Description
Switchbacks are large Alfvénic deflections , or even reversals, of the magnetic field in the solar wind. Many authors have suggested that switchbacks are linked to processes low in the solar atmosphere such as interchange reconnection, but the manner of this connection remains unclear. Torsional Alfvén waves are known to be naturally produced by impulsive interchange reconnection events such as coronal jets and jetlets, as well as chromospheric swirling motions. Here we present a new study of how such Torsional Alfvén waves can evolve into switchbacks in a super-radially expanding solar wind. We find that the waves evolve into a vortex ring configuration (similar to hydrodynamic smoke and bubble rings) involving Alfvénic radial field reversals. We show that the maximum deflection associated with this evolution is relatively insensitive to the injection time or driving speed, provided a sufficient amount of twist is injected in total. Overall, our findings support the idea that Torsional Alfvén waves launched into the solar corona by interchange reconnection or surface swirling motions can provide seed perturbations for the formation of switchback radial field reversals within the solar wind.
