Evolution of coronal magnetic fields

• Applicant: Dr. Thomas Wiegelmann
• Subject Area: Astrophysics and Astronomy
• Term: from 2010 to 2013
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 168925481

Solar eruptions like flares and coronal mass ejections expel a huge amount of energy in the form of radiation and charged particles into the interplanetary space. These cause impressive phenomena at Earth like aurorae but also have harmful effects like the disruption of radio communication, the damage of satellites, and power cutoffs. These eruptions are driven by instabilities of the coronal magnetic field. High-accuracy routine measurements of the magnetic field vector are restricted to the photosphere and one needs to apply extrapolation techniques to reconstruct the coronal magnetic field. Within this work we plan to apply the sophisticated nonlinear force-free approach to compute the three-dimensional coronal magnetic field structure from a series of photospheric vector magnetograms with unprecedented high spacial and temporal resolution. Our aims are on one hand to study the temporal evolution of the magnetic energy, helicity, topology and current sheet formation in the solar corona to understand and predict eruptive phenomena. On the other hand we aim to study the coronal plasma guided by the reconstructed magnetic field lines in order to get insights into physical processes of the coronal plasma, in particular coronal heating.

• DFG Programme: Research Grants