| Presentation Title: | Tracking Magnetic Structures That Are Reconnecting or Expanding or Both |
| Author(s): | J. Qiu, D. Longcope, D. Osaben |
Abstract:
Explosive energy release in the solar atmosphere is driven magnetically, but mechanisms triggering the onset of the eruption remain in debate. In the case of flares and CMEs, ideal or non-ideal instabilities usually occur in the corona, but direct observations and diagnostics there are difficult to obtain. To overcome this difficulty, we analyze observational signatures in the upper chromosphere or transition region, in particular, brightenings and dimmings at the feet of coronal magnetic structures. In this study, we examine the time evolution of spatially resolved light curves in several eruptive flares, and identify a variety of tempo-spatial sequences of brightenings and dimmings, such as dimming followed by brightening, and dimming preceded by brightening. These brightening-dimming sequences are indicative of the configuration of energy release in the form of plasma heating or bulk motion, either or both of which may result from reconnection. We demonstrate the potential of using these analyses to diagnose properties of magnetic reconnection and plasma expansion in the corona, and to infer magnetic configuration of the corona prior to eruption, and during the early phase of eruption.