Nonlinear evolution of resistive tearing mode with sub-Alfvenic shear flow

Abstract

Nonlinear evolution of resistive tearing mode with different sub-Alfvenic shear flow is investigated using incompressible magnetohydrodynamics simulations. The sub-Alfvenic shear flow can have either stabilization or destabilization effects on the tearing mode development, which is mostly determined by the shear flow thickness (av). The shear flow tends to boost the tearing mode instability when the thickness of the shear flow is above av ∼ 0.35a (where a is the normalization unit). The boosting effect of the shear flow on the tearing mode becomes strongest at av ∼ 0.6a. But the strength of the boosting and suppressing effects is controlled by the asymptotic velocity (V0) of the shear flow. The suppressing and boosting effects of the shear flow increase with increase of the shear flow velocity. The kinetic energy associated with initial shear flow is reduced when the shear flow has a boosting effect on the tearing mode growth. Copyright 2010 by the American Geophysical Union.