Global hybrid simulations of highly compressed magnetosphere events at Mercury

The highly compressed magnetosphere (HCM) events at Mercury observed by the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft have been investigated using the global hybrid simulation LatHyS. The HCM events occur due to the interactions with coronal mass ejections (CMEs) or high-speed streams (HSSs) and previous studies indicate that not only the reconnection-driven erosion but also the induced currents in the inner core have an important role in the variation of the dayside magnetosphere of Mercury. However, the effects of the presence of planetary ions on Mercury’s system have not been well discussed. In this study, we mainly focus on the presence of planetary ions that are self-consistently produced from the exosphere by several ionization processes under extreme solar wind conditions and discuss their role on the structure and dynamics of Mercury’s magnetosphere.