The Kelvin–Helmholtz instability, differential rotation, and three-dimensional, localized, magnetic reconnection

Abstract

Results are presented from a study of three-dimensional magnetic reconnection caused by a Kelvin–Helmholtz instability and differential rotation. Specifically, subsonic and sub-Alfvénic flow is considered, which is Kelvin–Helmholtz stable in the direction of the magnetic field, but unstable perpendicular to the magnetic field. The flow is modeled by the resistive magnetohydrodynamics equations in three dimensions with constant resistivity. As a result of differential rotation (a gradient in vorticity parallel to the initial field), localized transient reconnection is observed on the Kelvin–Helmholtz time scale. Current amplification is observed along with the generation of parallel current. Results indicate that the observed transient reconnection rate is insensitive to resistivity (even with a constant resistivity model), but is sensitive to the initial flow shear.