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Title: Electric currents in flare ribbons: Observations and three-dimensional standard model

We present for the first time the evolution of the photospheric electric currents during an eruptive X-class flare, accurately predicted by the standard three-dimensional (3D) flare model. We analyze this evolution for the 2011 February 15 flare using Helioseismic and Magnetic Imager/Solar Dynamics Observatory magnetic observations and find that localized currents in J-shaped ribbons increase to double their pre-flare intensity. Our 3D flare model, developed with the OHM code, suggests that these current ribbons, which develop at the location of extreme ultraviolet brightenings seen with Atmospheric Imaging Assembly imagery, are driven by the collapse of the flare's coronal current layer. These findings of increased currents restricted in localized ribbons are consistent with the overall free energy decrease during a flare, and the shapes of these ribbons also give an indication of how twisted the erupting flux rope is. Finally, this study further enhances the close correspondence obtained between the theoretical predictions of the standard 3D model and flare observations, indicating that the main key physical elements are incorporated in the model.
Authors:
 [1] ; ; ; ; ;  [2]
  1. Division of Mathematics, University of Dundee, Dundee DD1 4HN (United Kingdom)
  2. LESIA, Observatoire de Paris, CNRS, UPMC, Univ. Paris Diderot, 5 place Jules Janssen, F-92190 Meudon (France)
Publication Date:
OSTI Identifier:
22356675
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 788; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; EVOLUTION; EXTREME ULTRAVIOLET RADIATION; FREE ENERGY; IMAGES; LAYERS; MAGNETOHYDRODYNAMICS; PHOTOSPHERE; STANDARD MODEL; SUN; THREE-DIMENSIONAL CALCULATIONS