title: Investigation into the dual role of shear flow in 2D MHD turbulence.
abstract: The turbulent diffusion eta_{T} of a large-scale magnetic field B0 is numerically studied in two-dimensional magnetohydrodynamic turbulence with an imposed shear flow. We demonstrate that a shear flow plays a dual role, quenching transport through shear destruction and enhancing it via resonance. Specifically without resonance eta_{T} proportional, variantB_{0};{-4} with no shear (rms shearing rate=Omega=0) and eta_{T} proportional, variantOmega;{-2.7} for B_{0}=0, while with resonance eta_{T} proportional, variantB_{0};{-2} proportional, variantOmega;{-2}. These results indicate that the absence of resonance is responsible for the most catastrophic reductions in transport.
authors.affiliation: Department of Applied Mathematics, University of Sheffield, Sheffield, S3 7RH, United Kingdom.
authors.forename: Andrew P L
authors.initials: AP
authors.lastname: Newton
authors.forename: Eun-Jin
authors.initials: EJ
authors.lastname: Kim