{
  "id": "1502.05941",
  "version": "v1",
  "published": "2015-02-20T17:13:28.000Z",
  "updated": "2015-02-20T17:13:28.000Z",
  "title": "Global Energetics of Solar Flares: II. Thermal Energies",
  "authors": [
    "M. J. Aschwanden",
    "P. Boerner",
    "D. Ryan",
    "A. Caspi",
    "J. M. McTiernan",
    "H. P. Warren"
  ],
  "comment": "Accepted for publication in ApJ, 2015-Feb-18 (in press)",
  "categories": [
    "astro-ph.SR"
  ],
  "abstract": "We present the second part of a project on the global energetics of solar flares and CMEs that includes about 400 M- and X-class flares observed with AIA/SDO during the first 3.5 years of its mission. In this Paper II we compute the differential emission measure (DEM) distribution functions and associated multi-thermal energies, using a spatially-synthesized Gaussian DEM forward-fitting method. The multi-thermal DEM function yields a significantly higher (by an average factor of $\\approx 14$), but more comprehensive (multi-)thermal energy than an isothermal energy estimate from the same AIA data. We find a statistical energy ratio of $E_{th}/E_{diss} \\approx 2\\%-40\\%$ between the multi-thermal energy $E_{th}$ and the magnetically dissipated energy $E_{diss}$, which is an order of magnitude higher than the estimates of Emslie et al.~2012. 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, $n_p=10^{10.3}-10^{11.8}$ cm$^{-3}$ for the average electron density, $EM_p=10^{47.3}-10^{50.3}$ cm$^{-3}$ for the DEM peak emission measure, and $E_{th}=10^{26.8}-10^{32.0}$ erg for the multi-thermal energies. The deduced multi-thermal energies are consistent with the RTV scaling law $E_{th,RTV} = 7.3 \\times 10^{-10} \\ T_p^3 L_p^2$, which predicts extremal values of $E_{th,max} \\approx 1.5 \\times 10^{33}$ erg for the largest flare and $E_{th,min} \\approx 1 \\times 10^{24}$ 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.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2015-02-20T17:13:28.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "solar flares",
      "global energetics",
      "multi-thermal energy",
      "gaussian dem forward-fitting method",
      "rtv scaling law"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}