Magnetic Energies in Solar Active Regions and Flares Calculated from Automated Coronal Loop Tracing

Monday, 15 December 2014
Markus J Aschwanden, Lockheed Martin Solar and Astrophysics Laboratory, Palo Alto, CA, United States
Magnetic energies contained in solar active regions or dissipated in flares can now be calculated from coronal images (such as from AIA/SDO) and line-of-sight magnetograms (such as from HM I/SDO). The magnetogram provides a potential field solution, while automated tracing of coronal loops in different EUV wavelengths provide the misalignment angles between potential field lines and non-potential field lines. We present an automated code that uses data from AIA and HMI to calculate the free energy and dissipated energy in solar flares, based on a nonlinear force-free field approximation in terms of vertical currents that produce helical twists of coronal loops. We study the time evolution of free energy and energy dissipation during some 200 solar flares and compare it with the global energetics of flare and CME energies. The occurrence frequency distributions of dissipated magnetic energies follow closely the predicted powerlaw distribution functions of self-organized criticality models. The presented results provide for the first time statistics on magnetic energies dissipated in solar flares.