Martian Bow Shock Oscillations Driven by Solar Wind Variations: Simultaneous Observations From Tianwen-1 and MAVEN

Abstract

The Martian bow shock stands as the first defense against the solar wind and shapes the Martian magnetosphere. Previous studies showed the correlation between the Martian bow shock location and solar wind parameters. Here we present direct evidence of solar wind effects on the Martian bow shock by analyzing Tianwen-1 and MAVEN data. We examined three cases where Tianwen-1 data show rapid oscillations of the bow shock, while MAVEN data record changes in solar wind plasma and magnetic field. The results indicate that the bow shock is rapidly compressed and then expanded during the dynamic pressure pulse in the solar wind, and is also oscillated during the IMF rotation. The superposition of variations in multiple solar wind parameters leads to more intensive bow shock oscillation. This study emphasizes the importance of joint observations by Tianwen-1 and MAVEN for studying the real-time response of the Martian magnetosphere to the solar wind.