Systematic 2.5D resistive MHD simulations with ambipolar diffusion and Hall effect for fast magnetic reconnection

In this work, we explore the possibility of the Hall effect and ambipolar diffusion as a mechanism for fast reconnection. The reconnected flux of our resistive and resistive+Hall simulations replicates the GEM results. Furthermore, we investigate, for the first time, the effect of ambipolar diffusion in the GEM. The reconnected flux of the resistive+ambipolar and resistive+Hall+ambipolar simulations showed increases of up to 75% and 143%, respectively, compared to the resistive and resistive+Hall simulations, showing that ambipolar diffusion contributes significantly to the reconnected flux. Our second scenario has a magnetic Harris field without perturbations but with an out-of-plane component, known as a guide field. We found that the reconnection rate increased faster with ambipolar diffusion, reaching values close to 0.1 for the resistive+Hall+ambipolar simulation followed by the resistive+Hall. These two simulations achieved the highest kinetic energy, implying more efficient energy conversion during reconnection.