Non-driven Reconnection as a function of guide field strength

It is now generally accepted that magnetic reconnection is the dominant process at the magnetopause that enables the transfer of mass, momentum, and energy from the solar wind into the Earth's magnetosphere. Observations have also shown that magnetic reconnection at the magnetopause can sometimes be quasi-steady but at other times very unsteady (resulting in so-called flux transfer events). The reason for this dual behavior is, however, not understood. Another issue of considerable controversy is the existence of a "universal" reconnection rate, independent of the system size. Here we use a combination of hybrid (electron fluid, kinetic ions) and full particle simulations to address these issues. Our previous work using hybrid simulations has shown that reconnection can be intermittent even in the anti-parallel case. It is not clear whether this result remains in the presence of kinetic electron physics. In order to minimize the influences of initial imposed perturbations on the simulation results, we start the simulations with an island kinetic equilibrium and let the system evolve self-consistently. We compare the nonlinear evolution of the system as a function of guide field strength and system size and test the hypothesis of a "universal" reconnection rate. The conditions for steady state reconnection and relevance of results to magnetopause will be discussed.