Multi-Wavelength Observations of the Spatio-Temporal Evolution of Solar Flares with AIA/SDO:I. Universal Scaling Laws of Space and Time Parameters
Markus J. Aschwanden Submitted: 2013-08-22 11:43
We extend a previous statistical solar flare study of 155 GOES
M- and X-class flares observed with AIA/SDO (Aschwanden 2012)
to all 7 coronal wavelengths (94, 131, 171, 193, 211, 304, 335 ang )
to test the wavelength-dependence of scaling laws and statistical
distributions. Except for the 171 and 193 ang wavelengths, which
are affected by EUV dimming caused by coronal mass ejections (CMEs),
we find near-identical
size distributions of geometric (lengths L, flare areas A, volumes
V, fractal dimension D2), temporal (flare durations T), and
spatio-temporal parameters (diffusion coefficient kappa, spreading
exponent eta, and maximum expansion velocities vmax) in
different wavelengths, which are consistent with the universal
predictions of the fractal-diffusive avalanche model of a
slowly-driven self-organized criticality (FD-SOC) system,
i.e., N(L) propto L-3, N(A) propto A-2,
N(V) propto V-5/3, N(T) propto T-2,
D_2=3/2, for a Euclidean dimension d=3.
Empirically we find also a new strong correlation kappa propto
L0.94pm0.01 and the 3-parameter scaling law L propto kappa T0.1,
which is more consistent with the logistic-growth model than with
classical diffusion. The findings suggest long-range correlation
lengths in the FD-SOC system that operate in the vicinity of a critical state,
which could be used for predictions of individual extreme events.
We find also that eruptive flares (with accompanying CMEs),
have larger volumes V, longer flare durations T, higher EUV and
soft X-ray fluxes, and somewhat larger diffusion coefficients kappa
than confined flares (without CMEs).
Authors: Aschwanden,J.M., Zhang, J., Liu,K.
Publication Status: (2013), ApJ 775, 23
Last Modified: 2013-10-07 18:23