Theoretic Study on Formation and Variation of Magnetopause of Planet (Mars)

However, Mars has not intrinsic magnetic field according to the observation. Therefore, the Martian magnetosphere formation is different from the Earth’s. As we know, Mars has an induced magnetosphere. In this paper, to consider the balance between solar wind dynamic pressure and the planetary ionospheric charged particle pressure companying with a weak intrinsic magnetic field pressure, a model for formation of planet (Mars) magnetopause is established. According to the satellite observation, configuration of the dayside Martian magnetopause and its variation in the meridian planes are studied with the model. The results show that the configuration of the dayside Martian magnetopause has some similarities to the geo-magnetopause. The stronger the solar wind dynamic pressure is, the closer the Martian magnetopause to the Mars surface will be. The weaker the solar wind dynamic pressure is, the farther the Martian magnetopause to the Mars surface will be. According to the view that the Martian intrinsic magnetic moment is reducing from ancient times to the present and it would be reversed, the role of the large scale magnetic field to the Martian magnetopause is studied with an assumed intrinsic magnetic moment. Results show that the stronger the intrinsic magnetic moment was, the further the Martian magnetopause to the Mars surface would be. The weaker the intrinsic magnetic moment was, the closer the Martian magnetopause to the Mars surface would be. These results are significant not only to study the long term variation of the Martian magnetosphere, but also to study the configuration of magnetopause in general planet.