Topic“Study on the escaping and returning of ions at the Mars ” in the “Study on the atmospheric escape and particle radiation at the Mars”

Principal Investigator: Dr. Li Kun

Period：2020-2022

Project Description:

In the Earth’s magnetosphere formed by the global intrinsic dipole magnetic field, the magnetic reconnection partially decreases the total ion loss by returning some of the escaping ions. Recent studies found a large number of returning ions at Mars and Venus. On Venus, oxygen ions are returning the planet at a rate on the same order of magnitude as that for oxygen ion escaping, during solar minimum. It is still unknown if the returning oxygen ions are related to the magnetic reconnection in the induced magnetosphere. Further studies are hindered by the limitation of the instruments onboard the Venus Express. Similar to the Venus, the above question remain unclear for Mars. In this study, we use data of high definition and wide field-of-view obtained during a longer time period. We study the cause of the return flow of oxygen ion and try to understand the effects of weakened magnetic field of a planet on the atmospheric loss. We compare it with the ion loss at Earth to understand the atmospheric evolution.