The effect of shear flow on the resistive tearing instability

Abstract

We develop a new scaling theory for the resistive tearing mode instability of a current sheet with a strong shear flow across the layer. The growth rate decreases with increasing flow shear and is completely stabilized as the shear flow becomes Alfvénic: both in the constant-$\Psi$ regime, as in previous results, but we also show that the growth rate is in fact suppressed more strongly in the nonconstant-$\Psi$ regime. As a consequence, for sufficiently large flow shear, the maximum of the growth rate is always affected by the shear suppression, and the wavenumber at which this maximum growth rate is attained is an increasing function of the strength of the flow shear. These results may be important for the onset of reconnection in imbalanced MHD turbulence.

13 pages, 4 figures, submitted to JPP

References in corpus (6)

• Recent progress in astrophysical plasma turbulence from solar wind observations
• Reconnection-Driven Energy Cascade in Magnetohydrodynamic Turbulence
• Plasmoid Instability in Forming Current Sheets
• The magnetic drivers of campfires seen by the Polarimetric and Helioseismic Imager (PHI) on Solar Orbiter
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• Suppression of the collisionless tearing mode by flow shear: implications for reconnection onset in the Alfvénic solar wind