Journal article
Role of ULF Waves in Reforming the Martian Bow Shock
AGU advances, Vol.6(4), e2025AV001654
08/2025
DOI: 10.1029/2025AV001654
Abstract
Understanding the nature of planetary bow shocks is beneficial for advancing our knowledge of solar wind interactions with planets and fundamental plasma physics processes. Here, we utilize data from the Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft to investigate the Martian bow shock, revealing its distinctive characteristics within our solar system. We find that unlike other planetary shocks, the reformation of Mars's bow shock driven by the ultra‐low frequency (ULF) waves is more global and less dependent on shock geometries. This distinct behavior is attributed to the broad distribution of ULF waves in the upstream region at Mars, generated not only by shock‐reflected ions but also by planetary protons. Additionally, during the reformation process, the amplitude of the ULF waves and the steepened structures are significantly large. This results in the newly reformed shock exceeding the original one, a phenomenon not observed at other planets under similar shock conditions. Therefore, the ULF waves significantly enhance the complexity of shock dynamics and play a more substantial role at Mars compared to other planets.
The Sun continuously emits a high‐speed plasma flow into interplanetary space, known as the solar wind. When this solar wind encounters Mars, a bow shock forms in front of Mars, decelerating and heating the incoming solar wind. This bow shock plays a pivotal role in mediating interactions between the solar wind and Mars. The bow shock may undergo cyclical reformations, meaning that the shock is periodically re‐established over time. In this study, we utilize observations from spacecraft to study the Martian bow shock reformation. We discovered that the reformation processes of the Martian bow shock exhibit distinctive characteristics not seen at other planets. Specifically, we show that shock reformation, typically restricted to only parts of the shock at other planets, may occur throughout the entire Martian bow shock and under a wider range of conditions. Our findings suggest that the Martian bow shock serves as an uniquely valuable laboratory for studying shock phenomena and the underlying fundamental plasma physics.
The reformation of the Martian bow shock exhibits distinctive characteristics that set it apart from those observed at other planets Shock reformation driven by ultra‐low frequency (ULF) waves at Mars is less dependent on shock geometry compared to other planets ULF waves periodically modulate the local shock geometry, thereby influencing the motion of reflected ions
Details
- Title: Subtitle
- Role of ULF Waves in Reforming the Martian Bow Shock
- Creators
- Chi Zhang - Boston UniversityChuanfei Dong - Boston UniversityTerry Z. Liu - Planetary Science InstituteChristian Mazelle - Université de ToulouseSavvas Raptis - Johns Hopkins University Applied Physics LaboratoryHongyang Zhou - Boston UniversityJacob Fruchtman - University of IowaJasper Halekas - University of IowaJing‐Huan Li - Swedish Institute of Space PhysicsKathleen G. Hanley - University of California, BerkeleyShannon M. Curry - Laboratory for Atmospheric and Space PhysicsDavid L. Mitchell - University of California, BerkeleyXinmin Li - Boston University
- Resource Type
- Journal article
- Publication Details
- AGU advances, Vol.6(4), e2025AV001654
- DOI
- 10.1029/2025AV001654
- ISSN
- 2576-604X
- eISSN
- 2576-604X
- Publisher
- AMER GEOPHYSICAL UNION
- Grant note
- NASAAlfred P. Sloan Research FellowshipJohns Hopkins University Applied Physics Laboratory independent RD fundFrench space agency CNES (National Centre for Space Studies)
This work was partially supported by NASA Grant NNH10CC04C through the MAVEN Project, NASA Grants 80NSSC23K0911 and 80NSSC24K1843, and the Alfred P. Sloan Research Fellowship. SR acknowledges support from the Johns Hopkins University Applied Physics Laboratory independent R&D fund. Parts of this work for the observations obtained with the SWEA instrument are supported by the French space agency CNES (National Centre for Space Studies). We acknowledge fruitful discussions with James P. McFadden.
- Language
- English
- Date published
- 08/2025
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984927083102771
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