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

AST-0908472/0908311 Fang/Liemohn这个合作项目将应用最先进的耦合数值模型来考虑火星热层对高能拾取离子的全球响应。 特别是，该研究将研究氧离子对成分和能量学的轰击效应。 大气日冕的中性成分可以被电离，被太阳风带走，最终返回与大气相互作用，导致中性粒子从火星逃逸。 这种溅射损失和相关的加热效应尚未被纳入任何全球模型，以考虑火星系统各组成部分之间的耦合。 该项目将把火星环境视为一个单一的系统，包括在火星热层的质量和能量预算内拾取离子。 这项工作将应用一个基于磁流体力学场的拾取离子传输模型，沿着一个不同的模型，用于入射高能粒子与外底以下的热层之间的相互作用，并将溅射和加热效应纳入最先进的火星热层环流模型。 对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，以及对长期大气演变的量化，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可居住性。 与航天器测量结果的比较将限制对火星-太阳风相互作用的理解。 这些结果对未来的火星探测器很重要，研究涉及研究生。 对于更广泛的社区，火星科学捕捉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，从而了解水分的流失，它提供了一个理想的机会，通过公众对火星上的水，甚至生命的兴趣来提高科学素养。

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.