Escape of planetary ions from Mercurys magnetosphere under different solar wind conditions
Résumé
The combination of a weak intrinsic magnetic field and strong solar wind conditions at Mercury results in the formation of a relatively small magnetosphere compared to that of the Earth. Typical bowshock and magnetopause locations at Mercury are 2 and 1.4 Mercury radius from the center of the planet, respectively, and thus, Mercurys mini-magnetosphere is strongly compressed and may disappear when solar wind condition is extreme. Under these particular circumstances, the solar wind can directly interact with its exosphere and surface and planetary ion escape is expected to be enhanced. In this study, the production and escape of planetary ions from the exosphere have been investigated under different solar wind conditions using the global hybrid simulation LatHyS. In particular, we have focused on dynamic pressure and interplanetary magnetic field dependence. This study will provide a good indication on the ability of a mini-magnetosphere to protect the planetary exosphere from ion escape, to be compared to that of the larger magnetosphere of the Earth.