MULTI-WAVELENGTH OBSERVATIONS OF THE SPATIO-TEMPORAL EVOLUTION OF SOLAR FLARES WITH AIA/SDO. I. UNIVERSAL SCALING LAWS OF SPACE AND TIME PARAMETERS

We extend a previous statistical solar flare study of 155 GOES M- and X-class flares observed with AIA/SDO to all seven coronal wavelengths (94, 131, 171, 193, 211, 304, and 335 angstrom) to test the wavelength dependence of scaling laws and statistical distributions. Except for the 171 and 193 angstrom 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, and fractal dimension D-2), temporal (flare durations T), and spatio-temporal parameters (diffusion coefficient kappa, spreading exponent beta, and maximum expansion velocities nu(max)) 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) proportional to L-3, N(A) proportional to A(-2), N(V) proportional to V-5/3, N(T) proportional to T-2, and D-2 = 3/2, for a Euclidean dimension d = 3. Empirically, we find also a new strong correlation kappa proportional to L-0.94 +/- 0.01 and the three-parameter scaling law L proportional to kappa T-0.1, 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).