Evolution of the coronal magnetic field of emerging active regions
Solar active regions on the surface of the Sun are the source of dynamic phenomena in the upper atmosphere of the Sun like flares and coronal mass ejections. However, it is not known how these active regions are formed, or how their formation affects the dynamics in the upper atmosphere. Data for close to 180 emerging active regions have been identified and are included in the SDO/Helioseismic and Emerging Active Region survey (Schunker et al. 2016). An important component which has not yet been studied is the vector magnetic field at the surface. The three-dimensional structure of the solar corona above active regions can be reconstructed, using these surface magnetograms, by the assumption of a vanishing Lorentz-force, the so-called force-free assumption (Wiegelmann and Sakurai 2012).
This project concentrates on studying the evolution of the vector magnetic field of active regions and the extension into the atmosphere as they emerge. From this, statistical studies can be done to understand the common physical properties of the emergence process, as well as any significant deviations. Some examples of specific questions that will be answered are:
- What is the orientation of the magnetic field when active regions begin forming?
- At what stage of the surface evolution do loops form?
- How do the loops evolve (twist, height, flux, area, complexity... .)?
- How fast do the loops evolve (height/time, flux/time, current/time, (free) energy etc.)?