3D Multi-Fluid Simulations of the Solar Wind Interaction with Mercury's Magnetosphere

3D multi-fluid simulations are used to predict Mercury's magnetospheric response to forcing from the solar wind. The model includes both heavy and light exospheric ion populations, and differs from the terrestrial magnetosphere in that Mercury's magnetic field is much weaker and solar wind conditions, including dynamic pressure and interplanetary magnetic field (IMF), are much higher. The model predicts that the access of the solar wind to the surface at Mercury is highly asymmetric and dependent on the strength and direction of the IMF. In particular, during southward IMF much of the dayside magnetic field can be eroded and jets/plumes of heavy ions outflow from the surface and move out into the solar wind. Development of substorms and storms in association with flux ropes similar to those at Earth are also seen to occur, but the time scale for their development is much shorter than at Earth. Formation of a symmetric ring current is not seen due to interactions of the plasma with the planet's surface.