strands, (3) that the global pattern of these currents and of field lines are compatible with a large-scale twisted flux rope topology, and (4) that the ~1032 erg change in energy associated with the coronal electrical currents suffices to power the flare and its associated coronal mass ejection.

Subfields: Astronomy and Astrophysics, Molecular Biology

View Paper: https://www.semanticscholar.org/paper/a1245583aaa7023f760f34bcdeabc96ab127d6ef

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Citations in the corpus

EVOLUTION OF MAGNETIC FIELD AND ENERGY IN A MAJOR ERUPTIVE ACTIVE REGION BASED ON SDO/HMI OBSERVATION (2011, background): “These values are typical for this optimization-based algorithm and are comparable to previously reported results based on other solar data sets (e.g. Schrijver et al. 2008).”
Estimating the frequency of extremely energetic solar events, based on solar, stellar, lunar, and terrestrial records (2012, background): “…with a characteristic mean field strength of B0 can be converted into what eventually is radiated from the flare site [e.g. Metcalf et al., 2005; Schrijver et al., 2008], the typical dimension d0 and magnetic flux Φ0 = B0d 2 0 in such a flaring region are given by d0 = ( 4πEf/f B20 )1/3 ; Φo =…”
Driving major solar flares and eruptions: A review (2008, background): “…is often associated with flaring activity (examples are a statistical study by, e.g., Cui et al. 2007, and individual event studies by Kurokawa et al. 2002, Brooks et al. 2003, Dun et al. 2007, Schrijver et al. 2008, Okamoto et al. 2008, and Lites 2008; also coronal field studies described in Sect.”
How Should One Optimize Nonlinear Force-Free Coronal Magnetic Field Extrapolations from SDO/HMI Vector Magnetograms? (2012, background): “For detailed investigations of these data-sets see (Wiegelmann, Inhester, and Sakurai, 2006; Schrijver et al., 2008; Thalmann, Wiegelmann, and Raouafi, 2008), respectively.”
The Origin, Early Evolution and Predictability of Solar Eruptions (2018, background): “First, rise profiles of eruptions sometimes clearly show two distinct phases that cannot be fitted with one functional form (see Section 2.1.2 and e.g., Sterling et al, 2007a,b; Schrijver et al, 2008b), indicating the occurrence of two distinct physical mechanisms.”
A CRITICAL ASSESSMENT OF NONLINEAR FORCE-FREE FIELD MODELING OF THE SOLAR CORONA FOR ACTIVE REGION 10953 (2009, methodology): “It is interesting to note that for AR 10953, as for the Schrijver et al. (2008) case, the solutions bearing the bestresemblance to the Hinode/XRT loops, and here were among the best at matching the STEREO-loop trajectories, were calculated using the current-field iteration method.”
An Observational Overview of Solar Flares (2011, background): “…example, incorporating linear force-free fields (Demoulin et al. 1994) and non-linear force-free fields (Régnier et al. 2002; Régnier & Canfield 2006; Schrijver et al. 2008), and using increasingly precise representations of the photospheric field (Barnes et al. 2005) and chromospheric magnetic…”
The magnetic field in the solar atmosphere (2014, background): “The corresponding numerical implementations have been intensively reviewed, and repeatedly evaluated and improved within the last decade (see Schrijver et al. 2006; Metcalf et al. 2008; Schrijver et al. 2008; De Rosa et al. 2009).”
GLOBAL ENERGETICS OF THIRTY-EIGHT LARGE SOLAR ERUPTIVE EVENTS (2012, background): “…with MDI line-of-sight (LOS) magnetograms (Bobra et al. 2008); and (3) MHD modeling (Metcalf et al. 1995; Jiao et al. 1997) and non-potential field extrapolation based upon photospheric vector magnetograms (Guo et al. 2008; Schrijver et al. 2008; Thalmann & Wiegelmann 2008; Thalmann et al. 2008).”
Magnetic Reconnection in Astrophysical and (2009, background): “For a discussion of extrapolation of photospheric field measurements see Schrijver et al. (2008).”
Solar Force-free Magnetic Fields (2012, methodology): “Schrijver et al. (2008) used four different codes and a variety of boundary conditions to compute 14 NLFFF models based on Hinode/SOT-SP3 data of an active region around the time of a powerful flare.”