The Solar Wind-Ionosphere-Thermosphere Coupling at Mars: Combined Data Analysis of Mars Express and MAVEN Observations.

太阳的电磁辐射和高能粒子输出的变化强烈地影响着火星热层的状态。太阳辐射是热层光化学的主要驱动力。太阳紫外线和红外线通量分量（< 800 nm）是造成热层加热的原因，而极紫外线（5-95 nm）和太阳软X射线（0.1-5 nm）则通过光致电离和电子碰撞为电离层的形成提供能量。火星上缺乏全球磁场，导致太阳风与行星电离层/中性大气直接相互作用，从而导致这些域之间的强耦合。行星波、潮汐和重力波从低层大气向上传播到高层大气，是在中层和热层上层沉积能量的其他强大储存库。火星快车和MAVEN仪器观测相结合，为详细调查电离层和热层耦合的时空响应提供了独特的机会。太阳变率的同步观测（例如太阳X射线和EUV通量，利用两个航天器上的仪器在火星上观测太阳风状况和太阳高能粒子通量，结合对大气层/电离层特性的详细观测，将深入了解太阳能在整个相互联系的大气系统中的流动。（Mars Express和MAVEN）和火星太阳风/电离层/热层耦合的多仪器数据分析。本项目将开展一系列综合性的热层/电离层离子和中性粒子同时观测案例研究，研究离子密度和中性粒子密度之间的关系（温度）和潜在的控制因素：太阳风动压、太阳辐照度和行星际磁场的变化，将研究由不同类型的热层波驱动的电离层风发电机的影响。该项目将由RIU的Rheinisches Institut für Umweltforschung an der Universität zu Köln与位于哥廷根的Max Planck Institute for Solar System Research MPS合作进行。实验和理论专业知识相结合，在数据分析方面的丰富经验和专门参与火星快车（PI和Co-I-ships）上的实验以及与MAVEN科学团队的密切合作，使该项目在研究火星太阳风/电离层/热层耦合方面处于突出地位。

The variability of the Sun’s electromagnetic radiation and energetic particle output strongly affects the state of the Martian thermosphere. The solar radiation is the main driver of the thermospheric photo-chemistry. The solar ultra-violet and infra-red flux components (< 800 nm) are responsible for the thermospheric heating, while the EUV (5–95 nm) and soft solar X-ray (0.1–5 nm) provide the energy for the formation of the ionosphere by photo-ionization and electron impact. The absence of a global magnetic field at Mars leads to the direct interaction of the solar wind with the planetary ionosphere/neutral atmosphere and therefore to a strong coupling between these domains. Planetary waves, tides, and gravity waves, which are propagating upward from the lower to the upper atmosphere, are other powerful reservoirs for the deposition of energy in the upper mesosphere and thermosphere. The combination of Mars Express and MAVEN instrument observations provides the unique opportunity for a detailed investigation of the temporal and spatial response of the coupling of the ionosphere and thermosphere. Simultaneous observations of the solar variability (e.g. the solar X-ray and EUV flux, solar wind conditions and solar energetic particle flux) at Mars by instruments on both spacecraft in combination with detailed observation of the atmospheric/ionospheric characteristics will give deep insights into the flow of the solar energy throughout the strongly interconnected atmospheric system.We propose a dual-spacecraft (Mars Express and MAVEN) and multi-instrument data analysis of the solar wind/ionosphere/thermosphere coupling at Mars. This project shall conduct a series of comprehensive case studies of simultaneous observations of ions and neutrals in the thermosphere/ionosphere, investigate the relationship between the ion and neutral densities (temperatures) and potential controlling factors: variations of the solar wind dynamic pressure, the solar irradiance and the interplanetary magnetic field, shall study effects of the ionospheric wind dynamo driven by the different types of thermospheric waves. The project will be performed by the Rheinisches Institut für Umweltforschung an der Universität zu Köln, RIU, in collaboration with the Max Planck Institute for Solar System Research MPS in Göttingen. The combination of experimental and theoretical expertise, high experience in data analysis and exclusive involvement with experiments on Mars Express (PI and Co-I-ships) and the close collaboration with the MAVEN science team put this project in an outstanding position for the study of solar wind/ionosphere/thermosphere coupling at Mars.