How tail reconnection affects the asymmetric state of the magnetosphere in the LFM model

The IMF B_y component is a source of numerous asymmetric features in our magnetospheric system, e.g. north-south asymmetries in the aurora, the magnetospheric and ionospheric current systems and the plasma convection. Several recent studies have shown that asymmetries in the lobe pressure play a major role in inducing these asymmetries. It has also been reported that enhanced tail reconnection affects the dynamics of the system by reducing the north-south asymmetries imposed by the IMF. A possible interpretation of these observations is that enhanced reconnection in the near-Earth tail reduces the pressure in the lobes and thus suppresses the cause of the initial asymmetry. In this study, we present the results from global MHD simulations using the LFM model to further investigate how enhanced tail reconnection affects the asymmetric state of the system. A relaxation of the asymmetry in the closed magnetosphere is seen in the model when the reconnection rate in the tail increases, consistent with observations, and we use the simulation output to gain further insight into the physical mechanism(s) responsible for the return to a more symmetric state.