A CRITICAL ASSESSMENT OF NONLINEAR FORCE-FREE FIELD MODELING OF THE SOLAR CORONA FOR ACTIVE REGION 10953

By M. DeRosa, C. Schrijver, G. Barnes, K. Leka, B. Lites, Markus J. Aschwanden, Tahar Amari, A. Canou, J. McTiernan, S. Régnier and 9 more. 2009

313 citations recorded by the source corpus.

Nonlinear force-free field (NLFFF) models are thought to be viable tools for investigating the structure, dynamics, and evolution of the coronae of solar active regions. In a series of NLFFF modeling studies, we have found that NLFFF models are successful in application to analytic test cases, and relatively successful when applied to numerically constructed Sun-like test cases, but they are less successful in application to real solar data. Different NLFFF models have been found to have markedly different field line configurations and to provide widely varying estimates of the magnetic free energy in the coronal volume, when applied to solar data. NLFFF models require consistent, force-free vector magnetic boundary data. However, vector magnetogram observations sampling the photosphere, which is dynamic and contains significant Lorentz and buoyancy forces, do not satisfy this requirement, thus creating several major problems for force-free coronal modeling efforts. In this paper, we discuss NLFFF modeling of NOAA Active Region 10953 using Hinode/SOT–SP, Hinode/XRT, STEREO/SECCHI–EUVI, and SOHO/MDI observations, and in the process illustrate three such issues we judge to be critical to the success of NLFFF modeling: (1) vector magnetic field data covering larger areas are needed so that more electric currents associated with the full active regions of interest are measured, (2) the modeling algorithms need a way to accommodate the various uncertainties in the boundary data, and (3) a more realistic physical model is needed to approximate the photosphere-to-corona interface in order to better transform the forced photospheric magnetograms into adequate approximations of nearly force-free fields at the base of the corona. We make recommendations for future modeling efforts to overcome these as yet unsolved problems.

Subfields: Astronomy and Astrophysics, Molecular Biology

View Paper: https://www.semanticscholar.org/paper/eac8a6e1d0eb5acf07b3df3fd1d3c1438e53be2e

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

In Molecular Biology

Citations in the corpus

Solar Force-free Magnetic Fields (2012, methodology): “In DeRosa et al. (2009) it was concluded that successful application to real solar data likely requires at least:”
EVOLUTION OF MAGNETIC FIELD AND ENERGY IN A MAJOR ERUPTIVE ACTIVE REGION BASED ON SDO/HMI OBSERVATION (2011, background): “We note that a series of comparative and diagnostic efforts pointed out the difficulties in employing realistic data input for NLFFF extrapolation (e.g Schrijver et al. 2008; DeRosa et al. 2009).”
How Should One Optimize Nonlinear Force-Free Coronal Magnetic Field Extrapolations from SDO/HMI Vector Magnetograms? (2012, methodology): “While stereoscopic reconstructed loops in 3D as used in (DeRosa et al., 2009; Conlon and Gallagher, 2010) are not available, we compare our results with an AIA-image from one viewpoint.”
CORONAL LOOP OSCILLATIONS OBSERVED WITH ATMOSPHERIC IMAGING ASSEMBLY—KINK MODE WITH CROSS-SECTIONAL AND DENSITY OSCILLATIONS (2011, background): “…models, but both are known to show misalignments with the 3D geometry of stereoscopically triangulated loops of the order of αmis ≈ 20◦–40◦ (DeRosa et al. 2009; Sandman et al. 2009), while simple potential-field models calculated from a small set of unipolar magnetic charges…”
COEXISTING FLUX ROPE AND DIPPED ARCADE SECTIONS ALONG ONE SOLAR FILAMENT (2010, background): “But this would yield an inconsistent boundary for a nonlinear force-free model, since the LOS fields do not contain any currents to provide the information for the correct field line connections (DeRosa et al. 2009).”