Three-dimensional magnetic reconnection and the magnetic topology of coronal mass ejection events

Showing in four easy and nicely color-coded steps the 3-D evolution of an erupting bipolar field structure. The cartoon starts with two field lines forming a sheared arcade. Later other open field lines are brought in as needed. Note that this is bad cartooning practice. We think all the field lines used ought to be tracked! In principle, given the reconnections shown, one can get each of the three possible field connectivities launched into interplanetary space by a flare/CME eruption. The types are open/open, open/closed, and closed/closed, referring to the physical conditions at either "end" of the given field line. Connectivities can be determined by the distribution functions of the particles observed in a given flux tube; open/open would correspond to the "heat flux dropout" signature, and closed/closed to the "bidirectional streaming" signature.

      Just a comment - note that without the previously-existing open field lines (yellow), the eruption itself cannot result in open field lines except on an MHD time scale. Thus only these reconnections to open field lines could allow particles accelerated in the low corona actually to escape quickly from the Sun. The red line at lower right must be part of a set of measure zero. Finally, what was new in this paper? The basic reconnection scenario was well-known at the time it was written (cf. "CSHKP" and the Anzer-Pneuman cartoon, among many others). Maybe the novelty just was in the expected behavior of the solar wind as dictated by the flare.