Abstract


  FORCE-FREE FIELDS: FROM PHOTOSPHERE TO CORONA

  A. Mangalam, Indian Institute of Astrophysics, mangalam@iiap.res.in
  A. Prasad, Indian Institute of Astrophysics, avijeet@iiap.res.in

Classical solutions of the axisymmetric and non-linear force-free fields  in
spherical geometry are applied to photospheric vector magnetograms
obtained from HINODE. Fits to the vector magnetograms are used to build
the full 3D field configurations of the magnetic field from which the
free energy and relative helicity are computed.  The variation of twist
angle is also studied as a function of altitude. General solutions to
non-axisymmetric non-linear force-free fields are also explored.