Collaborative Research: Global Response of the Martian Thermosphere to Energetic Pickup Ions

AST-0908472/0908311Fang/Liemon这个合作项目将应用最先进的耦合数值模式来考虑火星热层对高能拾取离子的全球响应。特别是，这项研究将研究氧离子对成分和能量学的轰击效应。大气日冕中的中性成分可以被电离，被太阳风拾取，最终返回与大气相互作用，导致中性粒子逃离火星。这种溅射损失和相关的加热效应还没有包括在任何全球模型中，以考虑火星系统组件之间的耦合。该项目将把火星环境视为一个单一系统，包括火星热层质量和能量预算范围内的拾取离子。这项工作将应用基于磁流体力学的拾取离子传输模型，以及入射高能粒子与外基座以下热层之间相互作用的不同模型，并将溅射和加热效应构建到最先进的火星热层一般环流模型中。直接拾取离子损失和溅射损失的逃逸率估计将用于促进对控制大气侵蚀的非热过程的理解，以及对大气长期演化的量化。这项工作将允许外推火星大气和气候的历史、液态水的可能存在以及行星的宜居性。与航天器的测量结果进行比较将限制对火星-太阳风相互作用的理解。这一结果将对未来的火星探测器航天器具有重要意义，这项研究涉及研究生。对于更广泛的社区来说，火星科学捕捉到了科学探索和冒险的兴奋。因为这个项目有助于了解氧气的流失以及由此导致的水的流失，所以它提供了一个理想的机会，通过公众对火星上的水，或许是生命的关注来提高科学素养。

AST-0908472/0908311Fang/LiemohnThis collaborative project will apply coupled state-of-the-art numerical models to consider the global response of the Martian thermosphere to energetic pickup ions. In particular, the research will study the bombardment effects of oxygen ions on composition and energetics. The neutral constituents of the atmospheric corona can be ionized, picked up by the solar wind, and ultimately returned to interact with the atmosphere, causing neutral particles to escape from Mars. This sputtering loss and associated heating effects have not yet been included in any global models to consider the coupling among the Mars system components. This project will treat the Mars environment as a single system, including pickup ions within the mass and energy budget of the Martian thermosphere. The work will apply a magneto-hydrodynamics field-based pickup ion transport model, along with a different model for the interaction between incident energetic particles and the thermosphere below the exobase, and build the sputtering and heating effects into the state-of-the-art Mars Thermosphere General Circulation Model. The escape rate estimate for direct pickup ion loss and sputtering loss will be used to advance understanding of the non-thermal processes governing atmospheric erosion, and the quantification of long-term atmospheric evolution.This work will permit extrapolation of the history of the Martian atmosphere and climate, the possible presence of liquid water, and planetary habitability. Comparison with spacecraft measurements will constrain understanding of the Mars-solar wind interaction. The results will be important for future Mars probe spacecraft, and the research involves graduate students. For the broader community, Mars sciences capture the excitement of scientific exploration and adventure. Because this project helps to understand oxygen loss and thus water loss, it provides an ideal opportunity to advance scientific literacy through the public interest in water, and perhaps life, on Mars.