Topology of Coronal Fields from Potential Field Models

The topology of the solar coronal magnetic field has been the subject of much recent interest, due to its apparent importance in determining (for example) the sources of the solar wind, the evolution of coronal hole boundaries, and whether the configurations of coronae overlying active regions are unstable and thus possibly eruption-prone. We identify the topological skeleton (null points, spline lines, separators, and separatrix surfaces) for a selection of dates of interest from the database of potential-field source-surface models available through the ``PFSS'' SolarSoft package. Several features of interest have been identified by recent studies (e.g., Antiochos et al. 2007, Parnell et al. 2010, Titov et al. 2011), including exceedingly narrow channels of open field or separators associated with inferred reconnection sites. We find that these features of interest occur frequently in the topologies of even potential-field models of the magnetic corona. The actual solar corona is of course likely to involve even more complex topologies, especially as its dynamics and evolution are taken into account.