Global Energetics of Solar Flares. V. Energy Closure in Flares and Coronal Mass Ejections

Journal Article · Fri Feb 10 04:00:00 EST 2017 · Astrophysical Journal

DOI:https://doi.org/10.3847/1538-4357/836/1/17· OSTI ID:22869253

Aschwanden, Markus J. ^[1]; Caspi, Amir ^[2]; Cohen, Christina M. S.; Mewaldt, Richard A. ^[3]; Holman, Gordon ^[4]; Jing, Ju; Xu, Yan ^[5]; Kretzschmar, Matthieu ^[6]; Kontar, Eduard P. ^[7]; McTiernan, James M. ^[8]; O’Flannagain, Aidan ^[9]; Richardson, Ian G. ^[10]; Ryan, Daniel ^[11]

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1. Lockheed Martin, Solar and Astrophysics Laboratory, Org. A021S, Building 252, 3251 Hanover Street, Palo Alto, CA 94304 (United States)
2. Planetary Science Directorate, Southwest Research Institute, Boulder, CO 80302 (United States)
3. California Institute of Technology, Mail Code 290-17, Pasadena, CA 91125 (United States)
4. Code 671, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)
5. Space Weather Research Laboratory, Center for Solar–Terrestrial Research, New Jersey Institute of Technology, 323 Martin Luther King Blvd., Newark, NJ 07102-1982 (United States)
6. LPC2E, UMR 6115 CNRS and University of Orléans, 3a Avenue de la recherche scientifique, F-45071 Orléans (France)
7. School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom)
8. Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States)
9. Astrophysics Research Group, School of Physics, Trinity College Dublin, Dublin 2 (Ireland)
10. GPHI and Dept. of Astronomy, University of Maryland, Code 672, NASA Goddard Space Flight Center, Greenbelt, MD 20770 (United States)
11. NASA Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, MD 20770 (United States)

In this study we synthesize the results of four previous studies on the global energetics of solar flares and associated coronal mass ejections (CMEs), which include magnetic, thermal, nonthermal, and CME energies in 399 solar M- and X-class flare events observed during the first 3.5 yr of the Solar Dynamics Observatory (SDO) mission. Our findings are as follows. (1) The sum of the mean nonthermal energy of flare-accelerated particles (E{sub nt}), the energy of direct heating (E{sub dir}), and the energy in CMEs (E{sub CME}), which are the primary energy dissipation processes in a flare, is found to have a ratio of (E{sub nt}+E{sub dir}+E{sub CME})/E{sub mag}=0.87±0.18, compared with the dissipated magnetic free energy E{sub mag}, which confirms energy closure within the measurement uncertainties and corroborates the magnetic origin of flares and CMEs. (2) The energy partition of the dissipated magnetic free energy is: 0.51 ± 0.17 in nonthermal energy of ⩾6 keV electrons, 0.17 ± 0.17 in nonthermal ⩾1 MeV ions, 0.07 ± 0.14 in CMEs, and 0.07 ± 0.17 in direct heating. (3) The thermal energy is almost always less than the nonthermal energy, which is consistent with the thick-target model. (4) The bolometric luminosity in white-light flares is comparable to the thermal energy in soft X-rays (SXR). (5) Solar energetic particle events carry a fraction ≈0.03 of the CME energy, which is consistent with CME-driven shock acceleration. (6) The warm-target model predicts a lower limit of the low-energy cutoff at e{sub c}≈6 keV, based on the mean peak temperature of the differential emission measure of T {sub e} = 8.6 MK during flares. This work represents the first statistical study that establishes energy closure in solar flare/CME events.

• OSTI ID: 22869253
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 836; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ACCELERATION
BOLOMETERS
COMPARATIVE EVALUATIONS
ELECTRONS
EMISSION
ENERGY LOSSES
FREE ENERGY
GAMMA RADIATION
HEATING
KEV RANGE 01-10
LUMINOSITY
MASS
MEV RANGE
SOFT X RADIATION
SOLAR FLARES
SUN
ULTRAVIOLET RADIATION