Scaling laws and frequency distributions of avalanche areas in a self-organized criticality model of solar flares.

MORALES, L. F.; CHARBONNEAU, P.

GEOPHYSICAL RESEARCH LETTERS

AMER GEOPHYSICAL UNION

Lugar: Washington; Año: 2008 vol. 35 p. 4108 - 4112

0094-8276

We calculate the spreading exponents and some geometrical properties of avalanches in a novel avalanche model of solar flares, closely built on Parker´s physical picture of coronal heating by nanoflares. The model is based on an idealized representation of a coronal loop as a bundle of magnetic flux strands wrapping around one another, numerically implemented as an anisotropic cellular automaton. We demonstrate that the growth of avalanches in this model exhibits power-laws correlations that are numerically consistent with the behavior of a general class of statistical physical systems in the vicinity of a stationary critical point. This demonstrates that the model indeed operates in a self-organized critical regime. Moreover, we find that the frequency distribution of avalanche peak areas A assumes a power-law form f(A) ∝ with an index αA ≃ 2.45, in excellent agreement with observationally-inferred values.