The Three-Dimensional Structure of a Sunspot Magnetic Field
  Here we report on observations of the three-dimensional structure of a sunspot magnetic field from the photosphere to the chromosphere, obtained with the new visible/infrared spectro-polarimeter SPINOR. The observations, interpreted with a non-LTE modeling technique, reveal a surprisingly complex topology with areas of opposite-sign torsion, suggesting that flux-ropes of opposite helicities may coexist together in the same spot. 
H. Socas-Navarro