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Description
We present the second part of a project on the global energetics of solar flares and coronal mass ejections that includes about 400 M- and X-class flares observed with the Atmospheric Imaging Assembly (AIA) onboard the Solar Dynamics Observatory (SDO) during the first 3.5yr of its mission. In this Paper II we compute the differential emission measure (DEM) distribution functions and associated multithermal energies, using a spatially-synthesized Gaussian DEM forward-fitting method. The multithermal DEM function yields a significantly higher (by an average factor of ~14), but more comprehensive (multi-) thermal energy than an isothermal energy estimate from the same AIA data. We find a statistical energy ratio of E_th_/E_diss_~2-40% between the multithermal energy E_th_ and the magnetically dissipated energy E_diss_, which is an order of magnitude higher than the estimates of Emslie et al. (2012ApJ...759...71E). For the analyzed set of M- and X-class flares we find the following physical parameter ranges: L=10^8.2^-10^9.7^cm for the length scale of the flare areas, T_p_=10^5.7^-10^7.4^K for the DEM peak temperature, T_w_=10^6.8^-10^7.6^K for the emission measure-weighted temperature, n_p_=10^10.3^-10^11.8^/cm3 for the average electron density, EM_p_=10^47.3^-10^50.3^/cm3 for the DEM peak emission measure, and E_th_=10^26.8^-10^32.0^erg for the multithermal energies. The deduced multithermal energies are consistent with the RTV scaling law E_th,RTV_=73x10^-10^T_p_^3^L_p_^2^, which predicts extremal values of E_th,max_~1.5x10^33^erg for the largest flare and E_th,min_~1x10^24^erg for the smallest coronal nanoflare. The size distributions of the spatial parameters exhibit powerlaw tails that are consistent with the predictions of the fractal-diffusive self-organized criticality model combined with the RTV scaling law.
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