Solar Wind - Magnetosphere Coupling via Kelvin-Helmohltz Instability at Mercury

Kelvin-Helmohltz instability (KHI) generated by velocity shear in the vicinity of the magnetopause has been considered to play an important role in the energy transfer and momentum coupling between the solar wind and planetary magnetospheres. The related processes have been investigated by spacecraft observations at Earth, Jupiter and Saturn. Measurements by the MESSENGER spacecraft will add a wealth of new information on KHI for a small-sized magnetosphere where finite gyroradius effect could be important. To explore this issue, we have started by employing MHD calculation to make parametric study of the wave growth effect at Mercury’s magnetopause using a set of boundary conditions and plasma parameters from hybrid simulations of the M1 and M2 encounters of the MESSENGER spacecraft with Mercury in 2008.