The spatiotemporal variability of planetary ions in Mercury

Based on the plasma and magnetic field data of Messenger from 2011 to 2015, we distinguished different regions spatially such as solar wind, magnetic sheath, cusp and magnetic tail.And the following three aspects are studied to obtain an understanding of the spatiotemporal variability of Mercury space planet ions.we found that even before extreme solar activity, there are some changes in the formation mechanism of planetary ions, which can activate high photon ionization in extreme solar wind environments especially in the cusp zone.We analyzed the sodium ions data during 60+ flares eruption, and found that the sodium ion density in the cusp region and the magnetic sheath region increased significantly during this period.During extreme solar activity,we found sodium ions at the magnetic tail decrease significantly and recover after a few days, which is presumed to be due to the convective effect of the magnetic tail excited by the high-energy solar wind.