2D Cellular Automaton Model for Coronal Loop Dynamics

M. C. LÓPEZ FUENTES; J. A. KLIMCHUK

Palma de Mallorca

Workshop; Fifth Coronal Loops Workshop; 2011

  We present a coronal loop model based on a 2D cellular automaton approach. Following Parker'ssuggestion (1988, ApJ, 330, 474), loops are assumed to be formed by a number of elemental strandsthat interact with each other, so that accumulated magnetic energy due to strand footpointdisplacements is released in small scale reconnection events (or nanoflares). The more sophisticated 2Dversion presented here is loosely based on the 1D version developed in Lopez-Fuentes & Klimchuk(2010, ApJ, 719, 591). The model consists of a 2D grid in which strand photospheric footpoints travelwith random displacements simulating convective motions. Each time two strands interact, a criticalcondition is tested (as in self-organized critical models), and if the condition is fulfilled, strandsreconnect and energy is released. We model the plasma response to the resulting heating using theEBTEL code (Klimchuk et al. 2008, ApJ, 682, 1351). Finally, we obtain synthetic observations bycombining the evolving plasma density and temperature from EBTEL with the known response ofdifferent instruments. We compare the output of the model with real observations from SDO/AIA andHinode/XRT and discuss the implications of our results for coronal heating.