Variation of the Jovian Magnetopause Under Constant Solar Wind Conditions: Significance of Magnetodisc Dynamics

Abstract

AbstractIt is generally believed that variations in the upstream solar wind (SW) and interplanetary magnetic field (IMF) conditions are the main cause of changes of Jupiter's magnetopause (JM) location. However, most previous pressure balance models for the JM are axisymmetric and do not consider internal drivers, for example, the dynamics of the magnetodisc. We use three‐dimensional global magnetosphere simulations to investigate the variation of the JM under constant SW/IMF conditions. These simulations show that even without variations in the upstream driving conditions, the JM can exhibit dynamic variations, suggesting a range as large as 50 Jupiter radii in the subsolar location. Our study shows that the interchange structures in the Jovian magnetodisc will introduce significant radial dynamic pressure, which can drive significant variation in the JM location. The results provide important new context for interpreting the JM location and dynamics, with key implications for other internally mass‐loaded and/or rapidly rotating systems.