The How and Why of Big Solar Flares
Abstract
It is generally understood that the peak soft X-ray flux of solar flares emanating from active regions follows a power-law spectrum of magnitudes; however, it is not understood why the flares from some active regions do not obviously exhibit this distribution. We take here an approach to understand why this occurs, by combining modeling and observation to study the energy reservoirs within a solar active region and the pathway the energy takes to produce solar events. We consider a complex active region, NOAA AR 11793 from July 19th, 2013, that was expected to produce larger flares than the actual C-flares observed. We modeled the coronal magnetic field using the CFITS nonlinear force-free extrapolation code, then identified individual current systems by starting from photospheric concentrations of current and propagating those through the extrapolation volume. We estimated the energy-release prospects of each current system as a measure of how much energy might be released in a single reconnection event. We investigated different ways of determining the current systems to investigate the sensitivity of the results to the choice of current systems. We present here results comparing the energy associated with the individual current systems with the magnitude of the flares originating from our region.
This material is based upon work supported by the US National Science Foundation REU program under Award No. 1659878, and NSF Grant No. 1630454. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation.- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMSH31D3336I
- Keywords:
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- 7519 Flares;
- SOLAR PHYSICS;
- ASTROPHYSICS;
- AND ASTRONOMY;
- 7524 Magnetic fields;
- SOLAR PHYSICS;
- ASTROPHYSICS;
- AND ASTRONOMY;
- 7924 Forecasting;
- SPACE WEATHER;
- 7959 Models;
- SPACE WEATHER