AI 中文总结
该研究借助MAVEN与天问一号的联合观测，证实开尔文-亥姆霍兹不稳定性是火星等离子体云（整体离子逃逸载体）的起源，其离子通量远高于稳态通道，揭示了KHI对无磁行星大气离子逃逸的关键作用。
AI 中文摘要
太阳风驱动的大气离子逃逸是控制火星大气长期损失的关键过程。局地等离子体云可携带大量行星离子通量离开火星，代表着整体逃逸事件，但由于缺乏上游同步测量，其起源仍不明确。利用MAVEN与天问一号任务的联合观测（提供实时上游监测），我们获得直接证据表明这些等离子体云是由开尔文-亥姆霍兹不稳定性（KHI）产生的非线性波包，首次通过两点测量约束了KH波的空间尺度。等离子体云内的离子通量比典型稳态逃逸通道高1至2个数量级。我们的结果表明，KHI是太阳风与行星高层大气耦合的重要过程，对无磁行星的大气离子逃逸起着关键作用。
英文摘要
Atmospheric ion escape driven by the solar wind is a key process controlling the long-term loss of the Martian atmosphere. Localized plasma clouds can carry substantial fluxes of planetary ions away from Mars, representing episodes of bulk escape. However, their origin has remained unclear due to the absence of simultaneous upstream measurements. Using joint observations from the MAVEN and Tianwen-1 missions, which provide real-time upstream monitoring, we present direct evidence that these plasma clouds are nonlinear wave packets generated by the Kelvin-Helmholtz instability (KHI). The spatial scale of KH waves is constrained for the first time via two-point measurements. Ion fluxes within plasma clouds are one to two orders of magnitude higher than those in typical steady-state escape channels. Our results indicate that KHI is an important process for solar wind coupling to planetary upper atmospheres and plays a crucial role in shaping atmospheric ion escape for unmagnetized planets.
