Coupling of Double Tearing Instability with Shear Flow and Solar Flare

The nonlinear behavior of the double tearing mode with shear flow parallel to the magnetic filed is investigated numerically in cylindrical geometry. The double tearing instability is found to be unstable with two peak current density profile, and under the influence of shear flow, it exhibits a complicated behavior in the physical and parameter space. With a Sech form shear flow, it is found that when the velocity shear near the resonant surface is small, the shear flow has a stabilizing effect, but for larger velocity shear, the double tearing modes are destabilized. The Possible physical implications of the coupling of double tearing instability with shear flow for the triggering of solar flares are discussed.