Submission_time: 2013/04/19 12:57 EST

Badge_Name:Manolis K. Georgoulis

Affiliation:RCAAM of the Academy of Athens

Working_Group 1st Choice:WG1

Working_Group 2nd Choice:WG2

Title:Nonlinear force-free energy and helicity budgets in solar active regions as proxies of their pre-eruption evolution

Abstract:Via a recently published technique we can perform routine nonlinear force-free calculations of the magnetic energy and relative magnetic helicity budgets in solar active regions using only a single photospheric vector magnetogram of a given region. The method does not require three-dimensional field extrapolations. Timeseries of vector magnetograms lead to pseudo-timeseries of the energy and helicity budgets, by means of which we study the evolution of the region in question. In case of eruptive activity in the course of this evolution we can detect budget changes that we interpret as related to the eruption(s). Examples of the technique are given using SDO/HMI vector magnetograms. Some of the results are particularly highlighted, as they imply a consistent, coherent physical picture of the pre-eruption evolution in active regions. To stimulate discussion in the framework of this workshop we study the near-Sun evolution of at least one source active region with a CME leading to an ICME included in the ISEST ICME list.

Comments:I would appreciate an opportunity to present this in an oral presentation. Hopefully I should be able to contribute to the workshop's deliberations and discussion.