Authors: Chen Shi (UCLA), Marco Velli (UCLA), Anna Tenerani (UT Austin), Anton Artemyev (UCLA)

The stability problem of current sheets is one of the most important topics in space physics as it is directly related to the onset of various explosive energy-release processes such as the solar flares and geomagnetic substorms. In resistive-MHD regime, tearing mode instability can efficiently transfer energy from sheared magnetic field to growing perturbations in magnetic field and plasma flows. Here, we discuss the linear growth rate of tearing instability with various types of current sheet configurations. We analyze the effects of guide field, normal component of magnetic field, and plasma flows. We show (1) The guide field raises the growth rate of oblique mode at large wavenumbers, but it does not affect the most unstable mode, which remains parallel to the reconnecting component of magnetic field. (2) Even a very small normal component of magnetic field can significantly stabilize the tearing mode. (3) A plasma jet flowing along the reconnecting component of magnetic field leads to coupling of the varicose jet instability and the tearing instability. (4) A plasma jet flowing along the guide field direction, together with the guide field, can make the fastest growing mode of the system oblique. We discuss the applications of these results to the pre-eruptive configurations in the solar corona.