Magnetic Reconnection in the Corona as a Source of Switchbacks in the Solar Wind

The observations from the Parker Solar Probe during the firstperihelion revealed large numbers of local reversals in the radialcomponent of the magnetic field with associated velocity spikes. Sincethe spacecraft was magnetically connected to a coronal hole during theclosest approach to the sun, one possible source of these spikes ismagnetic reconnection between the open field lines in the coronal holeand an adjacent region of closed flux. Reconnection in a low betaenvironment characteristic of the corona is expected to be burstyrather than steady and is therefore capable of producing large numbersof magnetic flux ropes with local reversals of the radial magneticfield that can propagate outward large radial distances from thesun. Flux ropes with a strong guide field produce signaturesconsistent with the PSP observations. We have carried out simulationsof "interchange" reconnection in the corona and have explored thelocal structure of flux ropes embedded within the expanding solarwind. We have first established that traditional interchangereconnection cannot produce the switchbacks since bent field linesgenerated in the corona quickly straighten. The simulations have beenextended to the regime dominated by the production of multiple fluxropes and we have established that flux ropes are injected into thelocal solar wind. Local simulations of reconnection are also beingcarried out to explore the structure of flux ropes embedded in thesolar wind for comparison with observations. Evidence is presentedthat flux rope merging may be ongoing and might lead to the highaspect ratio of the switchback structures measured in the solar wind.