Magneto-static Modeling from Sunrise/IMaX: Application to an Active Region Observed with Sunrise II

T. Wiegelmann, T. Neukirch, D. H. Nickeler, S. K. Solanki, P. Barthol, A. Gandorfer, L. Gizon, J. Hirzberger, T. L. Riethmüller, M. Van Noort, J. Blanco Rodríguez, J. C.Del Toro Iniesta, D. Orozco Suárez, W. Schmidt, V. Martínez Pillet, M. Knölker

Research output: Contribution to journalArticlepeer-review


Magneto-static models may overcome some of the issues facing force-free magnetic field extrapolations. So far they have seen limited use and have faced problems when applied to quiet-Sun data. Here we present a first application to an active region. We use solar vector magnetic field measurements gathered by the IMaX polarimeter during the flight of the Sunrise balloon-borne solar observatory in 2013 June as boundary conditions for a magneto-static model of the higher solar atmosphere above an active region. The IMaX data are embedded in active region vector magnetograms observed with SDO/HMI. This work continues our magneto-static extrapolation approach, which was applied earlier to a quiet-Sun region observed with Sunrise I. In an active region the signal-to-noise-ratio in the measured Stokes parameters is considerably higher than in the quiet-Sun and consequently the IMaX measurements of the horizontal photospheric magnetic field allow us to specify the free parameters of the model in a special class of linear magneto-static equilibria. The high spatial resolution of IMaX (110-130 km, pixel size 40 km) enables us to model the non-force-free layer between the photosphere and the mid-chromosphere vertically by about 50 grid points. In our approach we can incorporate some aspects of the mixed beta layer of photosphere and chromosphere, e.g., taking a finite Lorentz force into account, which was not possible with lower-resolution photospheric measurements in the past. The linear model does not, however, permit us to model intrinsic nonlinear structures like strongly localized electric currents.

Original languageEnglish (US)
Article number18
JournalAstrophysical Journal, Supplement Series
Issue number1
StatePublished - Mar 2017


  • Sun: chromosphere
  • Sun: corona
  • Sun: magnetic fields
  • Sun: photosphere

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


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