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

合作研究：火星热层对高能拾取离子的整体响应

• 批准号: 0908472
• 负责人: Xiaohua Fang
• 金额: $ 17.78万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-15 至 2014-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0908472&HistoricalAwards=false
• 关键词: Collaborative; Research; Global; Response; Martian

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.

这个合作项目将应用最先进的数值模型来考虑火星热层对高能拾取离子的全球响应。特别是研究了氧离子轰击对组分和能量学的影响。大气日冕中的中性成分可以被电离，被太阳风吸收，并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热效应尚未包括在任何考虑火星系统组成部分之间耦合的全球模型中。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范围内的拾取离子。这项工作将应用基于磁流体动力学场的拾取离子输运模型，以及入射高能粒子与外基下面的热层之间相互作用的不同模型，并将溅射和加热效应建立到最先进的火星热层环流模型中。直接吸收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。这项工作将允许推断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。与航天器测量的比较将限制对火星-太阳风相互作用的理解。研究结果将对未来的火星探测器非常重要，而且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损失，从而了解水的损失，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。